Re: [PATCH v5 17/24] powerpc/vdso: Enable the vdsocheck tool

[Christophe Leroy (CS GROUP)]

Le 08/09/2026 à 08:33, Thomas Weißschuh a écrit :
> The vdsocheck tool validates the object files and final .so library.
> It can detect if the compiler created relocations which are incompatible
> with the vDSO which need to be worked around.
>
> Wire it up for the architecture.
>
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
> ---
>   arch/powerpc/Kconfig              |  1 +
>   arch/powerpc/kernel/vdso/Makefile |  4 ++--
>   lib/vdso/check/vdsocheck.rs       | 27 +++++++++++++++++++++++++++
>   3 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 2580e27e4328..f19e225cfc5c 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -330,6 +330,7 @@ config PPC
>   	select SYSCTL_EXCEPTION_TRACE
>   	select THREAD_INFO_IN_TASK
>   	select TRACE_IRQFLAGS_SUPPORT
> +	select VDSO_CHECK
>   	select VDSO_DATASTORE
>   	select VDSO_GETRANDOM
>   	#
> diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
> index 368759f81708..ca20b91b4373 100644
> --- a/arch/powerpc/kernel/vdso/Makefile
> +++ b/arch/powerpc/kernel/vdso/Makefile
> @@ -81,9 +81,9 @@ targets += vdso64.lds
>   CPPFLAGS_vdso64.lds += -P -C
>   
>   # link rule for the .so file, .lds has to be first
> -$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o FORCE
> +$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o $(vdsocheck) FORCE
>   	$(call if_changed,vdso32ld_and_check)
> -$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o FORCE
> +$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o $(vdsocheck) FORCE
>   	$(call if_changed,vdso64ld_and_check)
>   
>   # assembly rules for the .S files
> diff --git a/lib/vdso/check/vdsocheck.rs b/lib/vdso/check/vdsocheck.rs
> index e45a1fbc6829..429bdcd65818 100644
> --- a/lib/vdso/check/vdsocheck.rs
> +++ b/lib/vdso/check/vdsocheck.rs
> @@ -69,6 +69,33 @@ fn allowed_relocations_for_machine(machine: u16) -> Option<AllowedRelocations<'s
>               ..Default::default()
>           }
>           .into(),
> +        bindings::EM_PPC => AllowedRelocations {
> +            in_object_file: &[
> +                bindings::R_PPC_REL24,

Not sure this is correct, see commit 42ed6d56ade2 ("powerpc/vdso: Block 
R_PPC_REL24 relocations")

> +                bindings::R_PPC_REL14,
> +                bindings::R_PPC_REL32,
> +                bindings::R_PPC_REL16,
> +                bindings::R_PPC_REL16_LO,
> +                bindings::R_PPC_REL16_HI,
> +                bindings::R_PPC_REL16_HA,
> +            ],
> +            ..Default::default()
> +        }
> +        .into(),
> +        bindings::EM_PPC64 => AllowedRelocations {
> +            in_object_file: &[
> +                bindings::R_PPC64_REL24,

Not sure this is correct, see commit 42ed6d56ade2 ("powerpc/vdso: Block 
R_PPC_REL24 relocations")

> +                bindings::R_PPC64_REL14,
> +                bindings::R_PPC64_REL32,
> +                bindings::R_PPC64_REL64,
> +                bindings::R_PPC64_REL16,
> +                bindings::R_PPC64_REL16_LO,
> +                bindings::R_PPC64_REL16_HI,
> +                bindings::R_PPC64_REL16_HA,
> +            ],
> +            ..Default::default()
> +        }
> +        .into(),
>           _ => None,
>       }
>   }