This series wires up getrandom() vDSO implementation on powerpc.
Tested on PPC32 on real hardware. Tested on PPC64 (both BE and LE) on QEMU:
Performance on powerpc 885: ~# ./vdso_test_getrandom bench-single vdso: 25000000 times in 62.938002291 seconds libc: 25000000 times in 535.581916866 seconds syscall: 25000000 times in 531.525042806 seconds
Performance on powerpc 8321: ~# ./vdso_test_getrandom bench-single vdso: 25000000 times in 16.899318858 seconds libc: 25000000 times in 131.050596522 seconds syscall: 25000000 times in 129.794790389 seconds
Performance on QEMU pseries: ~ # ./vdso_test_getrandom bench-single vdso: 25000000 times in 4.977777162 seconds libc: 25000000 times in 75.516749981 seconds syscall: 25000000 times in 86.842242014 seconds
In order to run selftests, some fixes are needed, see https://lore.kernel.org/linuxppc-dev/6c5da802e72befecfa09046c489aa45d934d611...
Those selftest fixes are independant and are not required to apply and use this series.
Changes in v3: - Rebased on recent random git tree (0c7e00e22c21) - Fixed build failures reported by robots around VM_DROPPABLE - Fixed crash on PPC64 due to clobbered r13 by not using r13 anymore (saving it was not enough for signals). - Split final patch in two, first for PPC32, second for PPC64 - Moved selftest fixes out of this series
Changes in v2: - Define VM_DROPPABLE for powerpc/32 - Fixes generic vDSO getrandom headers to enable CONFIG_COMPAT build. - Fixed size of generation counter - Fixed selftests to work on non x86 architectures
Christophe Leroy (5): mm: Define VM_DROPPABLE for powerpc/32 powerpc/vdso32: Add crtsavres powerpc/vdso: Refactor CFLAGS for CVDSO build powerpc/vdso: Wire up getrandom() vDSO implementation on PPC32 powerpc/vdso: Wire up getrandom() vDSO implementation on PPC64
arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/asm-compat.h | 8 + arch/powerpc/include/asm/mman.h | 2 +- arch/powerpc/include/asm/vdso/getrandom.h | 54 ++++ arch/powerpc/include/asm/vdso/vsyscall.h | 6 + arch/powerpc/include/asm/vdso_datapage.h | 2 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/vdso/Makefile | 57 ++-- arch/powerpc/kernel/vdso/getrandom.S | 58 ++++ arch/powerpc/kernel/vdso/gettimeofday.S | 13 - arch/powerpc/kernel/vdso/vdso32.lds.S | 1 + arch/powerpc/kernel/vdso/vdso64.lds.S | 1 + arch/powerpc/kernel/vdso/vgetrandom-chacha.S | 299 +++++++++++++++++++ arch/powerpc/kernel/vdso/vgetrandom.c | 14 + fs/proc/task_mmu.c | 4 +- include/linux/mm.h | 4 +- include/trace/events/mmflags.h | 4 +- tools/arch/powerpc/vdso | 1 + tools/testing/selftests/vDSO/Makefile | 4 + 19 files changed, 492 insertions(+), 42 deletions(-) create mode 100644 arch/powerpc/include/asm/vdso/getrandom.h create mode 100644 arch/powerpc/kernel/vdso/getrandom.S create mode 100644 arch/powerpc/kernel/vdso/vgetrandom-chacha.S create mode 100644 arch/powerpc/kernel/vdso/vgetrandom.c create mode 120000 tools/arch/powerpc/vdso