Re: [PATCH v6 0/3] LoongArch: Implement getrandom() in vDSO

[Huacai Chen]

For the whole series,
Acked-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>

On Sun, Sep 1, 2024 at 2:13 PM Xi Ruoyao <xry111@xxxxxxxxxxx> wrote:
>
> Implement stack-less ChaCha20 and wire it with the generic vDSO
> getrandom code.  It passes vdso_test_chacha test, and the
> vdso_test_getrandom results:
>
> bench-single:
>
>    vdso: 25000000 times in 0.527882568 seconds
>    libc: 25000000 times in 6.963153452 seconds
> syscall: 25000000 times in 6.980286094 seconds
>
> bench-multi:
>
>    vdso: 25000000 x 256 times in 29.405172862 seconds
>    libc: 25000000 x 256 times in 355.692605551 seconds
>    syscall: 25000000 x 256 times in 338.481559154 seconds
>
> bench-single in an unshared time namespace:
>
>    vdso: 25000000 times in 0.528282411 seconds
>    libc: 25000000 times in 6.966410240 seconds
> syscall: 25000000 times in 6.976614579 seconds
>
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: loongarch@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: Jinyang He <hejinyang@xxxxxxxxxxx>
> Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> Cc:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
>
> [v5]->v6:
> - Rebase onto crng/random.git.
> - Separate selftest patch from the implementation patch again (both I
>   and Huacai perfer this way).
> - Add a patch to provide a __vdso_getrandom prototype shared by all
>   ports, similar to the __vdso_gettimeofday prototype added by Arnd in
>   commit 42874e4eb35b ("arch: vdso: consolidate gettime prototypes").
> - Stop breaking lines at 80 characters for C code.
> - In vdso.lds.S and Makefile, keep sigreturn the last in the lists.
>
> [v4]->v5:
> - Rebase onto crng/random.git:
>   - Remove two selftest patches.
>   - Remove __arch_chacha20_blocks_nostack forward declaration.
> - Squash the remaining selftest patch into the vDSO getrandom
>   implementation patch.
> - Remove ifdef CONFIG_VDSO_GETRANDOM and $(CONFIG_VDSO_GETRANDOM) as
>   they are always true in arch/loongarch.
> - Remove asm-offsets.c change which has been already unneeded in v4.
> - Add comment about rematerializing the constant in the assembly code.
> - Add prototype for __vdso_getrandom to silence a -Wmissing-prototype
>   warning.
>
> [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.
>
> [v5]:https://lore.kernel.org/all/20240829125656.19017-1-xry111@xxxxxxxxxxx/
> [v4]:https://lore.kernel.org/all/20240827132018.88854-1-xry111@xxxxxxxxxxx/
> [v3]:https://lore.kernel.org/all/20240816110717.10249-1-xry111@xxxxxxxxxxx/
> [v2]:https://lore.kernel.org/all/20240815133357.35829-1-xry111@xxxxxxxxxxx/
>
> Xi Ruoyao (3):
>   arch: vDSO: Add a __vdso_getrandom prototype for all architectures
>   LoongArch: vDSO: Wire up getrandom() vDSO implementation
>   selftests/vDSO: Enable vdso getrandom tests for LoongArch
>
>  arch/loongarch/Kconfig                      |   1 +
>  arch/loongarch/include/asm/vdso/getrandom.h |  38 +++
>  arch/loongarch/include/asm/vdso/vdso.h      |   6 +
>  arch/loongarch/include/asm/vdso/vsyscall.h  |   8 +
>  arch/loongarch/kernel/vdso.c                |   1 +
>  arch/loongarch/vdso/Makefile                |   7 +-
>  arch/loongarch/vdso/vdso.lds.S              |   1 +
>  arch/loongarch/vdso/vgetrandom-chacha.S     | 242 ++++++++++++++++++++
>  arch/loongarch/vdso/vgetrandom.c            |  10 +
>  arch/x86/entry/vdso/vgetrandom.c            |   2 -
>  include/vdso/getrandom.h                    |   5 +
>  tools/arch/loongarch/vdso                   |   1 +
>  tools/testing/selftests/vDSO/Makefile       |   4 +-
>  13 files changed, 321 insertions(+), 5 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: 0dfed8092247b5e179f52d27b93533bce3eaf5ba
> --
> 2.46.0
>
>