diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 726ac2e01b77..08e153614e09 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -480,16 +480,17 @@ Description: information about CPUs heterogeneity. cpu_capacity: capacity of cpu#.

What: /sys/devices/system/cpu/vulnerabilities + /sys/devices/system/cpu/vulnerabilities/gather_data_sampling + /sys/devices/system/cpu/vulnerabilities/itlb_multihit + /sys/devices/system/cpu/vulnerabilities/l1tf + /sys/devices/system/cpu/vulnerabilities/mds /sys/devices/system/cpu/vulnerabilities/meltdown + /sys/devices/system/cpu/vulnerabilities/mmio_stale_data + /sys/devices/system/cpu/vulnerabilities/spec_store_bypass /sys/devices/system/cpu/vulnerabilities/spectre_v1 /sys/devices/system/cpu/vulnerabilities/spectre_v2 - /sys/devices/system/cpu/vulnerabilities/spec_store_bypass - /sys/devices/system/cpu/vulnerabilities/l1tf - /sys/devices/system/cpu/vulnerabilities/mds /sys/devices/system/cpu/vulnerabilities/srbds /sys/devices/system/cpu/vulnerabilities/tsx_async_abort - /sys/devices/system/cpu/vulnerabilities/itlb_multihit - /sys/devices/system/cpu/vulnerabilities/mmio_stale_data Date: January 2018 Contact: Linux kernel mailing list linux-kernel@vger.kernel.org Description: Information about CPU vulnerabilities diff --git a/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst b/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst new file mode 100644 index 000000000000..264bfa937f7d --- /dev/null +++ b/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +GDS - Gather Data Sampling +========================== + +Gather Data Sampling is a hardware vulnerability which allows unprivileged +speculative access to data which was previously stored in vector registers. + +Problem +------- +When a gather instruction performs loads from memory, different data elements +are merged into the destination vector register. However, when a gather +instruction that is transiently executed encounters a fault, stale data from +architectural or internal vector registers may get transiently forwarded to the +destination vector register instead. This will allow a malicious attacker to +infer stale data using typical side channel techniques like cache timing +attacks. GDS is a purely sampling-based attack. + +The attacker uses gather instructions to infer the stale vector register data. +The victim does not need to do anything special other than use the vector +registers. The victim does not need to use gather instructions to be +vulnerable. + +Because the buffers are shared between Hyper-Threads cross Hyper-Thread attacks +are possible. + +Attack scenarios +---------------- +Without mitigation, GDS can infer stale data across virtually all +permission boundaries: + + Non-enclaves can infer SGX enclave data + Userspace can infer kernel data + Guests can infer data from hosts + Guest can infer guest from other guests + Users can infer data from other users + +Because of this, it is important to ensure that the mitigation stays enabled in +lower-privilege contexts like guests and when running outside SGX enclaves. + +The hardware enforces the mitigation for SGX. Likewise, VMMs should ensure +that guests are not allowed to disable the GDS mitigation. If a host erred and +allowed this, a guest could theoretically disable GDS mitigation, mount an +attack, and re-enable it. + +Mitigation mechanism +-------------------- +This issue is mitigated in microcode. The microcode defines the following new +bits: + + ================================ === ============================ + IA32_ARCH_CAPABILITIES[GDS_CTRL] R/O Enumerates GDS vulnerability + and mitigation support. + IA32_ARCH_CAPABILITIES[GDS_NO] R/O Processor is not vulnerable. + IA32_MCU_OPT_CTRL[GDS_MITG_DIS] R/W Disables the mitigation + 0 by default. + IA32_MCU_OPT_CTRL[GDS_MITG_LOCK] R/W Locks GDS_MITG_DIS=0. Writes + to GDS_MITG_DIS are ignored + Can't be cleared once set. + ================================ === ============================ + +GDS can also be mitigated on systems that don't have updated microcode by +disabling AVX. This can be done by setting gather_data_sampling="force" or +"clearcpuid=avx" on the kernel command-line. + +If used, these options will disable AVX use by turning off XSAVE YMM support. +However, the processor will still enumerate AVX support. Userspace that +does not follow proper AVX enumeration to check both AVX *and* XSAVE YMM +support will break. + +Mitigation control on the kernel command line +--------------------------------------------- +The mitigation can be disabled by setting "gather_data_sampling=off" or +"mitigations=off" on the kernel command line. Not specifying either will default +to the mitigation being enabled. Specifying "gather_data_sampling=force" will +use the microcode mitigation when available or disable AVX on affected systems +where the microcode hasn't been updated to include the mitigation. + +GDS System Information +------------------------ +The kernel provides vulnerability status information through sysfs. For +GDS this can be accessed by the following sysfs file: + +/sys/devices/system/cpu/vulnerabilities/gather_data_sampling + +The possible values contained in this file are: + + ============================== ============================================= + Not affected Processor not vulnerable. + Vulnerable Processor vulnerable and mitigation disabled. + Vulnerable: No microcode Processor vulnerable and microcode is missing + mitigation. + Mitigation: AVX disabled, + no microcode Processor is vulnerable and microcode is missing + mitigation. AVX disabled as mitigation. + Mitigation: Microcode Processor is vulnerable and mitigation is in + effect. + Mitigation: Microcode (locked) Processor is vulnerable and mitigation is in + effect and cannot be disabled. + Unknown: Dependent on + hypervisor status Running on a virtual guest processor that is + affected but with no way to know if host + processor is mitigated or vulnerable. + ============================== ============================================= + +GDS Default mitigation +---------------------- +The updated microcode will enable the mitigation by default. The kernel's +default action is to leave the mitigation enabled. diff --git a/Documentation/admin-guide/hw-vuln/index.rst b/Documentation/admin-guide/hw-vuln/index.rst index 2adec1e6520a..245468b0f2be 100644 --- a/Documentation/admin-guide/hw-vuln/index.rst +++ b/Documentation/admin-guide/hw-vuln/index.rst @@ -16,3 +16,4 @@ are configurable at compile, boot or run time. multihit.rst special-register-buffer-data-sampling.rst processor_mmio_stale_data.rst + gather_data_sampling.rst diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9d2185616d1a..51f845419b9c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1336,6 +1336,26 @@ Format: off | on default: on

+ gather_data_sampling= + [X86,INTEL] Control the Gather Data Sampling (GDS) + mitigation. + + Gather Data Sampling is a hardware vulnerability which + allows unprivileged speculative access to data which was + previously stored in vector registers. + + This issue is mitigated by default in updated microcode. + The mitigation may have a performance impact but can be + disabled. On systems without the microcode mitigation + disabling AVX serves as a mitigation. + + force: Disable AVX to mitigate systems without + microcode mitigation. No effect if the microcode + mitigation is present. Known to cause crashes in + userspace with buggy AVX enumeration. + + off: Disable GDS mitigation. + gcov_persist= [GCOV] When non-zero (default), profiling data for kernel modules is saved and remains accessible via debugfs, even when the module is unloaded/reloaded. @@ -2696,21 +2716,22 @@ Disable all optional CPU mitigations. This improves system performance, but it may also expose users to several CPU vulnerabilities. - Equivalent to: nopti [X86,PPC] + Equivalent to: gather_data_sampling=off [X86] kpti=0 [ARM64] - nospectre_v1 [X86,PPC] + kvm.nx_huge_pages=off [X86] + l1tf=off [X86] + mds=off [X86] + mmio_stale_data=off [X86] + no_entry_flush [PPC] + no_uaccess_flush [PPC] nobp=0 [S390] + nopti [X86,PPC] + nospectre_v1 [X86,PPC] nospectre_v2 [X86,PPC,S390,ARM64] - spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86,PPC] + spectre_v2_user=off [X86] ssbd=force-off [ARM64] - l1tf=off [X86] - mds=off [X86] tsx_async_abort=off [X86] - kvm.nx_huge_pages=off [X86] - no_entry_flush [PPC] - no_uaccess_flush [PPC] - mmio_stale_data=off [X86]

Exceptions: This does not have any effect on diff --git a/Makefile b/Makefile index 0b17d6936c2f..be75dc3ae8de 100644 --- a/Makefile +++ b/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 VERSION = 5 PATCHLEVEL = 4 -SUBLEVEL = 251 +SUBLEVEL = 252 EXTRAVERSION = NAME = Kleptomaniac Octopus

diff --git a/arch/Kconfig b/arch/Kconfig index 2219a07dca1e..4d03616bf597 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -271,6 +271,9 @@ config ARCH_HAS_UNCACHED_SEGMENT select ARCH_HAS_DMA_PREP_COHERENT bool

+config ARCH_HAS_CPU_FINALIZE_INIT + bool + # Select if arch init_task must go in the __init_task_data section config ARCH_TASK_STRUCT_ON_STACK bool diff --git a/arch/alpha/include/asm/bugs.h b/arch/alpha/include/asm/bugs.h deleted file mode 100644 index 78030d1c7e7e..000000000000 --- a/arch/alpha/include/asm/bugs.h +++ /dev/null @@ -1,20 +0,0 @@ -/* - * include/asm-alpha/bugs.h - * - * Copyright (C) 1994 Linus Torvalds - */ - -/* - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Needs: - * void check_bugs(void); - */ - -/* - * I don't know of any alpha bugs yet.. Nice chip - */ - -static void check_bugs(void) -{ -} diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index a70696a95b79..2feb5dade121 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -5,6 +5,7 @@ config ARM select ARCH_32BIT_OFF_T select ARCH_CLOCKSOURCE_DATA select ARCH_HAS_BINFMT_FLAT + select ARCH_HAS_CPU_FINALIZE_INIT if MMU select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h index 97a312ba0840..fe385551edec 100644 --- a/arch/arm/include/asm/bugs.h +++ b/arch/arm/include/asm/bugs.h @@ -1,7 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /* - * arch/arm/include/asm/bugs.h - * * Copyright (C) 1995-2003 Russell King */ #ifndef __ASM_BUGS_H @@ -10,10 +8,8 @@ extern void check_writebuffer_bugs(void);

#ifdef CONFIG_MMU -extern void check_bugs(void); extern void check_other_bugs(void); #else -#define check_bugs() do { } while (0) #define check_other_bugs() do { } while (0) #endif

diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c index 14c8dbbb7d2d..087bce6ec8e9 100644 --- a/arch/arm/kernel/bugs.c +++ b/arch/arm/kernel/bugs.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/init.h> +#include <linux/cpu.h> #include <asm/bugs.h> #include <asm/proc-fns.h>

@@ -11,7 +12,7 @@ void check_other_bugs(void) #endif }

-void __init check_bugs(void) +void __init arch_cpu_finalize_init(void) { check_writebuffer_bugs(); check_other_bugs(); diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 6a6036f16abe..72dc0ac46d6b 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -8,6 +8,7 @@ menu "Processor type and features"

config IA64 bool + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO select ACPI diff --git a/arch/ia64/include/asm/bugs.h b/arch/ia64/include/asm/bugs.h deleted file mode 100644 index 0d6b9bded56c..000000000000 --- a/arch/ia64/include/asm/bugs.h +++ /dev/null @@ -1,20 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Needs: - * void check_bugs(void); - * - * Based on <asm-alpha/bugs.h>. - * - * Modified 1998, 1999, 2003 - * David Mosberger-Tang davidm@hpl.hp.com, Hewlett-Packard Co. - */ -#ifndef _ASM_IA64_BUGS_H -#define _ASM_IA64_BUGS_H - -#include <asm/processor.h> - -extern void check_bugs (void); - -#endif /* _ASM_IA64_BUGS_H */ diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index bb320c6d0cc9..6700f066f59c 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -1073,8 +1073,7 @@ cpu_init (void) } }

-void __init -check_bugs (void) +void __init arch_cpu_finalize_init(void) { ia64_patch_mckinley_e9((unsigned long) __start___mckinley_e9_bundles, (unsigned long) __end___mckinley_e9_bundles); diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 6663f1741798..d84a6a63d36a 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -4,6 +4,7 @@ config M68K default y select ARCH_32BIT_OFF_T select ARCH_HAS_BINFMT_FLAT + select ARCH_HAS_CPU_FINALIZE_INIT if MMU select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA select ARCH_MIGHT_HAVE_PC_PARPORT if ISA diff --git a/arch/m68k/include/asm/bugs.h b/arch/m68k/include/asm/bugs.h deleted file mode 100644 index 745530651e0b..000000000000 --- a/arch/m68k/include/asm/bugs.h +++ /dev/null @@ -1,21 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * include/asm-m68k/bugs.h - * - * Copyright (C) 1994 Linus Torvalds - */ - -/* - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Needs: - * void check_bugs(void); - */ - -#ifdef CONFIG_MMU -extern void check_bugs(void); /* in arch/m68k/kernel/setup.c */ -#else -static void check_bugs(void) -{ -} -#endif diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c index 528484feff80..a9ef8b6b01bc 100644 --- a/arch/m68k/kernel/setup_mm.c +++ b/arch/m68k/kernel/setup_mm.c @@ -10,6 +10,7 @@ */

#include <linux/kernel.h> +#include <linux/cpu.h> #include <linux/mm.h> #include <linux/sched.h> #include <linux/delay.h> @@ -527,7 +528,7 @@ static int __init proc_hardware_init(void) module_init(proc_hardware_init); #endif

-void check_bugs(void) +void __init arch_cpu_finalize_init(void) { #if defined(CONFIG_FPU) && !defined(CONFIG_M68KFPU_EMU) if (m68k_fputype == 0) { diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 2811ecc1f3c7..a353d1d1b457 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -5,6 +5,7 @@ config MIPS select ARCH_32BIT_OFF_T if !64BIT select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT select ARCH_CLOCKSOURCE_DATA + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_SUPPORTS_UPROBES diff --git a/arch/mips/include/asm/bugs.h b/arch/mips/include/asm/bugs.h index d8ab8b7129b5..6d04d7d3a8f2 100644 --- a/arch/mips/include/asm/bugs.h +++ b/arch/mips/include/asm/bugs.h @@ -1,17 +1,11 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* - * This is included by init/main.c to check for architecture-dependent bugs. - * * Copyright (C) 2007 Maciej W. Rozycki - * - * Needs: - * void check_bugs(void); */ #ifndef _ASM_BUGS_H #define _ASM_BUGS_H

#include <linux/bug.h> -#include <linux/delay.h> #include <linux/smp.h>

#include <asm/cpu.h> @@ -31,17 +25,6 @@ static inline void check_bugs_early(void) #endif }

-static inline void check_bugs(void) -{ - unsigned int cpu = smp_processor_id(); - - cpu_data[cpu].udelay_val = loops_per_jiffy; - check_bugs32(); -#ifdef CONFIG_64BIT - check_bugs64(); -#endif -} - static inline int r4k_daddiu_bug(void) { #ifdef CONFIG_64BIT diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index d91b772214b5..1c4114f8f9aa 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -11,6 +11,8 @@ * Copyright (C) 2000, 2001, 2002, 2007 Maciej W. Rozycki */ #include <linux/init.h> +#include <linux/cpu.h> +#include <linux/delay.h> #include <linux/ioport.h> #include <linux/export.h> #include <linux/screen_info.h> @@ -812,3 +814,14 @@ static int __init setnocoherentio(char *str) } early_param("nocoherentio", setnocoherentio); #endif + +void __init arch_cpu_finalize_init(void) +{ + unsigned int cpu = smp_processor_id(); + + cpu_data[cpu].udelay_val = loops_per_jiffy; + check_bugs32(); + + if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64)) + check_bugs64(); +} diff --git a/arch/parisc/include/asm/bugs.h b/arch/parisc/include/asm/bugs.h deleted file mode 100644 index 0a7f9db6bd1c..000000000000 --- a/arch/parisc/include/asm/bugs.h +++ /dev/null @@ -1,20 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * include/asm-parisc/bugs.h - * - * Copyright (C) 1999 Mike Shaver - */ - -/* - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Needs: - * void check_bugs(void); - */ - -#include <asm/processor.h> - -static inline void check_bugs(void) -{ -// identify_cpu(&boot_cpu_data); -} diff --git a/arch/powerpc/include/asm/bugs.h b/arch/powerpc/include/asm/bugs.h deleted file mode 100644 index 01b8f6ca4dbb..000000000000 --- a/arch/powerpc/include/asm/bugs.h +++ /dev/null @@ -1,15 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -#ifndef _ASM_POWERPC_BUGS_H -#define _ASM_POWERPC_BUGS_H - -/* - */ - -/* - * This file is included by 'init/main.c' to check for - * architecture-dependent bugs. - */ - -static inline void check_bugs(void) { } - -#endif /* _ASM_POWERPC_BUGS_H */ diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index f356ee674d89..671897a680ca 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -2,6 +2,7 @@ config SUPERH def_bool y select ARCH_HAS_BINFMT_FLAT if !MMU + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_MIGHT_HAVE_PC_PARPORT diff --git a/arch/sh/include/asm/bugs.h b/arch/sh/include/asm/bugs.h deleted file mode 100644 index 030df56bfdb2..000000000000 --- a/arch/sh/include/asm/bugs.h +++ /dev/null @@ -1,78 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __ASM_SH_BUGS_H -#define __ASM_SH_BUGS_H - -/* - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Needs: - * void check_bugs(void); - */ - -/* - * I don't know of any Super-H bugs yet. - */ - -#include <asm/processor.h> - -extern void select_idle_routine(void); - -static void __init check_bugs(void) -{ - extern unsigned long loops_per_jiffy; - char *p = &init_utsname()->machine[2]; /* "sh" */ - - select_idle_routine(); - - current_cpu_data.loops_per_jiffy = loops_per_jiffy; - - switch (current_cpu_data.family) { - case CPU_FAMILY_SH2: - *p++ = '2'; - break; - case CPU_FAMILY_SH2A: - *p++ = '2'; - *p++ = 'a'; - break; - case CPU_FAMILY_SH3: - *p++ = '3'; - break; - case CPU_FAMILY_SH4: - *p++ = '4'; - break; - case CPU_FAMILY_SH4A: - *p++ = '4'; - *p++ = 'a'; - break; - case CPU_FAMILY_SH4AL_DSP: - *p++ = '4'; - *p++ = 'a'; - *p++ = 'l'; - *p++ = '-'; - *p++ = 'd'; - *p++ = 's'; - *p++ = 'p'; - break; - case CPU_FAMILY_SH5: - *p++ = '6'; - *p++ = '4'; - break; - case CPU_FAMILY_UNKNOWN: - /* - * Specifically use CPU_FAMILY_UNKNOWN rather than - * default:, so we're able to have the compiler whine - * about unhandled enumerations. - */ - break; - } - - printk("CPU: %s\n", get_cpu_subtype(&current_cpu_data)); - -#ifndef __LITTLE_ENDIAN__ - /* 'eb' means 'Endian Big' */ - *p++ = 'e'; - *p++ = 'b'; -#endif - *p = '\0'; -} -#endif /* __ASM_SH_BUGS_H */ diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h index 6fbf8c80e498..386786b1594a 100644 --- a/arch/sh/include/asm/processor.h +++ b/arch/sh/include/asm/processor.h @@ -173,6 +173,8 @@ extern unsigned int instruction_size(unsigned int insn); #define instruction_size(insn) (4) #endif

+void select_idle_routine(void); + #endif /* __ASSEMBLY__ */

#ifdef CONFIG_SUPERH32 diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c index c20fc5487e05..bcb8eabd7618 100644 --- a/arch/sh/kernel/idle.c +++ b/arch/sh/kernel/idle.c @@ -15,6 +15,7 @@ #include <linux/smp.h> #include <linux/atomic.h> #include <asm/pgalloc.h> +#include <asm/processor.h> #include <asm/smp.h> #include <asm/bl_bit.h>

diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c index c25ee383cb83..2221e057e6b4 100644 --- a/arch/sh/kernel/setup.c +++ b/arch/sh/kernel/setup.c @@ -43,6 +43,7 @@ #include <asm/smp.h> #include <asm/mmu_context.h> #include <asm/mmzone.h> +#include <asm/processor.h> #include <asm/sparsemem.h>

/* @@ -362,3 +363,57 @@ int test_mode_pin(int pin) { return sh_mv.mv_mode_pins() & pin; } + +void __init arch_cpu_finalize_init(void) +{ + char *p = &init_utsname()->machine[2]; /* "sh" */ + + select_idle_routine(); + + current_cpu_data.loops_per_jiffy = loops_per_jiffy; + + switch (current_cpu_data.family) { + case CPU_FAMILY_SH2: + *p++ = '2'; + break; + case CPU_FAMILY_SH2A: + *p++ = '2'; + *p++ = 'a'; + break; + case CPU_FAMILY_SH3: + *p++ = '3'; + break; + case CPU_FAMILY_SH4: + *p++ = '4'; + break; + case CPU_FAMILY_SH4A: + *p++ = '4'; + *p++ = 'a'; + break; + case CPU_FAMILY_SH4AL_DSP: + *p++ = '4'; + *p++ = 'a'; + *p++ = 'l'; + *p++ = '-'; + *p++ = 'd'; + *p++ = 's'; + *p++ = 'p'; + break; + case CPU_FAMILY_UNKNOWN: + /* + * Specifically use CPU_FAMILY_UNKNOWN rather than + * default:, so we're able to have the compiler whine + * about unhandled enumerations. + */ + break; + } + + pr_info("CPU: %s\n", get_cpu_subtype(&current_cpu_data)); + +#ifndef __LITTLE_ENDIAN__ + /* 'eb' means 'Endian Big' */ + *p++ = 'e'; + *p++ = 'b'; +#endif + *p = '\0'; +} diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index 8cb5bb020b4b..881f6a849148 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -52,6 +52,7 @@ config SPARC config SPARC32 def_bool !64BIT select ARCH_32BIT_OFF_T + select ARCH_HAS_CPU_FINALIZE_INIT if !SMP select ARCH_HAS_SYNC_DMA_FOR_CPU select GENERIC_ATOMIC64 select CLZ_TAB diff --git a/arch/sparc/include/asm/bugs.h b/arch/sparc/include/asm/bugs.h deleted file mode 100644 index 02fa369b9c21..000000000000 --- a/arch/sparc/include/asm/bugs.h +++ /dev/null @@ -1,18 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* include/asm/bugs.h: Sparc probes for various bugs. - * - * Copyright (C) 1996, 2007 David S. Miller (davem@davemloft.net) - */ - -#ifdef CONFIG_SPARC32 -#include <asm/cpudata.h> -#endif - -extern unsigned long loops_per_jiffy; - -static void __init check_bugs(void) -{ -#if defined(CONFIG_SPARC32) && !defined(CONFIG_SMP) - cpu_data(0).udelay_val = loops_per_jiffy; -#endif -} diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c index afe1592a6d08..4373c1d64ab8 100644 --- a/arch/sparc/kernel/setup_32.c +++ b/arch/sparc/kernel/setup_32.c @@ -422,3 +422,10 @@ static int __init topology_init(void) }

subsys_initcall(topology_init); + +#if defined(CONFIG_SPARC32) && !defined(CONFIG_SMP) +void __init arch_cpu_finalize_init(void) +{ + cpu_data(0).udelay_val = loops_per_jiffy; +} +#endif diff --git a/arch/um/Kconfig b/arch/um/Kconfig index c56d3526a3bd..468a5d63ef26 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -5,6 +5,7 @@ menu "UML-specific options" config UML bool default y + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_KCOV select ARCH_NO_PREEMPT select HAVE_ARCH_AUDITSYSCALL diff --git a/arch/um/include/asm/bugs.h b/arch/um/include/asm/bugs.h deleted file mode 100644 index 4473942a0839..000000000000 --- a/arch/um/include/asm/bugs.h +++ /dev/null @@ -1,7 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __UM_BUGS_H -#define __UM_BUGS_H - -void check_bugs(void); - -#endif diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 640c8e178502..004ef4ebb57d 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -3,6 +3,7 @@ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) */

+#include <linux/cpu.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/mm.h> @@ -353,7 +354,7 @@ void __init setup_arch(char **cmdline_p) setup_hostinfo(host_info, sizeof host_info); }

-void __init check_bugs(void) +void __init arch_cpu_finalize_init(void) { arch_check_bugs(); os_check_bugs(); diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6002252692af..df0a3a1b08ae 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -60,6 +60,7 @@ config X86 select ARCH_CLOCKSOURCE_DATA select ARCH_CLOCKSOURCE_INIT select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI + select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE @@ -2500,6 +2501,25 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK def_bool y depends on X86_64 || X86_PAE

+config GDS_FORCE_MITIGATION + bool "Force GDS Mitigation" + depends on CPU_SUP_INTEL + default n + help + Gather Data Sampling (GDS) is a hardware vulnerability which allows + unprivileged speculative access to data which was previously stored in + vector registers. + + This option is equivalent to setting gather_data_sampling=force on the + command line. The microcode mitigation is used if present, otherwise + AVX is disabled as a mitigation. On affected systems that are missing + the microcode any userspace code that unconditionally uses AVX will + break with this option set. + + Setting this option on systems not vulnerable to GDS has no effect. + + If in doubt, say N. + config ARCH_ENABLE_HUGEPAGE_MIGRATION def_bool y depends on X86_64 && HUGETLB_PAGE && MIGRATION diff --git a/arch/x86/include/asm/bugs.h b/arch/x86/include/asm/bugs.h index 794eb2129bc6..6554ddb2ad49 100644 --- a/arch/x86/include/asm/bugs.h +++ b/arch/x86/include/asm/bugs.h @@ -4,8 +4,6 @@

#include <asm/processor.h>

-extern void check_bugs(void); - #if defined(CONFIG_CPU_SUP_INTEL) void check_mpx_erratum(struct cpuinfo_x86 *c); #else diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 619c1f80a2ab..4466a47b7608 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -30,6 +30,8 @@ enum cpuid_leafs CPUID_7_ECX, CPUID_8000_0007_EBX, CPUID_7_EDX, + CPUID_8000_001F_EAX, + CPUID_8000_0021_EAX, };

#ifdef CONFIG_X86_FEATURE_NAMES @@ -88,8 +90,10 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \ REQUIRED_MASK_CHECK || \ - BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + BUILD_BUG_ON_ZERO(NCAPINTS != 21))

#define DISABLED_MASK_BIT_SET(feature_bit) \ ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ @@ -111,8 +115,10 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \ DISABLED_MASK_CHECK || \ - BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + BUILD_BUG_ON_ZERO(NCAPINTS != 21))

#define cpu_has(c, bit) \ (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 3e360dc07bae..f42286e9a2b1 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -13,8 +13,8 @@ /* * Defines x86 CPU feature bits */ -#define NCAPINTS 19 /* N 32-bit words worth of info */ -#define NBUGINTS 1 /* N 32-bit bug flags */ +#define NCAPINTS 21 /* N 32-bit words worth of info */ +#define NBUGINTS 2 /* N 32-bit bug flags */

/* * Note: If the comment begins with a quoted string, that string is used @@ -96,7 +96,7 @@ #define X86_FEATURE_SYSCALL32 ( 3*32+14) /* "" syscall in IA32 userspace */ #define X86_FEATURE_SYSENTER32 ( 3*32+15) /* "" sysenter in IA32 userspace */ #define X86_FEATURE_REP_GOOD ( 3*32+16) /* REP microcode works well */ -#define X86_FEATURE_SME_COHERENT ( 3*32+17) /* "" AMD hardware-enforced cache coherency */ +/* FREE! ( 3*32+17) */ #define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) /* "" LFENCE synchronizes RDTSC */ #define X86_FEATURE_ACC_POWER ( 3*32+19) /* AMD Accumulated Power Mechanism */ #define X86_FEATURE_NOPL ( 3*32+20) /* The NOPL (0F 1F) instructions */ @@ -201,7 +201,7 @@ #define X86_FEATURE_INVPCID_SINGLE ( 7*32+ 7) /* Effectively INVPCID && CR4.PCIDE=1 */ #define X86_FEATURE_HW_PSTATE ( 7*32+ 8) /* AMD HW-PState */ #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */ -#define X86_FEATURE_SME ( 7*32+10) /* AMD Secure Memory Encryption */ +/* FREE! ( 7*32+10) */ #define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */ #define X86_FEATURE_KERNEL_IBRS ( 7*32+12) /* "" Set/clear IBRS on kernel entry/exit */ #define X86_FEATURE_RSB_VMEXIT ( 7*32+13) /* "" Fill RSB on VM-Exit */ @@ -211,7 +211,7 @@ #define X86_FEATURE_SSBD ( 7*32+17) /* Speculative Store Bypass Disable */ #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */ #define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* "" Fill RSB on context switches */ -#define X86_FEATURE_SEV ( 7*32+20) /* AMD Secure Encrypted Virtualization */ +/* FREE! ( 7*32+20) */ #define X86_FEATURE_USE_IBPB ( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */ #define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */ @@ -375,6 +375,13 @@ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */

+/* AMD-defined memory encryption features, CPUID level 0x8000001f (EAX), word 19 */ +#define X86_FEATURE_SME (19*32+ 0) /* AMD Secure Memory Encryption */ +#define X86_FEATURE_SEV (19*32+ 1) /* AMD Secure Encrypted Virtualization */ +#define X86_FEATURE_VM_PAGE_FLUSH (19*32+ 2) /* "" VM Page Flush MSR is supported */ +#define X86_FEATURE_SEV_ES (19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */ +#define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ + /* * BUG word(s) */ @@ -415,5 +422,6 @@ #define X86_BUG_RETBLEED X86_BUG(26) /* CPU is affected by RETBleed */ #define X86_BUG_EIBRS_PBRSB X86_BUG(27) /* EIBRS is vulnerable to Post Barrier RSB Predictions */ #define X86_BUG_MMIO_UNKNOWN X86_BUG(28) /* CPU is too old and its MMIO Stale Data status is unknown */ +#define X86_BUG_GDS X86_BUG(29) /* CPU is affected by Gather Data Sampling */

#endif /* _ASM_X86_CPUFEATURES_H */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index a5ea841cc6d2..8453260f6d9f 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -84,6 +84,8 @@ #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP) #define DISABLED_MASK17 0 #define DISABLED_MASK18 0 -#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define DISABLED_MASK19 0 +#define DISABLED_MASK20 0 +#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)

#endif /* _ASM_X86_DISABLED_FEATURES_H */ diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 5ed702e2c55f..330841bad616 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -41,7 +41,7 @@ extern int dump_fpu(struct pt_regs *ptregs, struct user_i387_struct *fpstate); extern void fpu__init_cpu(void); extern void fpu__init_system_xstate(void); extern void fpu__init_cpu_xstate(void); -extern void fpu__init_system(struct cpuinfo_x86 *c); +extern void fpu__init_system(void); extern void fpu__init_check_bugs(void); extern void fpu__resume_cpu(void); extern u64 fpu__get_supported_xfeatures_mask(void); diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 848ce43b9040..190c5ca537e9 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -77,6 +77,8 @@ early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; static inline int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }

+static inline void mem_encrypt_init(void) { } + #define __bss_decrypted

#endif /* CONFIG_AMD_MEM_ENCRYPT */ diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index f3fa903c5b29..7137256f2c31 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -147,6 +147,15 @@ * Not susceptible to Post-Barrier * Return Stack Buffer Predictions. */ +#define ARCH_CAP_GDS_CTRL BIT(25) /* + * CPU is vulnerable to Gather + * Data Sampling (GDS) and + * has controls for mitigation. + */ +#define ARCH_CAP_GDS_NO BIT(26) /* + * CPU is not vulnerable to Gather + * Data Sampling (GDS). + */

#define MSR_IA32_FLUSH_CMD 0x0000010b #define L1D_FLUSH BIT(0) /* @@ -165,6 +174,8 @@ #define MSR_IA32_MCU_OPT_CTRL 0x00000123 #define RNGDS_MITG_DIS BIT(0) #define FB_CLEAR_DIS BIT(3) /* CPU Fill buffer clear disable */ +#define GDS_MITG_DIS BIT(4) /* Disable GDS mitigation */ +#define GDS_MITG_LOCKED BIT(5) /* GDS mitigation locked */

#define MSR_IA32_SYSENTER_CS 0x00000174 #define MSR_IA32_SYSENTER_ESP 0x00000175 @@ -484,6 +495,7 @@ #define MSR_AMD64_ICIBSEXTDCTL 0xc001103c #define MSR_AMD64_IBSOPDATA4 0xc001103d #define MSR_AMD64_IBS_REG_COUNT_MAX 8 /* includes MSR_AMD64_IBSBRTARGET */ +#define MSR_AMD64_VM_PAGE_FLUSH 0xc001011e #define MSR_AMD64_SEV 0xc0010131 #define MSR_AMD64_SEV_ENABLED_BIT 0 #define MSR_AMD64_SEV_ENABLED BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT) diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h index 6847d85400a8..fb3d81347e33 100644 --- a/arch/x86/include/asm/required-features.h +++ b/arch/x86/include/asm/required-features.h @@ -101,6 +101,8 @@ #define REQUIRED_MASK16 0 #define REQUIRED_MASK17 0 #define REQUIRED_MASK18 0 -#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define REQUIRED_MASK19 0 +#define REQUIRED_MASK20 0 +#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)

#endif /* _ASM_X86_REQUIRED_FEATURES_H */ diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 3f182c06b305..11f09df72f51 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -663,7 +663,7 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) * If BIOS has not enabled SME then don't advertise the * SME feature (set in scattered.c). * For SEV: If BIOS has not enabled SEV then don't advertise the - * SEV feature (set in scattered.c). + * SEV and SEV_ES feature (set in scattered.c). * * In all cases, since support for SME and SEV requires long mode, * don't advertise the feature under CONFIG_X86_32. @@ -694,6 +694,7 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) setup_clear_cpu_cap(X86_FEATURE_SME); clear_sev: setup_clear_cpu_cap(X86_FEATURE_SEV); + setup_clear_cpu_cap(X86_FEATURE_SEV_ES); } }

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 75ca28bb267c..48ae44cf7795 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -9,7 +9,6 @@ * - Andrew D. Balsa (code cleanup). */ #include <linux/init.h> -#include <linux/utsname.h> #include <linux/cpu.h> #include <linux/module.h> #include <linux/nospec.h> @@ -25,9 +24,7 @@ #include <asm/msr.h> #include <asm/vmx.h> #include <asm/paravirt.h> -#include <asm/alternative.h> #include <asm/pgtable.h> -#include <asm/set_memory.h> #include <asm/intel-family.h> #include <asm/e820/api.h> #include <asm/hypervisor.h> @@ -47,6 +44,7 @@ static void __init md_clear_select_mitigation(void); static void __init taa_select_mitigation(void); static void __init mmio_select_mitigation(void); static void __init srbds_select_mitigation(void); +static void __init gds_select_mitigation(void);

/* The base value of the SPEC_CTRL MSR without task-specific bits set */ u64 x86_spec_ctrl_base; @@ -115,21 +113,8 @@ EXPORT_SYMBOL_GPL(mds_idle_clear); DEFINE_STATIC_KEY_FALSE(mmio_stale_data_clear); EXPORT_SYMBOL_GPL(mmio_stale_data_clear);

-void __init check_bugs(void) +void __init cpu_select_mitigations(void) { - identify_boot_cpu(); - - /* - * identify_boot_cpu() initialized SMT support information, let the - * core code know. - */ - cpu_smt_check_topology(); - - if (!IS_ENABLED(CONFIG_SMP)) { - pr_info("CPU: "); - print_cpu_info(&boot_cpu_data); - } - /* * Read the SPEC_CTRL MSR to account for reserved bits which may * have unknown values. AMD64_LS_CFG MSR is cached in the early AMD @@ -165,39 +150,7 @@ void __init check_bugs(void) l1tf_select_mitigation(); md_clear_select_mitigation(); srbds_select_mitigation(); - - arch_smt_update(); - -#ifdef CONFIG_X86_32 - /* - * Check whether we are able to run this kernel safely on SMP. - * - * - i386 is no longer supported. - * - In order to run on anything without a TSC, we need to be - * compiled for a i486. - */ - if (boot_cpu_data.x86 < 4) - panic("Kernel requires i486+ for 'invlpg' and other features"); - - init_utsname()->machine[1] = - '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); - alternative_instructions(); - - fpu__init_check_bugs(); -#else /* CONFIG_X86_64 */ - alternative_instructions(); - - /* - * Make sure the first 2MB area is not mapped by huge pages - * There are typically fixed size MTRRs in there and overlapping - * MTRRs into large pages causes slow downs. - * - * Right now we don't do that with gbpages because there seems - * very little benefit for that case. - */ - if (!direct_gbpages) - set_memory_4k((unsigned long)__va(0), 1); -#endif + gds_select_mitigation(); }

/* @@ -648,6 +601,149 @@ static int __init srbds_parse_cmdline(char *str) } early_param("srbds", srbds_parse_cmdline);

+#undef pr_fmt +#define pr_fmt(fmt) "GDS: " fmt + +enum gds_mitigations { + GDS_MITIGATION_OFF, + GDS_MITIGATION_UCODE_NEEDED, + GDS_MITIGATION_FORCE, + GDS_MITIGATION_FULL, + GDS_MITIGATION_FULL_LOCKED, + GDS_MITIGATION_HYPERVISOR, +}; + +#if IS_ENABLED(CONFIG_GDS_FORCE_MITIGATION) +static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FORCE; +#else +static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FULL; +#endif + +static const char * const gds_strings[] = { + [GDS_MITIGATION_OFF] = "Vulnerable", + [GDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode", + [GDS_MITIGATION_FORCE] = "Mitigation: AVX disabled, no microcode", + [GDS_MITIGATION_FULL] = "Mitigation: Microcode", + [GDS_MITIGATION_FULL_LOCKED] = "Mitigation: Microcode (locked)", + [GDS_MITIGATION_HYPERVISOR] = "Unknown: Dependent on hypervisor status", +}; + +bool gds_ucode_mitigated(void) +{ + return (gds_mitigation == GDS_MITIGATION_FULL || + gds_mitigation == GDS_MITIGATION_FULL_LOCKED); +} +EXPORT_SYMBOL_GPL(gds_ucode_mitigated); + +void update_gds_msr(void) +{ + u64 mcu_ctrl_after; + u64 mcu_ctrl; + + switch (gds_mitigation) { + case GDS_MITIGATION_OFF: + rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); + mcu_ctrl |= GDS_MITG_DIS; + break; + case GDS_MITIGATION_FULL_LOCKED: + /* + * The LOCKED state comes from the boot CPU. APs might not have + * the same state. Make sure the mitigation is enabled on all + * CPUs. + */ + case GDS_MITIGATION_FULL: + rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); + mcu_ctrl &= ~GDS_MITG_DIS; + break; + case GDS_MITIGATION_FORCE: + case GDS_MITIGATION_UCODE_NEEDED: + case GDS_MITIGATION_HYPERVISOR: + return; + }; + + wrmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); + + /* + * Check to make sure that the WRMSR value was not ignored. Writes to + * GDS_MITG_DIS will be ignored if this processor is locked but the boot + * processor was not. + */ + rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl_after); + WARN_ON_ONCE(mcu_ctrl != mcu_ctrl_after); +} + +static void __init gds_select_mitigation(void) +{ + u64 mcu_ctrl; + + if (!boot_cpu_has_bug(X86_BUG_GDS)) + return; + + if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { + gds_mitigation = GDS_MITIGATION_HYPERVISOR; + goto out; + } + + if (cpu_mitigations_off()) + gds_mitigation = GDS_MITIGATION_OFF; + /* Will verify below that mitigation _can_ be disabled */ + + /* No microcode */ + if (!(x86_read_arch_cap_msr() & ARCH_CAP_GDS_CTRL)) { + if (gds_mitigation == GDS_MITIGATION_FORCE) { + /* + * This only needs to be done on the boot CPU so do it + * here rather than in update_gds_msr() + */ + setup_clear_cpu_cap(X86_FEATURE_AVX); + pr_warn("Microcode update needed! Disabling AVX as mitigation.\n"); + } else { + gds_mitigation = GDS_MITIGATION_UCODE_NEEDED; + } + goto out; + } + + /* Microcode has mitigation, use it */ + if (gds_mitigation == GDS_MITIGATION_FORCE) + gds_mitigation = GDS_MITIGATION_FULL; + + rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); + if (mcu_ctrl & GDS_MITG_LOCKED) { + if (gds_mitigation == GDS_MITIGATION_OFF) + pr_warn("Mitigation locked. Disable failed.\n"); + + /* + * The mitigation is selected from the boot CPU. All other CPUs + * _should_ have the same state. If the boot CPU isn't locked + * but others are then update_gds_msr() will WARN() of the state + * mismatch. If the boot CPU is locked update_gds_msr() will + * ensure the other CPUs have the mitigation enabled. + */ + gds_mitigation = GDS_MITIGATION_FULL_LOCKED; + } + + update_gds_msr(); +out: + pr_info("%s\n", gds_strings[gds_mitigation]); +} + +static int __init gds_parse_cmdline(char *str) +{ + if (!str) + return -EINVAL; + + if (!boot_cpu_has_bug(X86_BUG_GDS)) + return 0; + + if (!strcmp(str, "off")) + gds_mitigation = GDS_MITIGATION_OFF; + else if (!strcmp(str, "force")) + gds_mitigation = GDS_MITIGATION_FORCE; + + return 0; +} +early_param("gather_data_sampling", gds_parse_cmdline); + #undef pr_fmt #define pr_fmt(fmt) "Spectre V1 : " fmt

@@ -2207,6 +2303,11 @@ static ssize_t retbleed_show_state(char *buf) return sprintf(buf, "%s\n", retbleed_strings[retbleed_mitigation]); }

+static ssize_t gds_show_state(char *buf) +{ + return sysfs_emit(buf, "%s\n", gds_strings[gds_mitigation]); +} + static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr, char *buf, unsigned int bug) { @@ -2256,6 +2357,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr case X86_BUG_RETBLEED: return retbleed_show_state(buf);

+ case X86_BUG_GDS: + return gds_show_state(buf); + default: break; } @@ -2320,4 +2424,9 @@ ssize_t cpu_show_retbleed(struct device *dev, struct device_attribute *attr, cha { return cpu_show_common(dev, attr, buf, X86_BUG_RETBLEED); } + +ssize_t cpu_show_gds(struct device *dev, struct device_attribute *attr, char *buf) +{ + return cpu_show_common(dev, attr, buf, X86_BUG_GDS); +} #endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c8ccf5bfd534..fcfe891c1e8e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -17,11 +17,16 @@ #include <linux/init.h> #include <linux/kprobes.h> #include <linux/kgdb.h> +#include <linux/mem_encrypt.h> #include <linux/smp.h> +#include <linux/cpu.h> #include <linux/io.h> #include <linux/syscore_ops.h>

#include <asm/stackprotector.h> +#include <linux/utsname.h> + +#include <asm/alternative.h> #include <asm/perf_event.h> #include <asm/mmu_context.h> #include <asm/archrandom.h> @@ -57,6 +62,7 @@ #ifdef CONFIG_X86_LOCAL_APIC #include <asm/uv/uv.h> #endif +#include <asm/set_memory.h>

#include "cpu.h"

@@ -961,6 +967,12 @@ void get_cpu_cap(struct cpuinfo_x86 *c) if (c->extended_cpuid_level >= 0x8000000a) c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);

+ if (c->extended_cpuid_level >= 0x8000001f) + c->x86_capability[CPUID_8000_001F_EAX] = cpuid_eax(0x8000001f); + + if (c->extended_cpuid_level >= 0x80000021) + c->x86_capability[CPUID_8000_0021_EAX] = cpuid_eax(0x80000021); + init_scattered_cpuid_features(c); init_speculation_control(c); init_cqm(c); @@ -1123,6 +1135,12 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = { #define MMIO_SBDS BIT(2) /* CPU is affected by RETbleed, speculating where you would not expect it */ #define RETBLEED BIT(3) +/* CPU is affected by SMT (cross-thread) return predictions */ +#define SMT_RSB BIT(4) +/* CPU is affected by SRSO */ +#define SRSO BIT(5) +/* CPU is affected by GDS */ +#define GDS BIT(6)

static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS), @@ -1135,19 +1153,21 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { VULNBL_INTEL_STEPPINGS(BROADWELL_X, X86_STEPPING_ANY, MMIO), VULNBL_INTEL_STEPPINGS(BROADWELL, X86_STEPPING_ANY, SRBDS), VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), - VULNBL_INTEL_STEPPINGS(SKYLAKE_X, X86_STEPPING_ANY, MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(SKYLAKE_X, X86_STEPPING_ANY, MMIO | RETBLEED | GDS), VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), - VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), - VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED | GDS), VULNBL_INTEL_STEPPINGS(CANNONLAKE_L, X86_STEPPING_ANY, RETBLEED), - VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), - VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO), - VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO), - VULNBL_INTEL_STEPPINGS(COMETLAKE, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), + VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO | GDS), + VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO | GDS), + VULNBL_INTEL_STEPPINGS(COMETLAKE, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO | RETBLEED), - VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), + VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(TIGERLAKE_L, X86_STEPPING_ANY, GDS), + VULNBL_INTEL_STEPPINGS(TIGERLAKE, X86_STEPPING_ANY, GDS), VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), - VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED | GDS), VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS), VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO), VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS), @@ -1273,6 +1293,16 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) !(ia32_cap & ARCH_CAP_PBRSB_NO)) setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);

+ /* + * Check if CPU is vulnerable to GDS. If running in a virtual machine on + * an affected processor, the VMM may have disabled the use of GATHER by + * disabling AVX2. The only way to do this in HW is to clear XCR0[2], + * which means that AVX will be disabled. + */ + if (cpu_matches(cpu_vuln_blacklist, GDS) && !(ia32_cap & ARCH_CAP_GDS_NO) && + boot_cpu_has(X86_FEATURE_AVX)) + setup_force_cpu_bug(X86_BUG_GDS); + if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN)) return;

@@ -1358,8 +1388,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)

cpu_set_bug_bits(c);

- fpu__init_system(c); - #ifdef CONFIG_X86_32 /* * Regardless of whether PCID is enumerated, the SDM says @@ -1751,6 +1779,8 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c) validate_apic_and_package_id(c); x86_spec_ctrl_setup_ap(); update_srbds_msr(); + if (boot_cpu_has_bug(X86_BUG_GDS)) + update_gds_msr(); }

static __init int setup_noclflush(char *arg) @@ -2049,8 +2079,6 @@ void cpu_init(void) clear_all_debug_regs(); dbg_restore_debug_regs();

- fpu__init_cpu(); - if (is_uv_system()) uv_cpu_init();

@@ -2108,8 +2136,6 @@ void cpu_init(void) clear_all_debug_regs(); dbg_restore_debug_regs();

- fpu__init_cpu(); - load_fixmap_gdt(cpu); } #endif @@ -2156,3 +2182,69 @@ void arch_smt_update(void) /* Check whether IPI broadcasting can be enabled */ apic_smt_update(); } + +void __init arch_cpu_finalize_init(void) +{ + identify_boot_cpu(); + + /* + * identify_boot_cpu() initialized SMT support information, let the + * core code know. + */ + cpu_smt_check_topology(); + + if (!IS_ENABLED(CONFIG_SMP)) { + pr_info("CPU: "); + print_cpu_info(&boot_cpu_data); + } + + cpu_select_mitigations(); + + arch_smt_update(); + + if (IS_ENABLED(CONFIG_X86_32)) { + /* + * Check whether this is a real i386 which is not longer + * supported and fixup the utsname. + */ + if (boot_cpu_data.x86 < 4) + panic("Kernel requires i486+ for 'invlpg' and other features"); + + init_utsname()->machine[1] = + '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); + } + + /* + * Must be before alternatives because it might set or clear + * feature bits. + */ + fpu__init_system(); + fpu__init_cpu(); + + alternative_instructions(); + + if (IS_ENABLED(CONFIG_X86_64)) { + /* + * Make sure the first 2MB area is not mapped by huge pages + * There are typically fixed size MTRRs in there and overlapping + * MTRRs into large pages causes slow downs. + * + * Right now we don't do that with gbpages because there seems + * very little benefit for that case. + */ + if (!direct_gbpages) + set_memory_4k((unsigned long)__va(0), 1); + } else { + fpu__init_check_bugs(); + } + + /* + * This needs to be called before any devices perform DMA + * operations that might use the SWIOTLB bounce buffers. It will + * mark the bounce buffers as decrypted so that their usage will + * not cause "plain-text" data to be decrypted when accessed. It + * must be called after late_time_init() so that Hyper-V x86/x64 + * hypercalls work when the SWIOTLB bounce buffers are decrypted. + */ + mem_encrypt_init(); +} diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 4d04c127c4a7..8a64520b5310 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -76,9 +76,11 @@ extern void detect_ht(struct cpuinfo_x86 *c); extern void check_null_seg_clears_base(struct cpuinfo_x86 *c);

unsigned int aperfmperf_get_khz(int cpu); +void cpu_select_mitigations(void);

extern void x86_spec_ctrl_setup_ap(void); extern void update_srbds_msr(void); +extern void update_gds_msr(void);

extern u64 x86_read_arch_cap_msr(void);

diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index a03e309a0ac5..37f716eaf0e6 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -40,9 +40,6 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 }, { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 }, { X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 }, - { X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 }, - { X86_FEATURE_SEV, CPUID_EAX, 1, 0x8000001f, 0 }, - { X86_FEATURE_SME_COHERENT, CPUID_EAX, 10, 0x8000001f, 0 }, { 0, 0, 0, 0, 0 } };

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 17d092eb1934..5e710ad6a3c0 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -50,7 +50,7 @@ void fpu__init_cpu(void) fpu__init_cpu_xstate(); }

-static bool fpu__probe_without_cpuid(void) +static bool __init fpu__probe_without_cpuid(void) { unsigned long cr0; u16 fsw, fcw; @@ -68,7 +68,7 @@ static bool fpu__probe_without_cpuid(void) return fsw == 0 && (fcw & 0x103f) == 0x003f; }

-static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) +static void __init fpu__init_system_early_generic(void) { if (!boot_cpu_has(X86_FEATURE_CPUID) && !test_bit(X86_FEATURE_FPU, (unsigned long *)cpu_caps_cleared)) { @@ -290,10 +290,10 @@ static void __init fpu__init_parse_early_param(void) * Called on the boot CPU once per system bootup, to set up the initial * FPU state that is later cloned into all processes: */ -void __init fpu__init_system(struct cpuinfo_x86 *c) +void __init fpu__init_system(void) { fpu__init_parse_early_param(); - fpu__init_system_early_generic(c); + fpu__init_system_early_generic();

/* * The FPU has to be operational for some of the diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 45e5ecb43393..d6a8efff9c61 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -235,6 +235,7 @@ static void notrace start_secondary(void *unused) #endif load_current_idt(); cpu_init(); + fpu__init_cpu(); rcu_cpu_starting(raw_smp_processor_id()); x86_cpuinit.early_percpu_clock_init(); preempt_disable(); diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 7dec43b2c420..defae8082789 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -53,6 +53,7 @@ static const struct cpuid_reg reverse_cpuid[] = { [CPUID_7_ECX] = { 7, 0, CPUID_ECX}, [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX}, [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, + [CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX}, };

static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d152afdfa8b4..2ee3da99bc1d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -226,6 +226,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {

u64 __read_mostly host_xcr0;

+extern bool gds_ucode_mitigated(void); + struct kmem_cache *x86_fpu_cache; EXPORT_SYMBOL_GPL(x86_fpu_cache);

@@ -1409,6 +1411,9 @@ static u64 kvm_get_arch_capabilities(void) /* Guests don't need to know "Fill buffer clear control" exists */ data &= ~ARCH_CAP_FB_CLEAR_CTRL;

+ if (!boot_cpu_has_bug(X86_BUG_GDS) || gds_ucode_mitigated()) + data |= ARCH_CAP_GDS_NO; + return data; }

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 38e6798ce44f..086b274fa60f 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -7,6 +7,7 @@ #include <linux/swapops.h> #include <linux/kmemleak.h> #include <linux/sched/task.h> +#include <linux/sched/mm.h>

#include <asm/set_memory.h> #include <asm/cpu_device_id.h> @@ -26,6 +27,7 @@ #include <asm/cpufeature.h> #include <asm/pti.h> #include <asm/text-patching.h> +#include <asm/paravirt.h>

/* * We need to define the tracepoints somewhere, and tlb.c @@ -735,9 +737,12 @@ void __init poking_init(void) spinlock_t *ptl; pte_t *ptep;

- poking_mm = copy_init_mm(); + poking_mm = mm_alloc(); BUG_ON(!poking_mm);

+ /* Xen PV guests need the PGD to be pinned. */ + paravirt_arch_dup_mmap(NULL, poking_mm); + /* * Randomize the poking address, but make sure that the following page * will be mapped at the same PMD. We need 2 pages, so find space for 3, diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index 928fbe63c96f..3a0a27d94c05 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -28,6 +28,7 @@ #include <asm/desc.h> #include <asm/pgtable.h> #include <asm/cpu.h> +#include <asm/fpu/internal.h>

#include <xen/interface/xen.h> #include <xen/interface/vcpu.h> @@ -61,6 +62,7 @@ static void cpu_bringup(void)

cr4_init(); cpu_init(); + fpu__init_cpu(); touch_softlockup_watchdog(); preempt_disable();

diff --git a/arch/xtensa/include/asm/bugs.h b/arch/xtensa/include/asm/bugs.h deleted file mode 100644 index 69b29d198249..000000000000 --- a/arch/xtensa/include/asm/bugs.h +++ /dev/null @@ -1,18 +0,0 @@ -/* - * include/asm-xtensa/bugs.h - * - * This is included by init/main.c to check for architecture-dependent bugs. - * - * Xtensa processors don't have any bugs. :) - * - * This file is subject to the terms and conditions of the GNU General - * Public License. See the file "COPYING" in the main directory of - * this archive for more details. - */ - -#ifndef _XTENSA_BUGS_H -#define _XTENSA_BUGS_H - -static void check_bugs(void) { } - -#endif /* _XTENSA_BUGS_H */ diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 980e9a76e172..5e0c1fd27720 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -581,6 +581,12 @@ ssize_t __weak cpu_show_retbleed(struct device *dev, return sysfs_emit(buf, "Not affected\n"); }

+ssize_t __weak cpu_show_gds(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "Not affected\n"); +} + static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL); @@ -592,6 +598,7 @@ static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL); static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL); static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL); static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL); +static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL);

static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_meltdown.attr, @@ -605,6 +612,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_srbds.attr, &dev_attr_mmio_stale_data.attr, &dev_attr_retbleed.attr, + &dev_attr_gather_data_sampling.attr, NULL };

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index a3078755939e..c3eadac893d8 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -389,7 +389,7 @@ static void xenvif_get_requests(struct xenvif_queue *queue, struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops; struct xen_netif_tx_request *txp = first;

- nr_slots = shinfo->nr_frags + 1; + nr_slots = shinfo->nr_frags + frag_overflow + 1;

copy_count(skb) = 0; XENVIF_TX_CB(skb)->split_mask = 0; @@ -455,8 +455,8 @@ static void xenvif_get_requests(struct xenvif_queue *queue, } }

- for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; - shinfo->nr_frags++, gop++) { + for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS; + shinfo->nr_frags++, gop++, nr_slots--) { index = pending_index(queue->pending_cons++); pending_idx = queue->pending_ring[index]; xenvif_tx_create_map_op(queue, pending_idx, txp, @@ -469,12 +469,12 @@ static void xenvif_get_requests(struct xenvif_queue *queue, txp++; }

- if (frag_overflow) { + if (nr_slots > 0) {

shinfo = skb_shinfo(nskb); frags = shinfo->frags;

- for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow; + for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; shinfo->nr_frags++, txp++, gop++) { index = pending_index(queue->pending_cons++); pending_idx = queue->pending_ring[index]; @@ -485,6 +485,11 @@ static void xenvif_get_requests(struct xenvif_queue *queue, }

skb_shinfo(skb)->frag_list = nskb; + } else if (nskb) { + /* A frag_list skb was allocated but it is no longer needed + * because enough slots were converted to copy ops above. + */ + kfree_skb(nskb); }

(*copy_ops) = cop - queue->tx_copy_ops; diff --git a/include/asm-generic/bugs.h b/include/asm-generic/bugs.h deleted file mode 100644 index 69021830f078..000000000000 --- a/include/asm-generic/bugs.h +++ /dev/null @@ -1,11 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __ASM_GENERIC_BUGS_H -#define __ASM_GENERIC_BUGS_H -/* - * This file is included by 'init/main.c' to check for - * architecture-dependent bugs. - */ - -static inline void check_bugs(void) { } - -#endif /* __ASM_GENERIC_BUGS_H */ diff --git a/include/linux/cpu.h b/include/linux/cpu.h index b42e9c413447..782491dd1999 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -193,6 +193,12 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void arch_cpu_idle_dead(void);

+#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT +void arch_cpu_finalize_init(void); +#else +static inline void arch_cpu_finalize_init(void) { } +#endif + int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 6f33a07858cf..853ab403e77b 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -53,6 +53,7 @@ extern void sched_dead(struct task_struct *p); void __noreturn do_task_dead(void); void __noreturn make_task_dead(int signr);

+extern void mm_cache_init(void); extern void proc_caches_init(void);

extern void fork_init(void); @@ -93,7 +94,6 @@ extern long _do_fork(struct kernel_clone_args *kargs); extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs); extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); struct task_struct *fork_idle(int); -struct mm_struct *copy_init_mm(void); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);

diff --git a/init/main.c b/init/main.c index a17a111d9336..1db844b38810 100644 --- a/init/main.c +++ b/init/main.c @@ -93,10 +93,8 @@ #include <linux/cache.h> #include <linux/rodata_test.h> #include <linux/jump_label.h> -#include <linux/mem_encrypt.h>

#include <asm/io.h> -#include <asm/bugs.h> #include <asm/setup.h> #include <asm/sections.h> #include <asm/cacheflush.h> @@ -504,8 +502,6 @@ void __init __weak thread_stack_cache_init(void) } #endif

-void __init __weak mem_encrypt_init(void) { } - void __init __weak poking_init(void) { }

void __init __weak pgtable_cache_init(void) { } @@ -567,6 +563,7 @@ static void __init mm_init(void) init_espfix_bsp(); /* Should be run after espfix64 is set up. */ pti_init(); + mm_cache_init(); }

void __init __weak arch_call_rest_init(void) @@ -627,7 +624,7 @@ asmlinkage __visible void __init start_kernel(void) sort_main_extable(); trap_init(); mm_init(); - + poking_init(); ftrace_init();

/* trace_printk can be enabled here */ @@ -721,14 +718,6 @@ asmlinkage __visible void __init start_kernel(void) */ locking_selftest();

- /* - * This needs to be called before any devices perform DMA - * operations that might use the SWIOTLB bounce buffers. It will - * mark the bounce buffers as decrypted so that their usage will - * not cause "plain-text" data to be decrypted when accessed. - */ - mem_encrypt_init(); - #ifdef CONFIG_BLK_DEV_INITRD if (initrd_start && !initrd_below_start_ok && page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { @@ -745,6 +734,9 @@ asmlinkage __visible void __init start_kernel(void) late_time_init(); sched_clock_init(); calibrate_delay(); + + arch_cpu_finalize_init(); + pid_idr_init(); anon_vma_init(); #ifdef CONFIG_X86 @@ -771,9 +763,6 @@ asmlinkage __visible void __init start_kernel(void) taskstats_init_early(); delayacct_init();

- poking_init(); - check_bugs(); - acpi_subsystem_init(); arch_post_acpi_subsys_init(); sfi_init_late(); diff --git a/kernel/fork.c b/kernel/fork.c index 5b4a19682207..39134effb2bf 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2335,11 +2335,6 @@ struct task_struct *fork_idle(int cpu) return task; }

-struct mm_struct *copy_init_mm(void) -{ - return dup_mm(NULL, &init_mm); -} - /* * Ok, this is the main fork-routine. * @@ -2710,10 +2705,27 @@ static void sighand_ctor(void *data) init_waitqueue_head(&sighand->signalfd_wqh); }

-void __init proc_caches_init(void) +void __init mm_cache_init(void) { unsigned int mm_size;

+ /* + * The mm_cpumask is located at the end of mm_struct, and is + * dynamically sized based on the maximum CPU number this system + * can have, taking hotplug into account (nr_cpu_ids). + */ + mm_size = sizeof(struct mm_struct) + cpumask_size(); + + mm_cachep = kmem_cache_create_usercopy("mm_struct", + mm_size, ARCH_MIN_MMSTRUCT_ALIGN, + SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, + offsetof(struct mm_struct, saved_auxv), + sizeof_field(struct mm_struct, saved_auxv), + NULL); +} + +void __init proc_caches_init(void) +{ sighand_cachep = kmem_cache_create("sighand_cache", sizeof(struct sighand_struct), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU| @@ -2731,19 +2743,6 @@ void __init proc_caches_init(void) SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL);

- /* - * The mm_cpumask is located at the end of mm_struct, and is - * dynamically sized based on the maximum CPU number this system - * can have, taking hotplug into account (nr_cpu_ids). - */ - mm_size = sizeof(struct mm_struct) + cpumask_size(); - - mm_cachep = kmem_cache_create_usercopy("mm_struct", - mm_size, ARCH_MIN_MMSTRUCT_ALIGN, - SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, - offsetof(struct mm_struct, saved_auxv), - sizeof_field(struct mm_struct, saved_auxv), - NULL); vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC|SLAB_ACCOUNT); mmap_init(); nsproxy_cache_init(); diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h index 3efaf338d325..eea52cb0e6ab 100644 --- a/tools/arch/x86/include/asm/cpufeatures.h +++ b/tools/arch/x86/include/asm/cpufeatures.h @@ -13,8 +13,8 @@ /* * Defines x86 CPU feature bits */ -#define NCAPINTS 19 /* N 32-bit words worth of info */ -#define NBUGINTS 1 /* N 32-bit bug flags */ +#define NCAPINTS 20 /* N 32-bit words worth of info */ +#define NBUGINTS 2 /* N 32-bit bug flags */

/* * Note: If the comment begins with a quoted string, that string is used @@ -96,6 +96,7 @@ #define X86_FEATURE_SYSCALL32 ( 3*32+14) /* "" syscall in IA32 userspace */ #define X86_FEATURE_SYSENTER32 ( 3*32+15) /* "" sysenter in IA32 userspace */ #define X86_FEATURE_REP_GOOD ( 3*32+16) /* REP microcode works well */ +/* FREE! ( 3*32+17) */ #define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) /* "" LFENCE synchronizes RDTSC */ #define X86_FEATURE_ACC_POWER ( 3*32+19) /* AMD Accumulated Power Mechanism */ #define X86_FEATURE_NOPL ( 3*32+20) /* The NOPL (0F 1F) instructions */ @@ -199,7 +200,7 @@ #define X86_FEATURE_INVPCID_SINGLE ( 7*32+ 7) /* Effectively INVPCID && CR4.PCIDE=1 */ #define X86_FEATURE_HW_PSTATE ( 7*32+ 8) /* AMD HW-PState */ #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */ -#define X86_FEATURE_SME ( 7*32+10) /* AMD Secure Memory Encryption */ +/* FREE! ( 7*32+10) */ #define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */ #define X86_FEATURE_RETPOLINE ( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */ #define X86_FEATURE_RETPOLINE_LFENCE ( 7*32+13) /* "" Use LFENCEs for Spectre variant 2 */ @@ -209,7 +210,7 @@ #define X86_FEATURE_SSBD ( 7*32+17) /* Speculative Store Bypass Disable */ #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */ #define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* "" Fill RSB on context switches */ -#define X86_FEATURE_SEV ( 7*32+20) /* AMD Secure Encrypted Virtualization */ +/* FREE! ( 7*32+20) */ #define X86_FEATURE_USE_IBPB ( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */ #define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */ @@ -287,6 +288,7 @@ #define X86_FEATURE_RSB_VMEXIT_LITE (11*32+17) /* "" Fill RSB on VM-Exit when EIBRS is enabled */

/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ +#define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */

/* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */ @@ -328,6 +330,7 @@ #define X86_FEATURE_AVIC (15*32+13) /* Virtual Interrupt Controller */ #define X86_FEATURE_V_VMSAVE_VMLOAD (15*32+15) /* Virtual VMSAVE VMLOAD */ #define X86_FEATURE_VGIF (15*32+16) /* Virtual GIF */ +#define X86_FEATURE_SVME_ADDR_CHK (15*32+28) /* "" SVME addr check */

/* Intel-defined CPU features, CPUID level 0x00000007:0 (ECX), word 16 */ #define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/ @@ -367,6 +370,13 @@ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */

+/* AMD-defined memory encryption features, CPUID level 0x8000001f (EAX), word 19 */ +#define X86_FEATURE_SME (19*32+ 0) /* AMD Secure Memory Encryption */ +#define X86_FEATURE_SEV (19*32+ 1) /* AMD Secure Encrypted Virtualization */ +#define X86_FEATURE_VM_PAGE_FLUSH (19*32+ 2) /* "" VM Page Flush MSR is supported */ +#define X86_FEATURE_SEV_ES (19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */ +#define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ + /* * BUG word(s) */ diff --git a/tools/arch/x86/include/asm/disabled-features.h b/tools/arch/x86/include/asm/disabled-features.h index a5ea841cc6d2..f0f935f8d917 100644 --- a/tools/arch/x86/include/asm/disabled-features.h +++ b/tools/arch/x86/include/asm/disabled-features.h @@ -84,6 +84,7 @@ #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP) #define DISABLED_MASK17 0 #define DISABLED_MASK18 0 -#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define DISABLED_MASK19 0 +#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)

#endif /* _ASM_X86_DISABLED_FEATURES_H */ diff --git a/tools/arch/x86/include/asm/required-features.h b/tools/arch/x86/include/asm/required-features.h index 6847d85400a8..fa5700097f64 100644 --- a/tools/arch/x86/include/asm/required-features.h +++ b/tools/arch/x86/include/asm/required-features.h @@ -101,6 +101,7 @@ #define REQUIRED_MASK16 0 #define REQUIRED_MASK17 0 #define REQUIRED_MASK18 0 -#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define REQUIRED_MASK19 0 +#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)

#endif /* _ASM_X86_REQUIRED_FEATURES_H */