This series wires up getrandom() vDSO implementation on powerpc.
Tested on PPC32.
Performance on powerpc 885 (using kernel selftest): ~# ./vdso_test_getrandom bench-single vdso: 2500000 times in 7.897495392 seconds libc: 2500000 times in 56.091632232 seconds syscall: 2500000 times in 55.704851989 seconds
Performance on powerpc 8321 (using kernel selftest): ~# ./vdso_test_getrandom bench-single vdso: 2500000 times in 2.017183250 seconds libc: 2500000 times in 13.088533630 seconds syscall: 2500000 times in 12.952458068 seconds
Only build tested on PPC64. There is a problem with vdso_test_getrandom selftest, it doesn't find vDSO symbol __kernel_getrandom. There is the same problem with vdso_test_gettimeofday so it is not related to getrandom.
On strange things to be clarified, there is the format of the key passed to __arch_chacha20_blocks_nostack(). In struct vgetrandom_state it is declared as a table of u32, but in reality it seems it is a flat storage that needs to be loaded in reversed byte order, so it should either be defined as a table of bytes, or as a table of __le32 but not a table of u32. But this has no impact and can be clarified later and fixed in a follow-up patch.
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 (17): asm-generic/unaligned.h: Extract common header for vDSO vdso: Clean header inclusion in getrandom vdso: Add __arch_get_k_vdso_rng_data() vdso: Add missing c-getrandom-y in Makefile vdso: Avoid call to memset() by getrandom vdso: Change getrandom's generation to unsigned long mm: Define VM_DROPPABLE for powerpc/32 powerpc: Add little endian variants of LWZX_BE and STWX_BE powerpc/vdso32: Add crtsavres powerpc/vdso: Refactor CFLAGS for CVDSO build powerpc/vdso: Wire up getrandom() vDSO implementation selftests: vdso: Fix powerpc64 vdso_config selftests: vdso: Don't hard-code location of vDSO sources selftests: vdso: Make test_vdso_getrandom look for the right vDSO function selftests: vdso: Fix build of test_vdso_chacha selftests: vdso: Make VDSO function call more generic selftests: vdso: Add support for vdso_test_random for powerpc
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 | 67 ++++ 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 | 45 ++- 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 | 297 ++++++++++++++++++ arch/powerpc/kernel/vdso/vgetrandom.c | 14 + arch/x86/entry/vdso/vma.c | 3 + arch/x86/include/asm/pvclock.h | 1 + arch/x86/include/asm/vdso/vsyscall.h | 10 +- drivers/char/random.c | 5 +- fs/proc/task_mmu.c | 4 +- include/asm-generic/unaligned.h | 11 +- include/linux/mm.h | 4 +- include/trace/events/mmflags.h | 4 +- include/vdso/datapage.h | 2 +- include/vdso/getrandom.h | 2 +- include/vdso/helpers.h | 1 + include/vdso/unaligned.h | 15 + lib/vdso/Makefile | 1 + lib/vdso/getrandom.c | 30 +- tools/arch/powerpc/vdso | 1 + tools/arch/x86/vdso | 1 + tools/include/linux/linkage.h | 4 + tools/testing/selftests/vDSO/Makefile | 12 +- tools/testing/selftests/vDSO/vdso_call.h | 52 +++ tools/testing/selftests/vDSO/vdso_config.h | 14 +- .../selftests/vDSO/vdso_test_getrandom.c | 11 +- 35 files changed, 628 insertions(+), 76 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 100644 include/vdso/unaligned.h create mode 120000 tools/arch/powerpc/vdso create mode 120000 tools/arch/x86/vdso create mode 100644 tools/testing/selftests/vDSO/vdso_call.h