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stable-rc/queue/4.19 baseline: 185 runs, 1 regressions (v4.19.155-71-gf085febade75)

by kernelci.org bot

stable-rc/queue/4.19 baseline: 185 runs, 1 regressions (v4.19.155-71-gf085febade75) Regressions Summary ------------------- platform | arch | lab | compiler | defconfig | regressions ---------+------+---------------+----------+---------------------+------------ panda | arm | lab-collabora | gcc-8 | omap2plus_defconfig | 1 Details: https://kernelci.org/test/job/stable-rc/branch/queue%2F4.19/kernel/v4.19.15… Test: baseline Tree: stable-rc Branch: queue/4.19 Describe: v4.19.155-71-gf085febade75 URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git SHA: f085febade758516e98b6231ac0a63c42c4fe3cb Test Regressions ---------------- platform | arch | lab | compiler | defconfig | regressions ---------+------+---------------+----------+---------------------+------------ panda | arm | lab-collabora | gcc-8 | omap2plus_defconfig | 1 Details: https://kernelci.org/test/plan/id/5faa724dc8341cd6fadb8875 Results: 4 PASS, 1 FAIL, 0 SKIP Full config: omap2plus_defconfig Compiler: gcc-8 (arm-linux-gnueabihf-gcc (Debian 8.3.0-2) 8.3.0) Plain log: https://storage.kernelci.org//stable-rc/queue-4.19/v4.19.155-71-gf085febade… HTML log: https://storage.kernelci.org//stable-rc/queue-4.19/v4.19.155-71-gf085febade… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d… * baseline.dmesg.emerg: https://kernelci.org/test/case/id/5faa724dc8341cd6fadb887a new failure (last pass: v4.19.155-71-gcb057990947da) 2 lines

4 years, 7 months

stable/linux-5.4.y build: 197 builds: 1 failed, 196 passed, 1 error, 109 warnings (v5.4.76)

by kernelci.org bot

stable/linux-5.4.y build: 197 builds: 1 failed, 196 passed, 1 error, 109 warnings (v5.4.76) Full Build Summary: https://kernelci.org/build/stable/branch/linux-5.4.y/kernel/v5.4.76/ Tree: stable Branch: linux-5.4.y Git Describe: v5.4.76 Git Commit: ec9c6b417e271ee76d1430d2b197794858238d3b Git URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git Built: 7 unique architectures Build Failure Detected: mips: ip27_defconfig: (gcc-8) FAIL Errors and Warnings Detected: arc: allnoconfig (gcc-8): 1 warning axs103_defconfig (gcc-8): 2 warnings axs103_smp_defconfig (gcc-8): 2 warnings haps_hs_defconfig (gcc-8): 2 warnings haps_hs_smp_defconfig (gcc-8): 2 warnings hsdk_defconfig (gcc-8): 2 warnings nsim_hs_defconfig (gcc-8): 2 warnings nsim_hs_smp_defconfig (gcc-8): 2 warnings nsimosci_hs_defconfig (gcc-8): 2 warnings nsimosci_hs_smp_defconfig (gcc-8): 2 warnings tinyconfig (gcc-8): 1 warning vdk_hs38_defconfig (gcc-8): 1 warning vdk_hs38_smp_defconfig (gcc-8): 1 warning arm64: defconfig (gcc-8): 14 warnings arm: am200epdkit_defconfig (gcc-8): 1 warning assabet_defconfig (gcc-8): 1 warning at91_dt_defconfig (gcc-8): 1 warning axm55xx_defconfig (gcc-8): 1 warning cm_x2xx_defconfig (gcc-8): 1 warning cm_x300_defconfig (gcc-8): 1 warning cns3420vb_defconfig (gcc-8): 1 warning colibri_pxa270_defconfig (gcc-8): 1 warning colibri_pxa300_defconfig (gcc-8): 1 warning collie_defconfig (gcc-8): 1 warning davinci_all_defconfig (gcc-8): 1 warning dove_defconfig (gcc-8): 1 warning em_x270_defconfig (gcc-8): 1 warning ep93xx_defconfig (gcc-8): 1 warning eseries_pxa_defconfig (gcc-8): 1 warning exynos_defconfig (gcc-8): 1 warning ezx_defconfig (gcc-8): 1 warning h3600_defconfig (gcc-8): 1 warning h5000_defconfig (gcc-8): 1 warning imote2_defconfig (gcc-8): 1 warning imx_v4_v5_defconfig (gcc-8): 1 warning imx_v6_v7_defconfig (gcc-8): 1 warning integrator_defconfig (gcc-8): 1 warning ixp4xx_defconfig (gcc-8): 1 warning keystone_defconfig (gcc-8): 1 warning lpc32xx_defconfig (gcc-8): 1 warning magician_defconfig (gcc-8): 1 warning milbeaut_m10v_defconfig (gcc-8): 1 warning mini2440_defconfig (gcc-8): 1 warning mmp2_defconfig (gcc-8): 1 warning multi_v5_defconfig (gcc-8): 1 warning multi_v7_defconfig (gcc-8): 1 warning mv78xx0_defconfig (gcc-8): 1 warning mvebu_v5_defconfig (gcc-8): 1 warning mvebu_v7_defconfig (gcc-8): 1 warning mxs_defconfig (gcc-8): 1 warning neponset_defconfig (gcc-8): 1 warning nhk8815_defconfig (gcc-8): 1 warning omap1_defconfig (gcc-8): 1 warning omap2plus_defconfig (gcc-8): 1 warning orion5x_defconfig (gcc-8): 1 warning oxnas_v6_defconfig (gcc-8): 1 warning palmz72_defconfig (gcc-8): 1 warning pcm027_defconfig (gcc-8): 1 warning prima2_defconfig (gcc-8): 1 warning pxa168_defconfig (gcc-8): 1 warning pxa3xx_defconfig (gcc-8): 1 warning pxa910_defconfig (gcc-8): 1 warning qcom_defconfig (gcc-8): 1 warning realview_defconfig (gcc-8): 1 warning s3c6400_defconfig (gcc-8): 1 warning s5pv210_defconfig (gcc-8): 1 warning sama5_defconfig (gcc-8): 1 warning shannon_defconfig (gcc-8): 1 warning spear13xx_defconfig (gcc-8): 1 warning sunxi_defconfig (gcc-8): 1 warning tango4_defconfig (gcc-8): 1 warning tegra_defconfig (gcc-8): 1 warning trizeps4_defconfig (gcc-8): 1 warning u300_defconfig (gcc-8): 1 warning u8500_defconfig (gcc-8): 1 warning versatile_defconfig (gcc-8): 1 warning vexpress_defconfig (gcc-8): 1 warning viper_defconfig (gcc-8): 1 warning xcep_defconfig (gcc-8): 1 warning zeus_defconfig (gcc-8): 1 warning i386: mips: ip27_defconfig (gcc-8): 1 error riscv: rv32_defconfig (gcc-8): 6 warnings x86_64: tinyconfig (gcc-8): 1 warning Errors summary: 1 /scratch/linux/arch/mips/pci/pci-xtalk-bridge.c:287:9: error: ‘struct bridge_irq_chip_data’ has no member named ‘nnasid’; did you mean ‘nasid’? Warnings summary: 61 WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL 24 <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] 5 /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] 2 <stdin>:830:2: warning: #warning syscall fstat64 not implemented [-Wcpp] 2 <stdin>:1127:2: warning: #warning syscall fstatat64 not implemented [-Wcpp] 2 /scratch/linux/arch/arm64/include/asm/memory.h:239:15: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] 2 /scratch/linux/arch/arm64/boot/dts/exynos/exynos5433.dtsi:254.3-29: Warning (reg_format): /gpu@14ac0000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 2) 1 arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' 1 arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' 1 /scratch/linux/arch/arm64/boot/dts/exynos/exynos7.dtsi:83.3-29: Warning (reg_format): /gpu@14ac0000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 2) 1 .config:1156:warning: override: UNWINDER_GUESS changes choice state Section mismatches summary: 1 WARNING: vmlinux.o(.text.unlikely+0x3484): Section mismatch in reference from the function pmax_setup_memory_region() to the function .init.text:add_memory_region() 1 WARNING: vmlinux.o(.text.unlikely+0x3110): Section mismatch in reference from the function pmax_setup_memory_region() to the function .init.text:add_memory_region() ================================================================================ Detailed per-defconfig build reports: -------------------------------------------------------------------------------- 32r2el_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (arc, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- allnoconfig (riscv, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (i386, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (arm64, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (x86_64, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- allnoconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- am200epdkit_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- ar7_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- aspeed_g4_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- aspeed_g5_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- assabet_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] -------------------------------------------------------------------------------- at91_dt_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- ath25_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ath79_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- axm55xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- axs103_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- axs103_smp_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- badge4_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bcm2835_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bcm47xx_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bcm63xx_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bigsur_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bmips_be_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- bmips_stb_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- capcella_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- cavium_octeon_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- cerfcube_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ci20_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- clps711x_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- cm_x2xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- cm_x300_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- cns3420vb_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- cobalt_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- colibri_pxa270_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- colibri_pxa300_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- collie_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] -------------------------------------------------------------------------------- corgi_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- davinci_all_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- db1xxx_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- decstation_64_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- decstation_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches Section mismatches: WARNING: vmlinux.o(.text.unlikely+0x3484): Section mismatch in reference from the function pmax_setup_memory_region() to the function .init.text:add_memory_region() -------------------------------------------------------------------------------- decstation_r4k_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches Section mismatches: WARNING: vmlinux.o(.text.unlikely+0x3110): Section mismatch in reference from the function pmax_setup_memory_region() to the function .init.text:add_memory_region() -------------------------------------------------------------------------------- defconfig (riscv, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- defconfig (arm64, gcc-8) — PASS, 0 errors, 14 warnings, 0 section mismatches Warnings: /scratch/linux/arch/arm64/include/asm/memory.h:239:15: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] /scratch/linux/arch/arm64/include/asm/memory.h:239:15: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] /scratch/linux/arch/arm64/boot/dts/exynos/exynos5433.dtsi:254.3-29: Warning (reg_format): /gpu@14ac0000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 2) arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos5433-tm2.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' /scratch/linux/arch/arm64/boot/dts/exynos/exynos5433.dtsi:254.3-29: Warning (reg_format): /gpu@14ac0000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 2) arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos5433-tm2e.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' /scratch/linux/arch/arm64/boot/dts/exynos/exynos7.dtsi:83.3-29: Warning (reg_format): /gpu@14ac0000:reg: property has invalid length (8 bytes) (#address-cells == 2, #size-cells == 2) arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (pci_device_bus_num): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (i2c_bus_reg): Failed prerequisite 'reg_format' arch/arm64/boot/dts/exynos/exynos7-espresso.dtb: Warning (spi_bus_reg): Failed prerequisite 'reg_format' -------------------------------------------------------------------------------- dove_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- e55_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ebsa110_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- em_x270_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- ep93xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- eseries_pxa_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- exynos_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- ezx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- footbridge_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- fuloong2e_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- gcw0_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- gemini_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- gpr_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- h3600_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] -------------------------------------------------------------------------------- h5000_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- hackkit_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- haps_hs_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- haps_hs_smp_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- hisi_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- hsdk_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- i386_defconfig (i386, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- imote2_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- imx_v4_v5_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- imx_v6_v7_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- integrator_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- iop32x_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ip22_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ip27_defconfig (mips, gcc-8) — FAIL, 1 error, 0 warnings, 0 section mismatches Errors: /scratch/linux/arch/mips/pci/pci-xtalk-bridge.c:287:9: error: ‘struct bridge_irq_chip_data’ has no member named ‘nnasid’; did you mean ‘nasid’? -------------------------------------------------------------------------------- ip28_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ip32_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- ixp4xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- jazz_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- jmr3927_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- jornada720_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- keystone_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- lart_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- lasat_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- lemote2f_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- loongson1b_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- loongson1c_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- loongson3_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- lpc18xx_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- lpc32xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- lpd270_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- lubbock_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- magician_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mainstone_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- malta_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- malta_kvm_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- malta_kvm_guest_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- malta_qemu_32r6_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- maltaaprp_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- maltasmvp_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- maltasmvp_eva_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- maltaup_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- maltaup_xpa_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- markeins_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- milbeaut_m10v_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mini2440_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mips_paravirt_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- mmp2_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- moxart_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- mpc30x_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- mps2_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- msp71xx_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- mtx1_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- multi_v4t_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- multi_v5_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- multi_v7_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mv78xx0_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mvebu_v5_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mvebu_v7_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- mxs_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- neponset_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] -------------------------------------------------------------------------------- netwinder_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- nhk8815_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- nlm_xlp_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- nlm_xlr_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- nsim_hs_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- nsim_hs_smp_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- nsimosci_hs_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- nsimosci_hs_smp_defconfig (arc, gcc-8) — PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- omap1_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- omap2plus_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- omega2p_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- orion5x_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- oxnas_v6_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- palmz72_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pcm027_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pic32mzda_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- pistachio_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- pnx8335_stb225_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- prima2_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pxa168_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pxa255-idp_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- pxa3xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pxa910_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- pxa_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- qcom_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- qi_lb60_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- rb532_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- rbtx49xx_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- realview_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- rm200_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- rpc_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- rt305x_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- rv32_defconfig (riscv, gcc-8) — PASS, 0 errors, 6 warnings, 0 section mismatches Warnings: <stdin>:830:2: warning: #warning syscall fstat64 not implemented [-Wcpp] <stdin>:1127:2: warning: #warning syscall fstatat64 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] <stdin>:830:2: warning: #warning syscall fstat64 not implemented [-Wcpp] <stdin>:1127:2: warning: #warning syscall fstatat64 not implemented [-Wcpp] <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- s3c2410_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- s3c6400_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- s5pv210_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- sama5_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- sb1250_swarm_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- shannon_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: /scratch/linux/drivers/video/fbdev/sa1100fb.c:975:21: warning: ‘sa1100fb_min_dma_period’ defined but not used [-Wunused-function] -------------------------------------------------------------------------------- shmobile_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- simpad_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- socfpga_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- spear13xx_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- spear3xx_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- spear6xx_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- spitz_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- stm32_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- sunxi_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- tango4_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- tb0219_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tb0226_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tb0287_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tct_hammer_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tegra_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- tinyconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tinyconfig (i386, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tinyconfig (arc, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- tinyconfig (riscv, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tinyconfig (x86_64, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: .config:1156:warning: override: UNWINDER_GUESS changes choice state -------------------------------------------------------------------------------- tinyconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- tinyconfig (arm64, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- trizeps4_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- u300_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- u8500_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- vdk_hs38_defconfig (arc, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- vdk_hs38_smp_defconfig (arc, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] -------------------------------------------------------------------------------- versatile_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- vexpress_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- vf610m4_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- viper_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- vt8500_v6_v7_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- workpad_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- x86_64_defconfig (x86_64, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- xcep_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- xway_defconfig (mips, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- zeus_defconfig (arm, gcc-8) — PASS, 0 errors, 1 warning, 0 section mismatches Warnings: WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL -------------------------------------------------------------------------------- zx_defconfig (arm, gcc-8) — PASS, 0 errors, 0 warnings, 0 section mismatches --- For more info write to <info(a)kernelci.org>

4 years, 7 months

[PATCH v3 4/4] pinctrl: amd: remove debounce filter setting in IRQ type setting

by Coiby Xu

Debounce filter setting should be independent from IRQ type setting because according to the ACPI specs, there are separate arguments for specifying debounce timeout and IRQ type in GpioIo() and GpioInt(). This will fix broken touchpads for laptops whose BIOS set the debounce timeout to a relatively large value. For example, the BIOS of Lenovo Legion-5 AMD gaming laptops including 15ARH05 (R7000) and R7000P set the debounce timeout to 124.8ms. This led to the kernel receiving only ~7 HID reports per second from the Synaptics touchpad (MSFT0001:00 06CB:7F28). Existing touchpads like [1][2] are not troubled by this bug because the debounce timeout has been set to 0 by the BIOS before enabling the debounce filter in setting IRQ type. [1] https://github.com/Syniurge/i2c-amd-mp2/issues/11#issuecomment-721331582 [2] https://forum.manjaro.org/t/random-short-touchpad-freezes/30832/28 Cc: Hans de Goede <hdegoede(a)redhat.com> Cc: Andy Shevchenko <andy.shevchenko(a)gmail.com> Cc: Benjamin Tissoires <benjamin.tissoires(a)redhat.com> Cc: stable(a)vger.kernel.org Reviewed-by: Andy Shevchenko <andy.shevchenko(a)gmail.com> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1887190 Link: https://lore.kernel.org/linux-gpio/CAHp75VcwiGREBUJ0A06EEw-SyabqYsp%2Bdqs2D… Signed-off-by: Coiby Xu <coiby.xu(a)gmail.com> --- drivers/pinctrl/pinctrl-amd.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c index e9b761c2b77a..2d4acf21117c 100644 --- a/drivers/pinctrl/pinctrl-amd.c +++ b/drivers/pinctrl/pinctrl-amd.c @@ -468,7 +468,6 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg &= ~BIT(LEVEL_TRIG_OFF); pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= ACTIVE_HIGH << ACTIVE_LEVEL_OFF; - pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF; irq_set_handler_locked(d, handle_edge_irq); break; @@ -476,7 +475,6 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg &= ~BIT(LEVEL_TRIG_OFF); pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= ACTIVE_LOW << ACTIVE_LEVEL_OFF; - pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF; irq_set_handler_locked(d, handle_edge_irq); break; @@ -484,7 +482,6 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg &= ~BIT(LEVEL_TRIG_OFF); pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= BOTH_EADGE << ACTIVE_LEVEL_OFF; - pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF; irq_set_handler_locked(d, handle_edge_irq); break; @@ -492,8 +489,6 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg |= LEVEL_TRIGGER << LEVEL_TRIG_OFF; pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= ACTIVE_HIGH << ACTIVE_LEVEL_OFF; - pin_reg &= ~(DB_CNTRl_MASK << DB_CNTRL_OFF); - pin_reg |= DB_TYPE_PRESERVE_LOW_GLITCH << DB_CNTRL_OFF; irq_set_handler_locked(d, handle_level_irq); break; @@ -501,8 +496,6 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg |= LEVEL_TRIGGER << LEVEL_TRIG_OFF; pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= ACTIVE_LOW << ACTIVE_LEVEL_OFF; - pin_reg &= ~(DB_CNTRl_MASK << DB_CNTRL_OFF); - pin_reg |= DB_TYPE_PRESERVE_HIGH_GLITCH << DB_CNTRL_OFF; irq_set_handler_locked(d, handle_level_irq); break; -- 2.28.0

4 years, 7 months

stable/linux-4.4.y baseline: 122 runs, 4 regressions (v4.4.242)

by kernelci.org bot

stable/linux-4.4.y baseline: 122 runs, 4 regressions (v4.4.242) Regressions Summary ------------------- platform | arch | lab | compiler | defconfig | regressions -----------------+--------+--------------+----------+------------------+------------ qemu_i386 | i386 | lab-baylibre | gcc-8 | i386_defconfig | 1 qemu_i386-uefi | i386 | lab-baylibre | gcc-8 | i386_defconfig | 1 qemu_x86_64 | x86_64 | lab-baylibre | gcc-8 | x86_64_defconfig | 1 qemu_x86_64-uefi | x86_64 | lab-baylibre | gcc-8 | x86_64_defconfig | 1 Details: https://kernelci.org/test/job/stable/branch/linux-4.4.y/kernel/v4.4.242/pla… Test: baseline Tree: stable Branch: linux-4.4.y Describe: v4.4.242 URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git SHA: ad5e80d0d772cea9c08eceaceda3b30131cdaaac Test Regressions ---------------- platform | arch | lab | compiler | defconfig | regressions -----------------+--------+--------------+----------+------------------+------------ qemu_i386 | i386 | lab-baylibre | gcc-8 | i386_defconfig | 1 Details: https://kernelci.org/test/plan/id/5faa62a29785e9770ddb8879 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: i386_defconfig Compiler: gcc-8 (gcc (Debian 8.3.0-6) 8.3.0) Plain log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/i386/i386_defconf… HTML log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/i386/i386_defconf… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d… * baseline.login: https://kernelci.org/test/case/id/5faa62a29785e9770ddb887a new failure (last pass: v4.4.241) platform | arch | lab | compiler | defconfig | regressions -----------------+--------+--------------+----------+------------------+------------ qemu_i386-uefi | i386 | lab-baylibre | gcc-8 | i386_defconfig | 1 Details: https://kernelci.org/test/plan/id/5faa628c0c5823cb28db885f Results: 0 PASS, 1 FAIL, 0 SKIP Full config: i386_defconfig Compiler: gcc-8 (gcc (Debian 8.3.0-6) 8.3.0) Plain log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/i386/i386_defconf… HTML log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/i386/i386_defconf… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d… * baseline.login: https://kernelci.org/test/case/id/5faa628c0c5823cb28db8860 new failure (last pass: v4.4.241) platform | arch | lab | compiler | defconfig | regressions -----------------+--------+--------------+----------+------------------+------------ qemu_x86_64 | x86_64 | lab-baylibre | gcc-8 | x86_64_defconfig | 1 Details: https://kernelci.org/test/plan/id/5faa6270b8c3eba4b3db8862 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: x86_64_defconfig Compiler: gcc-8 (gcc (Debian 8.3.0-6) 8.3.0) Plain log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/x86_64/x86_64_def… HTML log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/x86_64/x86_64_def… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d… * baseline.login: https://kernelci.org/test/case/id/5faa6270b8c3eba4b3db8863 new failure (last pass: v4.4.241) platform | arch | lab | compiler | defconfig | regressions -----------------+--------+--------------+----------+------------------+------------ qemu_x86_64-uefi | x86_64 | lab-baylibre | gcc-8 | x86_64_defconfig | 1 Details: https://kernelci.org/test/plan/id/5faa6259d757146610db8857 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: x86_64_defconfig Compiler: gcc-8 (gcc (Debian 8.3.0-6) 8.3.0) Plain log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/x86_64/x86_64_def… HTML log: https://storage.kernelci.org//stable/linux-4.4.y/v4.4.242/x86_64/x86_64_def… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/kci-2020.05-4-g97706c5d… * baseline.login: https://kernelci.org/test/case/id/5faa6259d757146610db8858 new failure (last pass: v4.4.241)

4 years, 7 months

[PATCH v2 1/9] KVM: arm64: Introduce handling of AArch32 TTBCR2 traps

by Marc Zyngier

ARMv8.2 introduced TTBCR2, which shares TCR_EL1 with TTBCR. Gracefully handle traps to this register when HCR_EL2.TVM is set. Cc: stable(a)vger.kernel.org Reported-by: James Morse <james.morse(a)arm.com> Signed-off-by: Marc Zyngier <maz(a)kernel.org> --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/sys_regs.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 7a1faf917f3c..803cb2427b54 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -212,6 +212,7 @@ enum vcpu_sysreg { #define c2_TTBR1 (TTBR1_EL1 * 2) /* Translation Table Base Register 1 */ #define c2_TTBR1_high (c2_TTBR1 + 1) /* TTBR1 top 32 bits */ #define c2_TTBCR (TCR_EL1 * 2) /* Translation Table Base Control R. */ +#define c2_TTBCR2 (c2_TTBCR + 1) /* Translation Table Base Control R. 2 */ #define c3_DACR (DACR32_EL2 * 2)/* Domain Access Control Register */ #define c5_DFSR (ESR_EL1 * 2) /* Data Fault Status Register */ #define c5_IFSR (IFSR32_EL2 * 2)/* Instruction Fault Status Register */ diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 26c7c25f8a6d..afdf18d694cb 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1925,6 +1925,7 @@ static const struct sys_reg_desc cp15_regs[] = { { Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 }, { Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 }, { Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR }, + { Op1( 0), CRn( 2), CRm( 0), Op2( 3), access_vm_reg, NULL, c2_TTBCR2 }, { Op1( 0), CRn( 3), CRm( 0), Op2( 0), access_vm_reg, NULL, c3_DACR }, { Op1( 0), CRn( 5), CRm( 0), Op2( 0), access_vm_reg, NULL, c5_DFSR }, { Op1( 0), CRn( 5), CRm( 0), Op2( 1), access_vm_reg, NULL, c5_IFSR }, -- 2.28.0

4 years, 7 months

[PATCH 4.4] random32: make prandom_u32() output unpredictable

by Willy Tarreau

From: George Spelvin <lkml(a)sdf.org> commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity(a)gmail.com> Cc: Willy Tarreau <w(a)1wt.eu> Cc: Eric Dumazet <edumazet(a)google.com> Cc: "Jason A. Donenfeld" <Jason(a)zx2c4.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: tytso(a)mit.edu Cc: Florian Westphal <fw(a)strlen.de> Cc: Marc Plumb <lkml.mplumb(a)gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml(a)sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau <w(a)1wt.eu> [wt: backported to 4.4 -- no latent_entropy, drop prandom_reseed_late] Signed-off-by: Willy Tarreau <w(a)1wt.eu> --- drivers/char/random.c | 2 - include/linux/prandom.h | 36 +++- kernel/time/timer.c | 7 - lib/random32.c | 463 +++++++++++++++++++++++++++++------------------- 4 files changed, 317 insertions(+), 191 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 7bb1e42..08d96d5 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -678,7 +678,6 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits) r->initialized = 1; r->entropy_total = 0; if (r == &nonblocking_pool) { - prandom_reseed_late(); process_random_ready_list(); wake_up_all(&urandom_init_wait); pr_notice("random: %s pool is initialized\n", r->name); @@ -923,7 +922,6 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); - this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if ((fast_pool->count < 64) && !time_after(now, fast_pool->last + HZ)) diff --git a/include/linux/prandom.h b/include/linux/prandom.h index aa16e64..cc1e713 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,12 +16,44 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +#if BITS_PER_LONG == 64 +/* + * The core SipHash round function. Each line can be executed in + * parallel given enough CPU resources. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol64(v1, 13), v2 += v3, v3 = rol64(v3, 16), \ + v1 ^= v0, v0 = rol64(v0, 32), v3 ^= v2, \ + v0 += v3, v3 = rol64(v3, 21), v2 += v1, v1 = rol64(v1, 17), \ + v3 ^= v0, v1 ^= v2, v2 = rol64(v2, 32) \ +) + +#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261) +#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573) + +#elif BITS_PER_LONG == 32 +/* + * On 32-bit machines, we use HSipHash, a reduced-width version of SipHash. + * This is weaker, but 32-bit machines are not used for high-traffic + * applications, so there is less output for an attacker to analyze. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol32(v1, 5), v2 += v3, v3 = rol32(v3, 8), \ + v1 ^= v0, v0 = rol32(v0, 16), v3 ^= v2, \ + v0 += v3, v3 = rol32(v3, 7), v2 += v1, v1 = rol32(v1, 13), \ + v3 ^= v0, v1 ^= v2, v2 = rol32(v2, 16) \ +) +#define PRND_K0 0x6c796765 +#define PRND_K1 0x74656462 + +#else +#error Unsupported BITS_PER_LONG +#endif + struct rnd_state { __u32 s1, s2, s3, s4; }; -DECLARE_PER_CPU(struct rnd_state, net_rand_state); - u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 43bee49..6ca409a 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1432,13 +1432,6 @@ void update_process_times(int user_tick) #endif scheduler_tick(); run_posix_cpu_timers(p); - - /* The current CPU might make use of net randoms without receiving IRQs - * to renew them often enough. Let's update the net_rand_state from a - * non-constant value that's not affine to the number of calls to make - * sure it's updated when there's some activity (we don't care in idle). - */ - this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /* diff --git a/lib/random32.c b/lib/random32.c index 8072ccd..17e5780 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -39,16 +39,6 @@ #include <linux/sched.h> #include <asm/unaligned.h> -#ifdef CONFIG_RANDOM32_SELFTEST -static void __init prandom_state_selftest(void); -#else -static inline void prandom_state_selftest(void) -{ -} -#endif - -DEFINE_PER_CPU(struct rnd_state, net_rand_state); - /** * prandom_u32_state - seeded pseudo-random number generator. * @state: pointer to state structure holding seeded state. @@ -69,25 +59,6 @@ u32 prandom_u32_state(struct rnd_state *state) EXPORT_SYMBOL(prandom_u32_state); /** - * prandom_u32 - pseudo random number generator - * - * A 32 bit pseudo-random number is generated using a fast - * algorithm suitable for simulation. This algorithm is NOT - * considered safe for cryptographic use. - */ -u32 prandom_u32(void) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - u32 res; - - res = prandom_u32_state(state); - put_cpu_var(state); - - return res; -} -EXPORT_SYMBOL(prandom_u32); - -/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -118,20 +89,6 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) } EXPORT_SYMBOL(prandom_bytes_state); -/** - * prandom_bytes - get the requested number of pseudo-random bytes - * @buf: where to copy the pseudo-random bytes to - * @bytes: the requested number of bytes - */ -void prandom_bytes(void *buf, size_t bytes) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - - prandom_bytes_state(state, buf, bytes); - put_cpu_var(state); -} -EXPORT_SYMBOL(prandom_bytes); - static void prandom_warmup(struct rnd_state *state) { /* Calling RNG ten times to satisfy recurrence condition */ @@ -147,97 +104,6 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static u32 __extract_hwseed(void) -{ - unsigned int val = 0; - - (void)(arch_get_random_seed_int(&val) || - arch_get_random_int(&val)); - - return val; -} - -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) -{ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ -#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) - state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); - state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); - state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); - state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); -} - -/** - * prandom_seed - add entropy to pseudo random number generator - * @seed: seed value - * - * Add some additional seeding to the prandom pool. - */ -void prandom_seed(u32 entropy) -{ - int i; - /* - * No locking on the CPUs, but then somewhat random results are, well, - * expected. - */ - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - - state->s1 = __seed(state->s1 ^ entropy, 2U); - prandom_warmup(state); - } -} -EXPORT_SYMBOL(prandom_seed); - -/* - * Generate some initially weak seeding values to allow - * to start the prandom_u32() engine. - */ -static int __init prandom_init(void) -{ - int i; - - prandom_state_selftest(); - - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - - prandom_seed_early(state, weak_seed, true); - prandom_warmup(state); - } - - return 0; -} -core_initcall(prandom_init); - -static void __prandom_timer(unsigned long dontcare); - -static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0); - -static void __prandom_timer(unsigned long dontcare) -{ - u32 entropy; - unsigned long expires; - - get_random_bytes(&entropy, sizeof(entropy)); - prandom_seed(entropy); - - /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ - expires = 40 + prandom_u32_max(40); - seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); - - add_timer(&seed_timer); -} - -static void __init __prandom_start_seed_timer(void) -{ - set_timer_slack(&seed_timer, HZ); - seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); - add_timer(&seed_timer); -} - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; @@ -256,51 +122,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) } } -/* - * Generate better values after random number generator - * is fully initialized. - */ -static void __prandom_reseed(bool late) -{ - unsigned long flags; - static bool latch = false; - static DEFINE_SPINLOCK(lock); - - /* Asking for random bytes might result in bytes getting - * moved into the nonblocking pool and thus marking it - * as initialized. In this case we would double back into - * this function and attempt to do a late reseed. - * Ignore the pointless attempt to reseed again if we're - * already waiting for bytes when the nonblocking pool - * got initialized. - */ - - /* only allow initial seeding (late == false) once */ - if (!spin_trylock_irqsave(&lock, flags)) - return; - - if (latch && !late) - goto out; - - latch = true; - prandom_seed_full_state(&net_rand_state); -out: - spin_unlock_irqrestore(&lock, flags); -} - -void prandom_reseed_late(void) -{ - __prandom_reseed(true); -} - -static int __init prandom_reseed(void) -{ - __prandom_reseed(false); - __prandom_start_seed_timer(); - return 0; -} -late_initcall(prandom_reseed); - #ifdef CONFIG_RANDOM32_SELFTEST static struct prandom_test1 { u32 seed; @@ -420,7 +241,28 @@ static struct prandom_test2 { { 407983964U, 921U, 728767059U }, }; -static void __init prandom_state_selftest(void) +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + +static int __init prandom_state_selftest(void) { int i, j, errors = 0, runs = 0; bool error = false; @@ -460,5 +302,266 @@ static void __init prandom_state_selftest(void) pr_warn("prandom: %d/%d self tests failed\n", errors, runs); else pr_info("prandom: %d self tests passed\n", runs); + return 0; } +core_initcall(prandom_state_selftest); #endif + +/* + * The prandom_u32() implementation is now completely separate from the + * prandom_state() functions, which are retained (for now) for compatibility. + * + * Because of (ab)use in the networking code for choosing random TCP/UDP port + * numbers, which open DoS possibilities if guessable, we want something + * stronger than a standard PRNG. But the performance requirements of + * the network code do not allow robust crypto for this application. + * + * So this is a homebrew Junior Spaceman implementation, based on the + * lowest-latency trustworthy crypto primitive available, SipHash. + * (The authors of SipHash have not been consulted about this abuse of + * their work.) + * + * Standard SipHash-2-4 uses 2n+4 rounds to hash n words of input to + * one word of output. This abbreviated version uses 2 rounds per word + * of output. + */ + +struct siprand_state { + unsigned long v0; + unsigned long v1; + unsigned long v2; + unsigned long v3; +}; + +static DEFINE_PER_CPU(struct siprand_state, net_rand_state); + +/* + * This is the core CPRNG function. As "pseudorandom", this is not used + * for truly valuable things, just intended to be a PITA to guess. + * For maximum speed, we do just two SipHash rounds per word. This is + * the same rate as 4 rounds per 64 bits that SipHash normally uses, + * so hopefully it's reasonably secure. + * + * There are two changes from the official SipHash finalization: + * - We omit some constants XORed with v2 in the SipHash spec as irrelevant; + * they are there only to make the output rounds distinct from the input + * rounds, and this application has no input rounds. + * - Rather than returning v0^v1^v2^v3, return v1+v3. + * If you look at the SipHash round, the last operation on v3 is + * "v3 ^= v0", so "v0 ^ v3" just undoes that, a waste of time. + * Likewise "v1 ^= v2". (The rotate of v2 makes a difference, but + * it still cancels out half of the bits in v2 for no benefit.) + * Second, since the last combining operation was xor, continue the + * pattern of alternating xor/add for a tiny bit of extra non-linearity. + */ +static inline u32 siprand_u32(struct siprand_state *s) +{ + unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; + return v1 + v3; +} + + +/** + * prandom_u32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 prandom_u32(void) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u32 res = siprand_u32(state); + + put_cpu_ptr(&net_rand_state); + return res; +} +EXPORT_SYMBOL(prandom_u32); + +/** + * prandom_bytes - get the requested number of pseudo-random bytes + * @buf: where to copy the pseudo-random bytes to + * @bytes: the requested number of bytes + */ +void prandom_bytes(void *buf, size_t bytes) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(siprand_u32(state), (u32 *)ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } + + if (bytes > 0) { + u32 rem = siprand_u32(state); + + do { + *ptr++ = (u8)rem; + rem >>= BITS_PER_BYTE; + } while (--bytes > 0); + } + put_cpu_ptr(&net_rand_state); +} +EXPORT_SYMBOL(prandom_bytes); + +/** + * prandom_seed - add entropy to pseudo random number generator + * @entropy: entropy value + * + * Add some additional seed material to the prandom pool. + * The "entropy" is actually our IP address (the only caller is + * the network code), not for unpredictability, but to ensure that + * different machines are initialized differently. + */ +void prandom_seed(u32 entropy) +{ + int i; + + add_device_randomness(&entropy, sizeof(entropy)); + + for_each_possible_cpu(i) { + struct siprand_state *state = per_cpu_ptr(&net_rand_state, i); + unsigned long v0 = state->v0, v1 = state->v1; + unsigned long v2 = state->v2, v3 = state->v3; + + do { + v3 ^= entropy; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= entropy; + } while (unlikely(!v0 || !v1 || !v2 || !v3)); + + WRITE_ONCE(state->v0, v0); + WRITE_ONCE(state->v1, v1); + WRITE_ONCE(state->v2, v2); + WRITE_ONCE(state->v3, v3); + } +} +EXPORT_SYMBOL(prandom_seed); + +/* + * Generate some initially weak seeding values to allow + * the prandom_u32() engine to be started. + */ +static int __init prandom_init_early(void) +{ + int i; + unsigned long v0, v1, v2, v3; + + if (!arch_get_random_long(&v0)) + v0 = jiffies; + if (!arch_get_random_long(&v1)) + v1 = random_get_entropy(); + v2 = v0 ^ PRND_K0; + v3 = v1 ^ PRND_K1; + + for_each_possible_cpu(i) { + struct siprand_state *state; + + v3 ^= i; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= i; + + state = per_cpu_ptr(&net_rand_state, i); + state->v0 = v0; state->v1 = v1; + state->v2 = v2; state->v3 = v3; + } + + return 0; +} +core_initcall(prandom_init_early); + + +/* Stronger reseeding when available, and periodically thereafter. */ +static void prandom_reseed(unsigned long dontcare); + +static DEFINE_TIMER(seed_timer, prandom_reseed, 0, 0); + +static void prandom_reseed(unsigned long dontcare) +{ + unsigned long expires; + int i; + + /* + * Reinitialize each CPU's PRNG with 128 bits of key. + * No locking on the CPUs, but then somewhat random results are, + * well, expected. + */ + for_each_possible_cpu(i) { + struct siprand_state *state; + unsigned long v0 = get_random_long(), v2 = v0 ^ PRND_K0; + unsigned long v1 = get_random_long(), v3 = v1 ^ PRND_K1; +#if BITS_PER_LONG == 32 + int j; + + /* + * On 32-bit machines, hash in two extra words to + * approximate 128-bit key length. Not that the hash + * has that much security, but this prevents a trivial + * 64-bit brute force. + */ + for (j = 0; j < 2; j++) { + unsigned long m = get_random_long(); + + v3 ^= m; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= m; + } +#endif + /* + * Probably impossible in practice, but there is a + * theoretical risk that a race between this reseeding + * and the target CPU writing its state back could + * create the all-zero SipHash fixed point. + * + * To ensure that never happens, ensure the state + * we write contains no zero words. + */ + state = per_cpu_ptr(&net_rand_state, i); + WRITE_ONCE(state->v0, v0 ? v0 : -1ul); + WRITE_ONCE(state->v1, v1 ? v1 : -1ul); + WRITE_ONCE(state->v2, v2 ? v2 : -1ul); + WRITE_ONCE(state->v3, v3 ? v3 : -1ul); + } + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = round_jiffies(jiffies + 40 * HZ + prandom_u32_max(40 * HZ)); + mod_timer(&seed_timer, expires); +} + +/* + * The random ready callback can be called from almost any interrupt. + * To avoid worrying about whether it's safe to delay that interrupt + * long enough to seed all CPUs, just schedule an immediate timer event. + */ +static void prandom_timer_start(struct random_ready_callback *unused) +{ + mod_timer(&seed_timer, jiffies); +} + +/* + * Start periodic full reseeding as soon as strong + * random numbers are available. + */ +static int __init prandom_init_late(void) +{ + static struct random_ready_callback random_ready = { + .func = prandom_timer_start + }; + int ret = add_random_ready_callback(&random_ready); + + if (ret == -EALREADY) { + prandom_timer_start(&random_ready); + ret = 0; + } + return ret; +} +late_initcall(prandom_init_late); -- 2.9.0

4 years, 7 months

[PATCH 4.9] random32: make prandom_u32() output unpredictable

by Willy Tarreau

From: George Spelvin <lkml(a)sdf.org> commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity(a)gmail.com> Cc: Willy Tarreau <w(a)1wt.eu> Cc: Eric Dumazet <edumazet(a)google.com> Cc: "Jason A. Donenfeld" <Jason(a)zx2c4.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: tytso(a)mit.edu Cc: Florian Westphal <fw(a)strlen.de> Cc: Marc Plumb <lkml.mplumb(a)gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml(a)sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau <w(a)1wt.eu> [wt: backported to 4.9 -- various context adjustments; timer API change] Signed-off-by: Willy Tarreau <w(a)1wt.eu> --- drivers/char/random.c | 1 - include/linux/prandom.h | 36 +++- kernel/time/timer.c | 7 - lib/random32.c | 462 +++++++++++++++++++++++++++++------------------- 4 files changed, 317 insertions(+), 189 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index c417aa1..4cbc731 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1211,7 +1211,6 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); - this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && diff --git a/include/linux/prandom.h b/include/linux/prandom.h index aa16e64..cc1e713 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,12 +16,44 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +#if BITS_PER_LONG == 64 +/* + * The core SipHash round function. Each line can be executed in + * parallel given enough CPU resources. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol64(v1, 13), v2 += v3, v3 = rol64(v3, 16), \ + v1 ^= v0, v0 = rol64(v0, 32), v3 ^= v2, \ + v0 += v3, v3 = rol64(v3, 21), v2 += v1, v1 = rol64(v1, 17), \ + v3 ^= v0, v1 ^= v2, v2 = rol64(v2, 32) \ +) + +#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261) +#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573) + +#elif BITS_PER_LONG == 32 +/* + * On 32-bit machines, we use HSipHash, a reduced-width version of SipHash. + * This is weaker, but 32-bit machines are not used for high-traffic + * applications, so there is less output for an attacker to analyze. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol32(v1, 5), v2 += v3, v3 = rol32(v3, 8), \ + v1 ^= v0, v0 = rol32(v0, 16), v3 ^= v2, \ + v0 += v3, v3 = rol32(v3, 7), v2 += v1, v1 = rol32(v1, 13), \ + v3 ^= v0, v1 ^= v2, v2 = rol32(v2, 16) \ +) +#define PRND_K0 0x6c796765 +#define PRND_K1 0x74656462 + +#else +#error Unsupported BITS_PER_LONG +#endif + struct rnd_state { __u32 s1, s2, s3, s4; }; -DECLARE_PER_CPU(struct rnd_state, net_rand_state); - u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index d2e4698..c9325a1 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1636,13 +1636,6 @@ void update_process_times(int user_tick) #endif scheduler_tick(); run_posix_cpu_timers(p); - - /* The current CPU might make use of net randoms without receiving IRQs - * to renew them often enough. Let's update the net_rand_state from a - * non-constant value that's not affine to the number of calls to make - * sure it's updated when there's some activity (we don't care in idle). - */ - this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /** diff --git a/lib/random32.c b/lib/random32.c index d5c3137..3c5b67b 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -39,16 +39,6 @@ #include <linux/sched.h> #include <asm/unaligned.h> -#ifdef CONFIG_RANDOM32_SELFTEST -static void __init prandom_state_selftest(void); -#else -static inline void prandom_state_selftest(void) -{ -} -#endif - -DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; - /** * prandom_u32_state - seeded pseudo-random number generator. * @state: pointer to state structure holding seeded state. @@ -69,25 +59,6 @@ u32 prandom_u32_state(struct rnd_state *state) EXPORT_SYMBOL(prandom_u32_state); /** - * prandom_u32 - pseudo random number generator - * - * A 32 bit pseudo-random number is generated using a fast - * algorithm suitable for simulation. This algorithm is NOT - * considered safe for cryptographic use. - */ -u32 prandom_u32(void) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - u32 res; - - res = prandom_u32_state(state); - put_cpu_var(net_rand_state); - - return res; -} -EXPORT_SYMBOL(prandom_u32); - -/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -118,20 +89,6 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) } EXPORT_SYMBOL(prandom_bytes_state); -/** - * prandom_bytes - get the requested number of pseudo-random bytes - * @buf: where to copy the pseudo-random bytes to - * @bytes: the requested number of bytes - */ -void prandom_bytes(void *buf, size_t bytes) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - - prandom_bytes_state(state, buf, bytes); - put_cpu_var(net_rand_state); -} -EXPORT_SYMBOL(prandom_bytes); - static void prandom_warmup(struct rnd_state *state) { /* Calling RNG ten times to satisfy recurrence condition */ @@ -147,96 +104,6 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static u32 __extract_hwseed(void) -{ - unsigned int val = 0; - - (void)(arch_get_random_seed_int(&val) || - arch_get_random_int(&val)); - - return val; -} - -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) -{ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ -#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) - state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); - state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); - state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); - state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); -} - -/** - * prandom_seed - add entropy to pseudo random number generator - * @seed: seed value - * - * Add some additional seeding to the prandom pool. - */ -void prandom_seed(u32 entropy) -{ - int i; - /* - * No locking on the CPUs, but then somewhat random results are, well, - * expected. - */ - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - - state->s1 = __seed(state->s1 ^ entropy, 2U); - prandom_warmup(state); - } -} -EXPORT_SYMBOL(prandom_seed); - -/* - * Generate some initially weak seeding values to allow - * to start the prandom_u32() engine. - */ -static int __init prandom_init(void) -{ - int i; - - prandom_state_selftest(); - - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - - prandom_seed_early(state, weak_seed, true); - prandom_warmup(state); - } - - return 0; -} -core_initcall(prandom_init); - -static void __prandom_timer(unsigned long dontcare); - -static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0); - -static void __prandom_timer(unsigned long dontcare) -{ - u32 entropy; - unsigned long expires; - - get_random_bytes(&entropy, sizeof(entropy)); - prandom_seed(entropy); - - /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ - expires = 40 + prandom_u32_max(40); - seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); - - add_timer(&seed_timer); -} - -static void __init __prandom_start_seed_timer(void) -{ - seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); - add_timer(&seed_timer); -} - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; @@ -256,51 +123,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) } EXPORT_SYMBOL(prandom_seed_full_state); -/* - * Generate better values after random number generator - * is fully initialized. - */ -static void __prandom_reseed(bool late) -{ - unsigned long flags; - static bool latch = false; - static DEFINE_SPINLOCK(lock); - - /* Asking for random bytes might result in bytes getting - * moved into the nonblocking pool and thus marking it - * as initialized. In this case we would double back into - * this function and attempt to do a late reseed. - * Ignore the pointless attempt to reseed again if we're - * already waiting for bytes when the nonblocking pool - * got initialized. - */ - - /* only allow initial seeding (late == false) once */ - if (!spin_trylock_irqsave(&lock, flags)) - return; - - if (latch && !late) - goto out; - - latch = true; - prandom_seed_full_state(&net_rand_state); -out: - spin_unlock_irqrestore(&lock, flags); -} - -void prandom_reseed_late(void) -{ - __prandom_reseed(true); -} - -static int __init prandom_reseed(void) -{ - __prandom_reseed(false); - __prandom_start_seed_timer(); - return 0; -} -late_initcall(prandom_reseed); - #ifdef CONFIG_RANDOM32_SELFTEST static struct prandom_test1 { u32 seed; @@ -420,7 +242,28 @@ static struct prandom_test2 { { 407983964U, 921U, 728767059U }, }; -static void __init prandom_state_selftest(void) +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + +static int __init prandom_state_selftest(void) { int i, j, errors = 0, runs = 0; bool error = false; @@ -460,5 +303,266 @@ static void __init prandom_state_selftest(void) pr_warn("prandom: %d/%d self tests failed\n", errors, runs); else pr_info("prandom: %d self tests passed\n", runs); + return 0; } +core_initcall(prandom_state_selftest); #endif + +/* + * The prandom_u32() implementation is now completely separate from the + * prandom_state() functions, which are retained (for now) for compatibility. + * + * Because of (ab)use in the networking code for choosing random TCP/UDP port + * numbers, which open DoS possibilities if guessable, we want something + * stronger than a standard PRNG. But the performance requirements of + * the network code do not allow robust crypto for this application. + * + * So this is a homebrew Junior Spaceman implementation, based on the + * lowest-latency trustworthy crypto primitive available, SipHash. + * (The authors of SipHash have not been consulted about this abuse of + * their work.) + * + * Standard SipHash-2-4 uses 2n+4 rounds to hash n words of input to + * one word of output. This abbreviated version uses 2 rounds per word + * of output. + */ + +struct siprand_state { + unsigned long v0; + unsigned long v1; + unsigned long v2; + unsigned long v3; +}; + +static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; + +/* + * This is the core CPRNG function. As "pseudorandom", this is not used + * for truly valuable things, just intended to be a PITA to guess. + * For maximum speed, we do just two SipHash rounds per word. This is + * the same rate as 4 rounds per 64 bits that SipHash normally uses, + * so hopefully it's reasonably secure. + * + * There are two changes from the official SipHash finalization: + * - We omit some constants XORed with v2 in the SipHash spec as irrelevant; + * they are there only to make the output rounds distinct from the input + * rounds, and this application has no input rounds. + * - Rather than returning v0^v1^v2^v3, return v1+v3. + * If you look at the SipHash round, the last operation on v3 is + * "v3 ^= v0", so "v0 ^ v3" just undoes that, a waste of time. + * Likewise "v1 ^= v2". (The rotate of v2 makes a difference, but + * it still cancels out half of the bits in v2 for no benefit.) + * Second, since the last combining operation was xor, continue the + * pattern of alternating xor/add for a tiny bit of extra non-linearity. + */ +static inline u32 siprand_u32(struct siprand_state *s) +{ + unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; + return v1 + v3; +} + + +/** + * prandom_u32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 prandom_u32(void) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u32 res = siprand_u32(state); + + put_cpu_ptr(&net_rand_state); + return res; +} +EXPORT_SYMBOL(prandom_u32); + +/** + * prandom_bytes - get the requested number of pseudo-random bytes + * @buf: where to copy the pseudo-random bytes to + * @bytes: the requested number of bytes + */ +void prandom_bytes(void *buf, size_t bytes) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(siprand_u32(state), (u32 *)ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } + + if (bytes > 0) { + u32 rem = siprand_u32(state); + + do { + *ptr++ = (u8)rem; + rem >>= BITS_PER_BYTE; + } while (--bytes > 0); + } + put_cpu_ptr(&net_rand_state); +} +EXPORT_SYMBOL(prandom_bytes); + +/** + * prandom_seed - add entropy to pseudo random number generator + * @entropy: entropy value + * + * Add some additional seed material to the prandom pool. + * The "entropy" is actually our IP address (the only caller is + * the network code), not for unpredictability, but to ensure that + * different machines are initialized differently. + */ +void prandom_seed(u32 entropy) +{ + int i; + + add_device_randomness(&entropy, sizeof(entropy)); + + for_each_possible_cpu(i) { + struct siprand_state *state = per_cpu_ptr(&net_rand_state, i); + unsigned long v0 = state->v0, v1 = state->v1; + unsigned long v2 = state->v2, v3 = state->v3; + + do { + v3 ^= entropy; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= entropy; + } while (unlikely(!v0 || !v1 || !v2 || !v3)); + + WRITE_ONCE(state->v0, v0); + WRITE_ONCE(state->v1, v1); + WRITE_ONCE(state->v2, v2); + WRITE_ONCE(state->v3, v3); + } +} +EXPORT_SYMBOL(prandom_seed); + +/* + * Generate some initially weak seeding values to allow + * the prandom_u32() engine to be started. + */ +static int __init prandom_init_early(void) +{ + int i; + unsigned long v0, v1, v2, v3; + + if (!arch_get_random_long(&v0)) + v0 = jiffies; + if (!arch_get_random_long(&v1)) + v1 = random_get_entropy(); + v2 = v0 ^ PRND_K0; + v3 = v1 ^ PRND_K1; + + for_each_possible_cpu(i) { + struct siprand_state *state; + + v3 ^= i; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= i; + + state = per_cpu_ptr(&net_rand_state, i); + state->v0 = v0; state->v1 = v1; + state->v2 = v2; state->v3 = v3; + } + + return 0; +} +core_initcall(prandom_init_early); + + +/* Stronger reseeding when available, and periodically thereafter. */ +static void prandom_reseed(unsigned long dontcare); + +static DEFINE_TIMER(seed_timer, prandom_reseed, 0, 0); + +static void prandom_reseed(unsigned long dontcare) +{ + unsigned long expires; + int i; + + /* + * Reinitialize each CPU's PRNG with 128 bits of key. + * No locking on the CPUs, but then somewhat random results are, + * well, expected. + */ + for_each_possible_cpu(i) { + struct siprand_state *state; + unsigned long v0 = get_random_long(), v2 = v0 ^ PRND_K0; + unsigned long v1 = get_random_long(), v3 = v1 ^ PRND_K1; +#if BITS_PER_LONG == 32 + int j; + + /* + * On 32-bit machines, hash in two extra words to + * approximate 128-bit key length. Not that the hash + * has that much security, but this prevents a trivial + * 64-bit brute force. + */ + for (j = 0; j < 2; j++) { + unsigned long m = get_random_long(); + + v3 ^= m; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= m; + } +#endif + /* + * Probably impossible in practice, but there is a + * theoretical risk that a race between this reseeding + * and the target CPU writing its state back could + * create the all-zero SipHash fixed point. + * + * To ensure that never happens, ensure the state + * we write contains no zero words. + */ + state = per_cpu_ptr(&net_rand_state, i); + WRITE_ONCE(state->v0, v0 ? v0 : -1ul); + WRITE_ONCE(state->v1, v1 ? v1 : -1ul); + WRITE_ONCE(state->v2, v2 ? v2 : -1ul); + WRITE_ONCE(state->v3, v3 ? v3 : -1ul); + } + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = round_jiffies(jiffies + 40 * HZ + prandom_u32_max(40 * HZ)); + mod_timer(&seed_timer, expires); +} + +/* + * The random ready callback can be called from almost any interrupt. + * To avoid worrying about whether it's safe to delay that interrupt + * long enough to seed all CPUs, just schedule an immediate timer event. + */ +static void prandom_timer_start(struct random_ready_callback *unused) +{ + mod_timer(&seed_timer, jiffies); +} + +/* + * Start periodic full reseeding as soon as strong + * random numbers are available. + */ +static int __init prandom_init_late(void) +{ + static struct random_ready_callback random_ready = { + .func = prandom_timer_start + }; + int ret = add_random_ready_callback(&random_ready); + + if (ret == -EALREADY) { + prandom_timer_start(&random_ready); + ret = 0; + } + return ret; +} +late_initcall(prandom_init_late); -- 2.9.0

4 years, 7 months

[PATCH 4.14] random32: make prandom_u32() output unpredictable

by Willy Tarreau

From: George Spelvin <lkml(a)sdf.org> commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity(a)gmail.com> Cc: Willy Tarreau <w(a)1wt.eu> Cc: Eric Dumazet <edumazet(a)google.com> Cc: "Jason A. Donenfeld" <Jason(a)zx2c4.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: tytso(a)mit.edu Cc: Florian Westphal <fw(a)strlen.de> Cc: Marc Plumb <lkml.mplumb(a)gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml(a)sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau <w(a)1wt.eu> [wt: backported to 4.14 -- various context adjustments; timer API change] Signed-off-by: Willy Tarreau <w(a)1wt.eu> --- drivers/char/random.c | 1 - include/linux/prandom.h | 36 +++- kernel/time/timer.c | 7 - lib/random32.c | 462 +++++++++++++++++++++++++++++------------------- 4 files changed, 317 insertions(+), 189 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index b202f66..868d262 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1246,7 +1246,6 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); - this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && diff --git a/include/linux/prandom.h b/include/linux/prandom.h index aa16e64..cc1e713 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,12 +16,44 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +#if BITS_PER_LONG == 64 +/* + * The core SipHash round function. Each line can be executed in + * parallel given enough CPU resources. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol64(v1, 13), v2 += v3, v3 = rol64(v3, 16), \ + v1 ^= v0, v0 = rol64(v0, 32), v3 ^= v2, \ + v0 += v3, v3 = rol64(v3, 21), v2 += v1, v1 = rol64(v1, 17), \ + v3 ^= v0, v1 ^= v2, v2 = rol64(v2, 32) \ +) + +#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261) +#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573) + +#elif BITS_PER_LONG == 32 +/* + * On 32-bit machines, we use HSipHash, a reduced-width version of SipHash. + * This is weaker, but 32-bit machines are not used for high-traffic + * applications, so there is less output for an attacker to analyze. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol32(v1, 5), v2 += v3, v3 = rol32(v3, 8), \ + v1 ^= v0, v0 = rol32(v0, 16), v3 ^= v2, \ + v0 += v3, v3 = rol32(v3, 7), v2 += v1, v1 = rol32(v1, 13), \ + v3 ^= v0, v1 ^= v2, v2 = rol32(v2, 16) \ +) +#define PRND_K0 0x6c796765 +#define PRND_K1 0x74656462 + +#else +#error Unsupported BITS_PER_LONG +#endif + struct rnd_state { __u32 s1, s2, s3, s4; }; -DECLARE_PER_CPU(struct rnd_state, net_rand_state); - u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index d4bc272..99f885d 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1596,13 +1596,6 @@ void update_process_times(int user_tick) scheduler_tick(); if (IS_ENABLED(CONFIG_POSIX_TIMERS)) run_posix_cpu_timers(p); - - /* The current CPU might make use of net randoms without receiving IRQs - * to renew them often enough. Let's update the net_rand_state from a - * non-constant value that's not affine to the number of calls to make - * sure it's updated when there's some activity (we don't care in idle). - */ - this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /** diff --git a/lib/random32.c b/lib/random32.c index eb54663..f5e967f 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -40,16 +40,6 @@ #include <linux/sched.h> #include <asm/unaligned.h> -#ifdef CONFIG_RANDOM32_SELFTEST -static void __init prandom_state_selftest(void); -#else -static inline void prandom_state_selftest(void) -{ -} -#endif - -DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; - /** * prandom_u32_state - seeded pseudo-random number generator. * @state: pointer to state structure holding seeded state. @@ -70,25 +60,6 @@ u32 prandom_u32_state(struct rnd_state *state) EXPORT_SYMBOL(prandom_u32_state); /** - * prandom_u32 - pseudo random number generator - * - * A 32 bit pseudo-random number is generated using a fast - * algorithm suitable for simulation. This algorithm is NOT - * considered safe for cryptographic use. - */ -u32 prandom_u32(void) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - u32 res; - - res = prandom_u32_state(state); - put_cpu_var(net_rand_state); - - return res; -} -EXPORT_SYMBOL(prandom_u32); - -/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -119,20 +90,6 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) } EXPORT_SYMBOL(prandom_bytes_state); -/** - * prandom_bytes - get the requested number of pseudo-random bytes - * @buf: where to copy the pseudo-random bytes to - * @bytes: the requested number of bytes - */ -void prandom_bytes(void *buf, size_t bytes) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - - prandom_bytes_state(state, buf, bytes); - put_cpu_var(net_rand_state); -} -EXPORT_SYMBOL(prandom_bytes); - static void prandom_warmup(struct rnd_state *state) { /* Calling RNG ten times to satisfy recurrence condition */ @@ -148,96 +105,6 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static u32 __extract_hwseed(void) -{ - unsigned int val = 0; - - (void)(arch_get_random_seed_int(&val) || - arch_get_random_int(&val)); - - return val; -} - -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) -{ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ -#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) - state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); - state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); - state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); - state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); -} - -/** - * prandom_seed - add entropy to pseudo random number generator - * @seed: seed value - * - * Add some additional seeding to the prandom pool. - */ -void prandom_seed(u32 entropy) -{ - int i; - /* - * No locking on the CPUs, but then somewhat random results are, well, - * expected. - */ - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - - state->s1 = __seed(state->s1 ^ entropy, 2U); - prandom_warmup(state); - } -} -EXPORT_SYMBOL(prandom_seed); - -/* - * Generate some initially weak seeding values to allow - * to start the prandom_u32() engine. - */ -static int __init prandom_init(void) -{ - int i; - - prandom_state_selftest(); - - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - - prandom_seed_early(state, weak_seed, true); - prandom_warmup(state); - } - - return 0; -} -core_initcall(prandom_init); - -static void __prandom_timer(unsigned long dontcare); - -static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0); - -static void __prandom_timer(unsigned long dontcare) -{ - u32 entropy; - unsigned long expires; - - get_random_bytes(&entropy, sizeof(entropy)); - prandom_seed(entropy); - - /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ - expires = 40 + prandom_u32_max(40); - seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); - - add_timer(&seed_timer); -} - -static void __init __prandom_start_seed_timer(void) -{ - seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); - add_timer(&seed_timer); -} - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; @@ -257,51 +124,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) } EXPORT_SYMBOL(prandom_seed_full_state); -/* - * Generate better values after random number generator - * is fully initialized. - */ -static void __prandom_reseed(bool late) -{ - unsigned long flags; - static bool latch = false; - static DEFINE_SPINLOCK(lock); - - /* Asking for random bytes might result in bytes getting - * moved into the nonblocking pool and thus marking it - * as initialized. In this case we would double back into - * this function and attempt to do a late reseed. - * Ignore the pointless attempt to reseed again if we're - * already waiting for bytes when the nonblocking pool - * got initialized. - */ - - /* only allow initial seeding (late == false) once */ - if (!spin_trylock_irqsave(&lock, flags)) - return; - - if (latch && !late) - goto out; - - latch = true; - prandom_seed_full_state(&net_rand_state); -out: - spin_unlock_irqrestore(&lock, flags); -} - -void prandom_reseed_late(void) -{ - __prandom_reseed(true); -} - -static int __init prandom_reseed(void) -{ - __prandom_reseed(false); - __prandom_start_seed_timer(); - return 0; -} -late_initcall(prandom_reseed); - #ifdef CONFIG_RANDOM32_SELFTEST static struct prandom_test1 { u32 seed; @@ -421,7 +243,28 @@ static struct prandom_test2 { { 407983964U, 921U, 728767059U }, }; -static void __init prandom_state_selftest(void) +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + +static int __init prandom_state_selftest(void) { int i, j, errors = 0, runs = 0; bool error = false; @@ -461,5 +304,266 @@ static void __init prandom_state_selftest(void) pr_warn("prandom: %d/%d self tests failed\n", errors, runs); else pr_info("prandom: %d self tests passed\n", runs); + return 0; } +core_initcall(prandom_state_selftest); #endif + +/* + * The prandom_u32() implementation is now completely separate from the + * prandom_state() functions, which are retained (for now) for compatibility. + * + * Because of (ab)use in the networking code for choosing random TCP/UDP port + * numbers, which open DoS possibilities if guessable, we want something + * stronger than a standard PRNG. But the performance requirements of + * the network code do not allow robust crypto for this application. + * + * So this is a homebrew Junior Spaceman implementation, based on the + * lowest-latency trustworthy crypto primitive available, SipHash. + * (The authors of SipHash have not been consulted about this abuse of + * their work.) + * + * Standard SipHash-2-4 uses 2n+4 rounds to hash n words of input to + * one word of output. This abbreviated version uses 2 rounds per word + * of output. + */ + +struct siprand_state { + unsigned long v0; + unsigned long v1; + unsigned long v2; + unsigned long v3; +}; + +static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; + +/* + * This is the core CPRNG function. As "pseudorandom", this is not used + * for truly valuable things, just intended to be a PITA to guess. + * For maximum speed, we do just two SipHash rounds per word. This is + * the same rate as 4 rounds per 64 bits that SipHash normally uses, + * so hopefully it's reasonably secure. + * + * There are two changes from the official SipHash finalization: + * - We omit some constants XORed with v2 in the SipHash spec as irrelevant; + * they are there only to make the output rounds distinct from the input + * rounds, and this application has no input rounds. + * - Rather than returning v0^v1^v2^v3, return v1+v3. + * If you look at the SipHash round, the last operation on v3 is + * "v3 ^= v0", so "v0 ^ v3" just undoes that, a waste of time. + * Likewise "v1 ^= v2". (The rotate of v2 makes a difference, but + * it still cancels out half of the bits in v2 for no benefit.) + * Second, since the last combining operation was xor, continue the + * pattern of alternating xor/add for a tiny bit of extra non-linearity. + */ +static inline u32 siprand_u32(struct siprand_state *s) +{ + unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; + return v1 + v3; +} + + +/** + * prandom_u32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 prandom_u32(void) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u32 res = siprand_u32(state); + + put_cpu_ptr(&net_rand_state); + return res; +} +EXPORT_SYMBOL(prandom_u32); + +/** + * prandom_bytes - get the requested number of pseudo-random bytes + * @buf: where to copy the pseudo-random bytes to + * @bytes: the requested number of bytes + */ +void prandom_bytes(void *buf, size_t bytes) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(siprand_u32(state), (u32 *)ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } + + if (bytes > 0) { + u32 rem = siprand_u32(state); + + do { + *ptr++ = (u8)rem; + rem >>= BITS_PER_BYTE; + } while (--bytes > 0); + } + put_cpu_ptr(&net_rand_state); +} +EXPORT_SYMBOL(prandom_bytes); + +/** + * prandom_seed - add entropy to pseudo random number generator + * @entropy: entropy value + * + * Add some additional seed material to the prandom pool. + * The "entropy" is actually our IP address (the only caller is + * the network code), not for unpredictability, but to ensure that + * different machines are initialized differently. + */ +void prandom_seed(u32 entropy) +{ + int i; + + add_device_randomness(&entropy, sizeof(entropy)); + + for_each_possible_cpu(i) { + struct siprand_state *state = per_cpu_ptr(&net_rand_state, i); + unsigned long v0 = state->v0, v1 = state->v1; + unsigned long v2 = state->v2, v3 = state->v3; + + do { + v3 ^= entropy; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= entropy; + } while (unlikely(!v0 || !v1 || !v2 || !v3)); + + WRITE_ONCE(state->v0, v0); + WRITE_ONCE(state->v1, v1); + WRITE_ONCE(state->v2, v2); + WRITE_ONCE(state->v3, v3); + } +} +EXPORT_SYMBOL(prandom_seed); + +/* + * Generate some initially weak seeding values to allow + * the prandom_u32() engine to be started. + */ +static int __init prandom_init_early(void) +{ + int i; + unsigned long v0, v1, v2, v3; + + if (!arch_get_random_long(&v0)) + v0 = jiffies; + if (!arch_get_random_long(&v1)) + v1 = random_get_entropy(); + v2 = v0 ^ PRND_K0; + v3 = v1 ^ PRND_K1; + + for_each_possible_cpu(i) { + struct siprand_state *state; + + v3 ^= i; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= i; + + state = per_cpu_ptr(&net_rand_state, i); + state->v0 = v0; state->v1 = v1; + state->v2 = v2; state->v3 = v3; + } + + return 0; +} +core_initcall(prandom_init_early); + + +/* Stronger reseeding when available, and periodically thereafter. */ +static void prandom_reseed(unsigned long dontcare); + +static DEFINE_TIMER(seed_timer, prandom_reseed, 0, 0); + +static void prandom_reseed(unsigned long dontcare) +{ + unsigned long expires; + int i; + + /* + * Reinitialize each CPU's PRNG with 128 bits of key. + * No locking on the CPUs, but then somewhat random results are, + * well, expected. + */ + for_each_possible_cpu(i) { + struct siprand_state *state; + unsigned long v0 = get_random_long(), v2 = v0 ^ PRND_K0; + unsigned long v1 = get_random_long(), v3 = v1 ^ PRND_K1; +#if BITS_PER_LONG == 32 + int j; + + /* + * On 32-bit machines, hash in two extra words to + * approximate 128-bit key length. Not that the hash + * has that much security, but this prevents a trivial + * 64-bit brute force. + */ + for (j = 0; j < 2; j++) { + unsigned long m = get_random_long(); + + v3 ^= m; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= m; + } +#endif + /* + * Probably impossible in practice, but there is a + * theoretical risk that a race between this reseeding + * and the target CPU writing its state back could + * create the all-zero SipHash fixed point. + * + * To ensure that never happens, ensure the state + * we write contains no zero words. + */ + state = per_cpu_ptr(&net_rand_state, i); + WRITE_ONCE(state->v0, v0 ? v0 : -1ul); + WRITE_ONCE(state->v1, v1 ? v1 : -1ul); + WRITE_ONCE(state->v2, v2 ? v2 : -1ul); + WRITE_ONCE(state->v3, v3 ? v3 : -1ul); + } + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = round_jiffies(jiffies + 40 * HZ + prandom_u32_max(40 * HZ)); + mod_timer(&seed_timer, expires); +} + +/* + * The random ready callback can be called from almost any interrupt. + * To avoid worrying about whether it's safe to delay that interrupt + * long enough to seed all CPUs, just schedule an immediate timer event. + */ +static void prandom_timer_start(struct random_ready_callback *unused) +{ + mod_timer(&seed_timer, jiffies); +} + +/* + * Start periodic full reseeding as soon as strong + * random numbers are available. + */ +static int __init prandom_init_late(void) +{ + static struct random_ready_callback random_ready = { + .func = prandom_timer_start + }; + int ret = add_random_ready_callback(&random_ready); + + if (ret == -EALREADY) { + prandom_timer_start(&random_ready); + ret = 0; + } + return ret; +} +late_initcall(prandom_init_late); -- 2.9.0

4 years, 7 months

[PATCH 4.19] random32: make prandom_u32() output unpredictable

by Willy Tarreau

From: George Spelvin <lkml(a)sdf.org> commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity(a)gmail.com> Cc: Willy Tarreau <w(a)1wt.eu> Cc: Eric Dumazet <edumazet(a)google.com> Cc: "Jason A. Donenfeld" <Jason(a)zx2c4.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: tytso(a)mit.edu Cc: Florian Westphal <fw(a)strlen.de> Cc: Marc Plumb <lkml.mplumb(a)gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml(a)sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau <w(a)1wt.eu> [wt: backported to 4.19 -- various context adjustments] Signed-off-by: Willy Tarreau <w(a)1wt.eu> --- drivers/char/random.c | 1 - include/linux/prandom.h | 36 +++- kernel/time/timer.c | 7 - lib/random32.c | 462 +++++++++++++++++++++++++++++------------------- 4 files changed, 317 insertions(+), 189 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 80dedec..98925d4 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1257,7 +1257,6 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); - this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && diff --git a/include/linux/prandom.h b/include/linux/prandom.h index aa16e64..cc1e713 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,12 +16,44 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +#if BITS_PER_LONG == 64 +/* + * The core SipHash round function. Each line can be executed in + * parallel given enough CPU resources. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol64(v1, 13), v2 += v3, v3 = rol64(v3, 16), \ + v1 ^= v0, v0 = rol64(v0, 32), v3 ^= v2, \ + v0 += v3, v3 = rol64(v3, 21), v2 += v1, v1 = rol64(v1, 17), \ + v3 ^= v0, v1 ^= v2, v2 = rol64(v2, 32) \ +) + +#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261) +#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573) + +#elif BITS_PER_LONG == 32 +/* + * On 32-bit machines, we use HSipHash, a reduced-width version of SipHash. + * This is weaker, but 32-bit machines are not used for high-traffic + * applications, so there is less output for an attacker to analyze. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol32(v1, 5), v2 += v3, v3 = rol32(v3, 8), \ + v1 ^= v0, v0 = rol32(v0, 16), v3 ^= v2, \ + v0 += v3, v3 = rol32(v3, 7), v2 += v1, v1 = rol32(v1, 13), \ + v3 ^= v0, v1 ^= v2, v2 = rol32(v2, 16) \ +) +#define PRND_K0 0x6c796765 +#define PRND_K1 0x74656462 + +#else +#error Unsupported BITS_PER_LONG +#endif + struct rnd_state { __u32 s1, s2, s3, s4; }; -DECLARE_PER_CPU(struct rnd_state, net_rand_state); - u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 61e41ea..a6e88d9 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1655,13 +1655,6 @@ void update_process_times(int user_tick) scheduler_tick(); if (IS_ENABLED(CONFIG_POSIX_TIMERS)) run_posix_cpu_timers(p); - - /* The current CPU might make use of net randoms without receiving IRQs - * to renew them often enough. Let's update the net_rand_state from a - * non-constant value that's not affine to the number of calls to make - * sure it's updated when there's some activity (we don't care in idle). - */ - this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /** diff --git a/lib/random32.c b/lib/random32.c index b6f3325e..9085b11 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -40,16 +40,6 @@ #include <linux/sched.h> #include <asm/unaligned.h> -#ifdef CONFIG_RANDOM32_SELFTEST -static void __init prandom_state_selftest(void); -#else -static inline void prandom_state_selftest(void) -{ -} -#endif - -DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; - /** * prandom_u32_state - seeded pseudo-random number generator. * @state: pointer to state structure holding seeded state. @@ -70,25 +60,6 @@ u32 prandom_u32_state(struct rnd_state *state) EXPORT_SYMBOL(prandom_u32_state); /** - * prandom_u32 - pseudo random number generator - * - * A 32 bit pseudo-random number is generated using a fast - * algorithm suitable for simulation. This algorithm is NOT - * considered safe for cryptographic use. - */ -u32 prandom_u32(void) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - u32 res; - - res = prandom_u32_state(state); - put_cpu_var(net_rand_state); - - return res; -} -EXPORT_SYMBOL(prandom_u32); - -/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -119,20 +90,6 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) } EXPORT_SYMBOL(prandom_bytes_state); -/** - * prandom_bytes - get the requested number of pseudo-random bytes - * @buf: where to copy the pseudo-random bytes to - * @bytes: the requested number of bytes - */ -void prandom_bytes(void *buf, size_t bytes) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - - prandom_bytes_state(state, buf, bytes); - put_cpu_var(net_rand_state); -} -EXPORT_SYMBOL(prandom_bytes); - static void prandom_warmup(struct rnd_state *state) { /* Calling RNG ten times to satisfy recurrence condition */ @@ -148,96 +105,6 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static u32 __extract_hwseed(void) -{ - unsigned int val = 0; - - (void)(arch_get_random_seed_int(&val) || - arch_get_random_int(&val)); - - return val; -} - -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) -{ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ -#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) - state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); - state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); - state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); - state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); -} - -/** - * prandom_seed - add entropy to pseudo random number generator - * @seed: seed value - * - * Add some additional seeding to the prandom pool. - */ -void prandom_seed(u32 entropy) -{ - int i; - /* - * No locking on the CPUs, but then somewhat random results are, well, - * expected. - */ - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - - state->s1 = __seed(state->s1 ^ entropy, 2U); - prandom_warmup(state); - } -} -EXPORT_SYMBOL(prandom_seed); - -/* - * Generate some initially weak seeding values to allow - * to start the prandom_u32() engine. - */ -static int __init prandom_init(void) -{ - int i; - - prandom_state_selftest(); - - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - - prandom_seed_early(state, weak_seed, true); - prandom_warmup(state); - } - - return 0; -} -core_initcall(prandom_init); - -static void __prandom_timer(struct timer_list *unused); - -static DEFINE_TIMER(seed_timer, __prandom_timer); - -static void __prandom_timer(struct timer_list *unused) -{ - u32 entropy; - unsigned long expires; - - get_random_bytes(&entropy, sizeof(entropy)); - prandom_seed(entropy); - - /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ - expires = 40 + prandom_u32_max(40); - seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); - - add_timer(&seed_timer); -} - -static void __init __prandom_start_seed_timer(void) -{ - seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); - add_timer(&seed_timer); -} - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; @@ -257,51 +124,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) } EXPORT_SYMBOL(prandom_seed_full_state); -/* - * Generate better values after random number generator - * is fully initialized. - */ -static void __prandom_reseed(bool late) -{ - unsigned long flags; - static bool latch = false; - static DEFINE_SPINLOCK(lock); - - /* Asking for random bytes might result in bytes getting - * moved into the nonblocking pool and thus marking it - * as initialized. In this case we would double back into - * this function and attempt to do a late reseed. - * Ignore the pointless attempt to reseed again if we're - * already waiting for bytes when the nonblocking pool - * got initialized. - */ - - /* only allow initial seeding (late == false) once */ - if (!spin_trylock_irqsave(&lock, flags)) - return; - - if (latch && !late) - goto out; - - latch = true; - prandom_seed_full_state(&net_rand_state); -out: - spin_unlock_irqrestore(&lock, flags); -} - -void prandom_reseed_late(void) -{ - __prandom_reseed(true); -} - -static int __init prandom_reseed(void) -{ - __prandom_reseed(false); - __prandom_start_seed_timer(); - return 0; -} -late_initcall(prandom_reseed); - #ifdef CONFIG_RANDOM32_SELFTEST static struct prandom_test1 { u32 seed; @@ -421,7 +243,28 @@ static struct prandom_test2 { { 407983964U, 921U, 728767059U }, }; -static void __init prandom_state_selftest(void) +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + +static int __init prandom_state_selftest(void) { int i, j, errors = 0, runs = 0; bool error = false; @@ -461,5 +304,266 @@ static void __init prandom_state_selftest(void) pr_warn("prandom: %d/%d self tests failed\n", errors, runs); else pr_info("prandom: %d self tests passed\n", runs); + return 0; } +core_initcall(prandom_state_selftest); #endif + +/* + * The prandom_u32() implementation is now completely separate from the + * prandom_state() functions, which are retained (for now) for compatibility. + * + * Because of (ab)use in the networking code for choosing random TCP/UDP port + * numbers, which open DoS possibilities if guessable, we want something + * stronger than a standard PRNG. But the performance requirements of + * the network code do not allow robust crypto for this application. + * + * So this is a homebrew Junior Spaceman implementation, based on the + * lowest-latency trustworthy crypto primitive available, SipHash. + * (The authors of SipHash have not been consulted about this abuse of + * their work.) + * + * Standard SipHash-2-4 uses 2n+4 rounds to hash n words of input to + * one word of output. This abbreviated version uses 2 rounds per word + * of output. + */ + +struct siprand_state { + unsigned long v0; + unsigned long v1; + unsigned long v2; + unsigned long v3; +}; + +static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; + +/* + * This is the core CPRNG function. As "pseudorandom", this is not used + * for truly valuable things, just intended to be a PITA to guess. + * For maximum speed, we do just two SipHash rounds per word. This is + * the same rate as 4 rounds per 64 bits that SipHash normally uses, + * so hopefully it's reasonably secure. + * + * There are two changes from the official SipHash finalization: + * - We omit some constants XORed with v2 in the SipHash spec as irrelevant; + * they are there only to make the output rounds distinct from the input + * rounds, and this application has no input rounds. + * - Rather than returning v0^v1^v2^v3, return v1+v3. + * If you look at the SipHash round, the last operation on v3 is + * "v3 ^= v0", so "v0 ^ v3" just undoes that, a waste of time. + * Likewise "v1 ^= v2". (The rotate of v2 makes a difference, but + * it still cancels out half of the bits in v2 for no benefit.) + * Second, since the last combining operation was xor, continue the + * pattern of alternating xor/add for a tiny bit of extra non-linearity. + */ +static inline u32 siprand_u32(struct siprand_state *s) +{ + unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; + return v1 + v3; +} + + +/** + * prandom_u32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 prandom_u32(void) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u32 res = siprand_u32(state); + + put_cpu_ptr(&net_rand_state); + return res; +} +EXPORT_SYMBOL(prandom_u32); + +/** + * prandom_bytes - get the requested number of pseudo-random bytes + * @buf: where to copy the pseudo-random bytes to + * @bytes: the requested number of bytes + */ +void prandom_bytes(void *buf, size_t bytes) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(siprand_u32(state), (u32 *)ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } + + if (bytes > 0) { + u32 rem = siprand_u32(state); + + do { + *ptr++ = (u8)rem; + rem >>= BITS_PER_BYTE; + } while (--bytes > 0); + } + put_cpu_ptr(&net_rand_state); +} +EXPORT_SYMBOL(prandom_bytes); + +/** + * prandom_seed - add entropy to pseudo random number generator + * @entropy: entropy value + * + * Add some additional seed material to the prandom pool. + * The "entropy" is actually our IP address (the only caller is + * the network code), not for unpredictability, but to ensure that + * different machines are initialized differently. + */ +void prandom_seed(u32 entropy) +{ + int i; + + add_device_randomness(&entropy, sizeof(entropy)); + + for_each_possible_cpu(i) { + struct siprand_state *state = per_cpu_ptr(&net_rand_state, i); + unsigned long v0 = state->v0, v1 = state->v1; + unsigned long v2 = state->v2, v3 = state->v3; + + do { + v3 ^= entropy; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= entropy; + } while (unlikely(!v0 || !v1 || !v2 || !v3)); + + WRITE_ONCE(state->v0, v0); + WRITE_ONCE(state->v1, v1); + WRITE_ONCE(state->v2, v2); + WRITE_ONCE(state->v3, v3); + } +} +EXPORT_SYMBOL(prandom_seed); + +/* + * Generate some initially weak seeding values to allow + * the prandom_u32() engine to be started. + */ +static int __init prandom_init_early(void) +{ + int i; + unsigned long v0, v1, v2, v3; + + if (!arch_get_random_long(&v0)) + v0 = jiffies; + if (!arch_get_random_long(&v1)) + v1 = random_get_entropy(); + v2 = v0 ^ PRND_K0; + v3 = v1 ^ PRND_K1; + + for_each_possible_cpu(i) { + struct siprand_state *state; + + v3 ^= i; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= i; + + state = per_cpu_ptr(&net_rand_state, i); + state->v0 = v0; state->v1 = v1; + state->v2 = v2; state->v3 = v3; + } + + return 0; +} +core_initcall(prandom_init_early); + + +/* Stronger reseeding when available, and periodically thereafter. */ +static void prandom_reseed(struct timer_list *unused); + +static DEFINE_TIMER(seed_timer, prandom_reseed); + +static void prandom_reseed(struct timer_list *unused) +{ + unsigned long expires; + int i; + + /* + * Reinitialize each CPU's PRNG with 128 bits of key. + * No locking on the CPUs, but then somewhat random results are, + * well, expected. + */ + for_each_possible_cpu(i) { + struct siprand_state *state; + unsigned long v0 = get_random_long(), v2 = v0 ^ PRND_K0; + unsigned long v1 = get_random_long(), v3 = v1 ^ PRND_K1; +#if BITS_PER_LONG == 32 + int j; + + /* + * On 32-bit machines, hash in two extra words to + * approximate 128-bit key length. Not that the hash + * has that much security, but this prevents a trivial + * 64-bit brute force. + */ + for (j = 0; j < 2; j++) { + unsigned long m = get_random_long(); + + v3 ^= m; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= m; + } +#endif + /* + * Probably impossible in practice, but there is a + * theoretical risk that a race between this reseeding + * and the target CPU writing its state back could + * create the all-zero SipHash fixed point. + * + * To ensure that never happens, ensure the state + * we write contains no zero words. + */ + state = per_cpu_ptr(&net_rand_state, i); + WRITE_ONCE(state->v0, v0 ? v0 : -1ul); + WRITE_ONCE(state->v1, v1 ? v1 : -1ul); + WRITE_ONCE(state->v2, v2 ? v2 : -1ul); + WRITE_ONCE(state->v3, v3 ? v3 : -1ul); + } + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = round_jiffies(jiffies + 40 * HZ + prandom_u32_max(40 * HZ)); + mod_timer(&seed_timer, expires); +} + +/* + * The random ready callback can be called from almost any interrupt. + * To avoid worrying about whether it's safe to delay that interrupt + * long enough to seed all CPUs, just schedule an immediate timer event. + */ +static void prandom_timer_start(struct random_ready_callback *unused) +{ + mod_timer(&seed_timer, jiffies); +} + +/* + * Start periodic full reseeding as soon as strong + * random numbers are available. + */ +static int __init prandom_init_late(void) +{ + static struct random_ready_callback random_ready = { + .func = prandom_timer_start + }; + int ret = add_random_ready_callback(&random_ready); + + if (ret == -EALREADY) { + prandom_timer_start(&random_ready); + ret = 0; + } + return ret; +} +late_initcall(prandom_init_late); -- 2.9.0

4 years, 7 months

[PATCH 5.4] random32: make prandom_u32() output unpredictable

by Willy Tarreau

From: George Spelvin <lkml(a)sdf.org> commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity(a)gmail.com> Cc: Willy Tarreau <w(a)1wt.eu> Cc: Eric Dumazet <edumazet(a)google.com> Cc: "Jason A. Donenfeld" <Jason(a)zx2c4.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: tytso(a)mit.edu Cc: Florian Westphal <fw(a)strlen.de> Cc: Marc Plumb <lkml.mplumb(a)gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml(a)sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau <w(a)1wt.eu> [wt: backported to 5.4 -- no tracepoint there] Signed-off-by: Willy Tarreau <w(a)1wt.eu> --- drivers/char/random.c | 1 - include/linux/prandom.h | 36 +++- kernel/time/timer.c | 7 - lib/random32.c | 462 +++++++++++++++++++++++++++++------------------- 4 files changed, 317 insertions(+), 189 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 75a8f7f..2c29f83 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1330,7 +1330,6 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); - this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && diff --git a/include/linux/prandom.h b/include/linux/prandom.h index aa16e64..cc1e713 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,12 +16,44 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +#if BITS_PER_LONG == 64 +/* + * The core SipHash round function. Each line can be executed in + * parallel given enough CPU resources. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol64(v1, 13), v2 += v3, v3 = rol64(v3, 16), \ + v1 ^= v0, v0 = rol64(v0, 32), v3 ^= v2, \ + v0 += v3, v3 = rol64(v3, 21), v2 += v1, v1 = rol64(v1, 17), \ + v3 ^= v0, v1 ^= v2, v2 = rol64(v2, 32) \ +) + +#define PRND_K0 (0x736f6d6570736575 ^ 0x6c7967656e657261) +#define PRND_K1 (0x646f72616e646f6d ^ 0x7465646279746573) + +#elif BITS_PER_LONG == 32 +/* + * On 32-bit machines, we use HSipHash, a reduced-width version of SipHash. + * This is weaker, but 32-bit machines are not used for high-traffic + * applications, so there is less output for an attacker to analyze. + */ +#define PRND_SIPROUND(v0, v1, v2, v3) ( \ + v0 += v1, v1 = rol32(v1, 5), v2 += v3, v3 = rol32(v3, 8), \ + v1 ^= v0, v0 = rol32(v0, 16), v3 ^= v2, \ + v0 += v3, v3 = rol32(v3, 7), v2 += v1, v1 = rol32(v1, 13), \ + v3 ^= v0, v1 ^= v2, v2 = rol32(v2, 16) \ +) +#define PRND_K0 0x6c796765 +#define PRND_K1 0x74656462 + +#else +#error Unsupported BITS_PER_LONG +#endif + struct rnd_state { __u32 s1, s2, s3, s4; }; -DECLARE_PER_CPU(struct rnd_state, net_rand_state); - u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index a3ae244..87fa73c 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1743,13 +1743,6 @@ void update_process_times(int user_tick) scheduler_tick(); if (IS_ENABLED(CONFIG_POSIX_TIMERS)) run_posix_cpu_timers(); - - /* The current CPU might make use of net randoms without receiving IRQs - * to renew them often enough. Let's update the net_rand_state from a - * non-constant value that's not affine to the number of calls to make - * sure it's updated when there's some activity (we don't care in idle). - */ - this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /** diff --git a/lib/random32.c b/lib/random32.c index 1786f78..9085b11 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -40,16 +40,6 @@ #include <linux/sched.h> #include <asm/unaligned.h> -#ifdef CONFIG_RANDOM32_SELFTEST -static void __init prandom_state_selftest(void); -#else -static inline void prandom_state_selftest(void) -{ -} -#endif - -DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; - /** * prandom_u32_state - seeded pseudo-random number generator. * @state: pointer to state structure holding seeded state. @@ -70,25 +60,6 @@ u32 prandom_u32_state(struct rnd_state *state) EXPORT_SYMBOL(prandom_u32_state); /** - * prandom_u32 - pseudo random number generator - * - * A 32 bit pseudo-random number is generated using a fast - * algorithm suitable for simulation. This algorithm is NOT - * considered safe for cryptographic use. - */ -u32 prandom_u32(void) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - u32 res; - - res = prandom_u32_state(state); - put_cpu_var(net_rand_state); - - return res; -} -EXPORT_SYMBOL(prandom_u32); - -/** * prandom_bytes_state - get the requested number of pseudo-random bytes * * @state: pointer to state structure holding seeded state. @@ -119,20 +90,6 @@ void prandom_bytes_state(struct rnd_state *state, void *buf, size_t bytes) } EXPORT_SYMBOL(prandom_bytes_state); -/** - * prandom_bytes - get the requested number of pseudo-random bytes - * @buf: where to copy the pseudo-random bytes to - * @bytes: the requested number of bytes - */ -void prandom_bytes(void *buf, size_t bytes) -{ - struct rnd_state *state = &get_cpu_var(net_rand_state); - - prandom_bytes_state(state, buf, bytes); - put_cpu_var(net_rand_state); -} -EXPORT_SYMBOL(prandom_bytes); - static void prandom_warmup(struct rnd_state *state) { /* Calling RNG ten times to satisfy recurrence condition */ @@ -148,96 +105,6 @@ static void prandom_warmup(struct rnd_state *state) prandom_u32_state(state); } -static u32 __extract_hwseed(void) -{ - unsigned int val = 0; - - (void)(arch_get_random_seed_int(&val) || - arch_get_random_int(&val)); - - return val; -} - -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) -{ -#define LCG(x) ((x) * 69069U) /* super-duper LCG */ -#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) - state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); - state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); - state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); - state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); -} - -/** - * prandom_seed - add entropy to pseudo random number generator - * @entropy: entropy value - * - * Add some additional entropy to the prandom pool. - */ -void prandom_seed(u32 entropy) -{ - int i; - /* - * No locking on the CPUs, but then somewhat random results are, well, - * expected. - */ - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - - state->s1 = __seed(state->s1 ^ entropy, 2U); - prandom_warmup(state); - } -} -EXPORT_SYMBOL(prandom_seed); - -/* - * Generate some initially weak seeding values to allow - * to start the prandom_u32() engine. - */ -static int __init prandom_init(void) -{ - int i; - - prandom_state_selftest(); - - for_each_possible_cpu(i) { - struct rnd_state *state = &per_cpu(net_rand_state, i); - u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - - prandom_seed_early(state, weak_seed, true); - prandom_warmup(state); - } - - return 0; -} -core_initcall(prandom_init); - -static void __prandom_timer(struct timer_list *unused); - -static DEFINE_TIMER(seed_timer, __prandom_timer); - -static void __prandom_timer(struct timer_list *unused) -{ - u32 entropy; - unsigned long expires; - - get_random_bytes(&entropy, sizeof(entropy)); - prandom_seed(entropy); - - /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ - expires = 40 + prandom_u32_max(40); - seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC); - - add_timer(&seed_timer); -} - -static void __init __prandom_start_seed_timer(void) -{ - seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC); - add_timer(&seed_timer); -} - void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) { int i; @@ -257,51 +124,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state) } EXPORT_SYMBOL(prandom_seed_full_state); -/* - * Generate better values after random number generator - * is fully initialized. - */ -static void __prandom_reseed(bool late) -{ - unsigned long flags; - static bool latch = false; - static DEFINE_SPINLOCK(lock); - - /* Asking for random bytes might result in bytes getting - * moved into the nonblocking pool and thus marking it - * as initialized. In this case we would double back into - * this function and attempt to do a late reseed. - * Ignore the pointless attempt to reseed again if we're - * already waiting for bytes when the nonblocking pool - * got initialized. - */ - - /* only allow initial seeding (late == false) once */ - if (!spin_trylock_irqsave(&lock, flags)) - return; - - if (latch && !late) - goto out; - - latch = true; - prandom_seed_full_state(&net_rand_state); -out: - spin_unlock_irqrestore(&lock, flags); -} - -void prandom_reseed_late(void) -{ - __prandom_reseed(true); -} - -static int __init prandom_reseed(void) -{ - __prandom_reseed(false); - __prandom_start_seed_timer(); - return 0; -} -late_initcall(prandom_reseed); - #ifdef CONFIG_RANDOM32_SELFTEST static struct prandom_test1 { u32 seed; @@ -421,7 +243,28 @@ static struct prandom_test2 { { 407983964U, 921U, 728767059U }, }; -static void __init prandom_state_selftest(void) +static u32 __extract_hwseed(void) +{ + unsigned int val = 0; + + (void)(arch_get_random_seed_int(&val) || + arch_get_random_int(&val)); + + return val; +} + +static void prandom_seed_early(struct rnd_state *state, u32 seed, + bool mix_with_hwseed) +{ +#define LCG(x) ((x) * 69069U) /* super-duper LCG */ +#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) + state->s1 = __seed(HWSEED() ^ LCG(seed), 2U); + state->s2 = __seed(HWSEED() ^ LCG(state->s1), 8U); + state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); + state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); +} + +static int __init prandom_state_selftest(void) { int i, j, errors = 0, runs = 0; bool error = false; @@ -461,5 +304,266 @@ static void __init prandom_state_selftest(void) pr_warn("prandom: %d/%d self tests failed\n", errors, runs); else pr_info("prandom: %d self tests passed\n", runs); + return 0; +} +core_initcall(prandom_state_selftest); +#endif + +/* + * The prandom_u32() implementation is now completely separate from the + * prandom_state() functions, which are retained (for now) for compatibility. + * + * Because of (ab)use in the networking code for choosing random TCP/UDP port + * numbers, which open DoS possibilities if guessable, we want something + * stronger than a standard PRNG. But the performance requirements of + * the network code do not allow robust crypto for this application. + * + * So this is a homebrew Junior Spaceman implementation, based on the + * lowest-latency trustworthy crypto primitive available, SipHash. + * (The authors of SipHash have not been consulted about this abuse of + * their work.) + * + * Standard SipHash-2-4 uses 2n+4 rounds to hash n words of input to + * one word of output. This abbreviated version uses 2 rounds per word + * of output. + */ + +struct siprand_state { + unsigned long v0; + unsigned long v1; + unsigned long v2; + unsigned long v3; +}; + +static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; + +/* + * This is the core CPRNG function. As "pseudorandom", this is not used + * for truly valuable things, just intended to be a PITA to guess. + * For maximum speed, we do just two SipHash rounds per word. This is + * the same rate as 4 rounds per 64 bits that SipHash normally uses, + * so hopefully it's reasonably secure. + * + * There are two changes from the official SipHash finalization: + * - We omit some constants XORed with v2 in the SipHash spec as irrelevant; + * they are there only to make the output rounds distinct from the input + * rounds, and this application has no input rounds. + * - Rather than returning v0^v1^v2^v3, return v1+v3. + * If you look at the SipHash round, the last operation on v3 is + * "v3 ^= v0", so "v0 ^ v3" just undoes that, a waste of time. + * Likewise "v1 ^= v2". (The rotate of v2 makes a difference, but + * it still cancels out half of the bits in v2 for no benefit.) + * Second, since the last combining operation was xor, continue the + * pattern of alternating xor/add for a tiny bit of extra non-linearity. + */ +static inline u32 siprand_u32(struct siprand_state *s) +{ + unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; + return v1 + v3; +} + + +/** + * prandom_u32 - pseudo random number generator + * + * A 32 bit pseudo-random number is generated using a fast + * algorithm suitable for simulation. This algorithm is NOT + * considered safe for cryptographic use. + */ +u32 prandom_u32(void) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u32 res = siprand_u32(state); + + put_cpu_ptr(&net_rand_state); + return res; +} +EXPORT_SYMBOL(prandom_u32); + +/** + * prandom_bytes - get the requested number of pseudo-random bytes + * @buf: where to copy the pseudo-random bytes to + * @bytes: the requested number of bytes + */ +void prandom_bytes(void *buf, size_t bytes) +{ + struct siprand_state *state = get_cpu_ptr(&net_rand_state); + u8 *ptr = buf; + + while (bytes >= sizeof(u32)) { + put_unaligned(siprand_u32(state), (u32 *)ptr); + ptr += sizeof(u32); + bytes -= sizeof(u32); + } + + if (bytes > 0) { + u32 rem = siprand_u32(state); + + do { + *ptr++ = (u8)rem; + rem >>= BITS_PER_BYTE; + } while (--bytes > 0); + } + put_cpu_ptr(&net_rand_state); +} +EXPORT_SYMBOL(prandom_bytes); + +/** + * prandom_seed - add entropy to pseudo random number generator + * @entropy: entropy value + * + * Add some additional seed material to the prandom pool. + * The "entropy" is actually our IP address (the only caller is + * the network code), not for unpredictability, but to ensure that + * different machines are initialized differently. + */ +void prandom_seed(u32 entropy) +{ + int i; + + add_device_randomness(&entropy, sizeof(entropy)); + + for_each_possible_cpu(i) { + struct siprand_state *state = per_cpu_ptr(&net_rand_state, i); + unsigned long v0 = state->v0, v1 = state->v1; + unsigned long v2 = state->v2, v3 = state->v3; + + do { + v3 ^= entropy; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= entropy; + } while (unlikely(!v0 || !v1 || !v2 || !v3)); + + WRITE_ONCE(state->v0, v0); + WRITE_ONCE(state->v1, v1); + WRITE_ONCE(state->v2, v2); + WRITE_ONCE(state->v3, v3); + } +} +EXPORT_SYMBOL(prandom_seed); + +/* + * Generate some initially weak seeding values to allow + * the prandom_u32() engine to be started. + */ +static int __init prandom_init_early(void) +{ + int i; + unsigned long v0, v1, v2, v3; + + if (!arch_get_random_long(&v0)) + v0 = jiffies; + if (!arch_get_random_long(&v1)) + v1 = random_get_entropy(); + v2 = v0 ^ PRND_K0; + v3 = v1 ^ PRND_K1; + + for_each_possible_cpu(i) { + struct siprand_state *state; + + v3 ^= i; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= i; + + state = per_cpu_ptr(&net_rand_state, i); + state->v0 = v0; state->v1 = v1; + state->v2 = v2; state->v3 = v3; + } + + return 0; } +core_initcall(prandom_init_early); + + +/* Stronger reseeding when available, and periodically thereafter. */ +static void prandom_reseed(struct timer_list *unused); + +static DEFINE_TIMER(seed_timer, prandom_reseed); + +static void prandom_reseed(struct timer_list *unused) +{ + unsigned long expires; + int i; + + /* + * Reinitialize each CPU's PRNG with 128 bits of key. + * No locking on the CPUs, but then somewhat random results are, + * well, expected. + */ + for_each_possible_cpu(i) { + struct siprand_state *state; + unsigned long v0 = get_random_long(), v2 = v0 ^ PRND_K0; + unsigned long v1 = get_random_long(), v3 = v1 ^ PRND_K1; +#if BITS_PER_LONG == 32 + int j; + + /* + * On 32-bit machines, hash in two extra words to + * approximate 128-bit key length. Not that the hash + * has that much security, but this prevents a trivial + * 64-bit brute force. + */ + for (j = 0; j < 2; j++) { + unsigned long m = get_random_long(); + + v3 ^= m; + PRND_SIPROUND(v0, v1, v2, v3); + PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= m; + } #endif + /* + * Probably impossible in practice, but there is a + * theoretical risk that a race between this reseeding + * and the target CPU writing its state back could + * create the all-zero SipHash fixed point. + * + * To ensure that never happens, ensure the state + * we write contains no zero words. + */ + state = per_cpu_ptr(&net_rand_state, i); + WRITE_ONCE(state->v0, v0 ? v0 : -1ul); + WRITE_ONCE(state->v1, v1 ? v1 : -1ul); + WRITE_ONCE(state->v2, v2 ? v2 : -1ul); + WRITE_ONCE(state->v3, v3 ? v3 : -1ul); + } + + /* reseed every ~60 seconds, in [40 .. 80) interval with slack */ + expires = round_jiffies(jiffies + 40 * HZ + prandom_u32_max(40 * HZ)); + mod_timer(&seed_timer, expires); +} + +/* + * The random ready callback can be called from almost any interrupt. + * To avoid worrying about whether it's safe to delay that interrupt + * long enough to seed all CPUs, just schedule an immediate timer event. + */ +static void prandom_timer_start(struct random_ready_callback *unused) +{ + mod_timer(&seed_timer, jiffies); +} + +/* + * Start periodic full reseeding as soon as strong + * random numbers are available. + */ +static int __init prandom_init_late(void) +{ + static struct random_ready_callback random_ready = { + .func = prandom_timer_start + }; + int ret = add_random_ready_callback(&random_ready); + + if (ret == -EALREADY) { + prandom_timer_start(&random_ready); + ret = 0; + } + return ret; +} +late_initcall(prandom_init_late); -- 2.9.0

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Linux-stable-mirror November 2020