Re: [PATCH 04/13] powerpc: Disable CONFIG_DCACHE_WORD_ACCESS when KMSAN is enabled
From: Christophe Leroy <hidden>
Date: 2023-12-14 08:42:16
Also in:
linux-mm, lkml
Le 14/12/2023 à 06:55, Nicholas Miehlbradt a écrit :
quoted hunk ↗ jump to hunk
Word sized accesses may read uninitialized data when optimizing loads. Disable this optimization when KMSAN is enabled to prevent false positives. Signed-off-by: Nicholas Miehlbradt <redacted> --- arch/powerpc/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 6f105ee4f3cf..e33e3250c478 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig@@ -182,7 +182,7 @@ config PPC select BUILDTIME_TABLE_SORT select CLONE_BACKWARDS select CPUMASK_OFFSTACK if NR_CPUS >= 8192 - select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN + select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN && !KMSAN select DMA_OPS_BYPASS if PPC64 select DMA_OPS if PPC64 select DYNAMIC_FTRACE if FUNCTION_TRACER
Seems like all archs do this. Maybe a better approach would be to define a HAVE_DCACHE_WORD_ACCESS that is selected by arches, and then the core part select DCACHE_WORD_ACCESS when HAVE_DCACHE_WORD_ACCESS && !KMSAN Christophe