Re: [PATCH v5 24/24] vDSO: Automatically enable VDSO_CHECK

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The vDSO validation tool (vdsocheck) is silently disabled for architectures that build a vDSO without generic vDSO support, such as 32-bit RISC-V and certain MIPS configurations.
--

commit e3e25811a83a299ee06c24876df0a2be2333e202
Author: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

vDSO: Automatically enable VDSO_CHECK

This patch removes the explicit selection of VDSO_CHECK from architecture
Kconfigs and attempts to enable it automatically via GENERIC_GETTIMEOFDAY and
VDSO_GETRANDOM.

> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 6cd04a9d52813..a06f243173060 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -107,7 +107,6 @@ config MIPS
>  	select TRACE_IRQFLAGS_SUPPORT
>  	select ARCH_HAS_ELFCORE_COMPAT
>  	select HAVE_ARCH_KCSAN if 64BIT
> -	select VDSO_CHECK

[Severity: Medium]
Does this removal silently disable vDSO validation for some MIPS
configurations? MIPS unconditionally selected VDSO_CHECK prior to this patch,
but now it will only get it if MIPS_GENERIC_GETTIMEOFDAY is enabled, which
depends on specific hardware clocksources like CSRC_R4K or CLKSRC_MIPS_GIC.
Without it, the build system falls back to a weaker legacy readelf script and
misses the deeper object-file validation provided by the Rust-based vdsocheck
tool.

[ ... ]

> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index e123068e15d4c..019fb47999438 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -226,7 +226,6 @@ config RISCV
>  	select THREAD_INFO_IN_TASK
>  	select TRACE_IRQFLAGS_SUPPORT
>  	select UACCESS_MEMCPY if !MMU
> -	select VDSO_CHECK if MMU
>  	select VDSO_DATASTORE if MMU
>  	select VDSO_GETRANDOM if MMU && 64BIT

[Severity: Medium]
Will 32-bit RISC-V lose VDSO validation here? 32-bit RISC-V with MMU selects
VDSO_DATASTORE, but does not select GENERIC_GETTIMEOFDAY or VDSO_GETRANDOM
(since the latter requires 64BIT). Removing VDSO_CHECK here leaves 32-bit
architectures without the deeper object-file validation provided by
vdsocheck.

[ ... ]

> diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
> index 112b42a5aeb1a..12a640c78b72f 100644
> --- a/lib/vdso/Kconfig
> +++ b/lib/vdso/Kconfig
> @@ -6,6 +6,7 @@ config VDSO_DATASTORE
>  config GENERIC_GETTIMEOFDAY
>  	bool
>  	select VDSO_DATASTORE
> +	select VDSO_CHECK
>  	help

[Severity: Medium]
Is it intentional to tie a generic validation tool like VDSO_CHECK strictly
to specific vDSO features like GENERIC_GETTIMEOFDAY and VDSO_GETRANDOM? As
noted above, this seems to miss architectures that build a vDSO without
generic vDSO support but still rely on vdsocheck.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260908-vdso-absolute-reloc-v5-0-3a93791af1cf@linutronix.de?part=24