For the rationale to implement getrandom() in vDSO see [1].
The vDSO getrandom() needs a stack-less ChaCha20 implementation, so we
need to add architecture-specific code and wire it up with the generic
code.
The implementation is tested with the kernel vDSO selftests, which need
to be adapted as well. The selftest changes are also included in the
series.
The vdso_test_getrandom bench-single result:
vdso: 25000000 times in 0.501461533 seconds
libc: 25000000 times in 6.975149458 seconds
syscall: 25000000 times in 6.985865529 seconds
The vdso_test_getrandom bench-multi result:
vdso: 25000000 x 256 times in 28.688809414 seconds
libc: 25000000 x 256 times in 356.863400242 seconds
syscall: 25000000 x 256 times in 338.562183570 seconds
[1]:https://lore.kernel.org/all/20240712014009.281406-1-Jason@xxxxxxxxx/
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: loongarch@xxxxxxxxxxxxxxx
Cc: Jinyang He <hejinyang@xxxxxxxxxxx>
Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
[v3]->v4:
- Remove LSX implementation, which isn't much faster than the generic
implementaion.
- Rebase onto crng/random.git:
- Define __arch_get_k_vdso_rng_data instead of using inline asm to
provide the _vdso_rng_data symbol in a magic way.
- Remove memset.S.
- Use c-getrandom-y to easily include the generic C code.
- The benchmark results seem better than v3, maybe related to the TLS
refactoring in random.git.
- Add patches for selftests.
[v2]->v3:
- Add a generic LoongArch implementation for which LSX isn't needed.
v1->v2:
- Properly send the series to the list.
[v3]:https://lore.kernel.org/all/20240816110717.10249-1-xry111@xxxxxxxxxxx/
[v2]:https://lore.kernel.org/all/20240815133357.35829-1-xry111@xxxxxxxxxxx/
Xi Ruoyao (4):
LoongArch: vDSO: Wire up getrandom() vDSO implementation
selftests/vDSO: Add --cflags for pkg-config command querying libsodium
selftests/vDSO: Use KHDR_INCLUDES to locate UAPI headers for
vdso_test_getrandom
selftests/vDSO: Enable vdso getrandom tests for LoongArch
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/vdso/getrandom.h | 47 ++++
arch/loongarch/include/asm/vdso/vdso.h | 8 +
arch/loongarch/include/asm/vdso/vsyscall.h | 10 +
arch/loongarch/kernel/asm-offsets.c | 10 +
arch/loongarch/kernel/vdso.c | 2 +
arch/loongarch/vdso/Makefile | 6 +
arch/loongarch/vdso/vdso.lds.S | 1 +
arch/loongarch/vdso/vgetrandom-chacha.S | 239 ++++++++++++++++++++
arch/loongarch/vdso/vgetrandom.c | 12 +
tools/arch/loongarch/vdso | 1 +
tools/testing/selftests/vDSO/Makefile | 8 +-
12 files changed, 341 insertions(+), 4 deletions(-)
create mode 100644 arch/loongarch/include/asm/vdso/getrandom.h
create mode 100644 arch/loongarch/vdso/vgetrandom-chacha.S
create mode 100644 arch/loongarch/vdso/vgetrandom.c
create mode 120000 tools/arch/loongarch/vdso
base-commit: c64dcc01ebf2b7d5a7cb56b5c6a4b6adc2273774
--
2.46.0
