On 04.06.2020 17:14, Jann Horn wrote: > On Thu, Jun 4, 2020 at 3:58 PM Will Deacon <w...@kernel.org> wrote: >> On Thu, Jun 04, 2020 at 04:49:57PM +0300, Alexander Popov wrote: >>> Don't try instrumenting functions in arch/arm64/kernel/vdso/vgettimeofday.c. >>> Otherwise that can cause issues if the cleanup pass of stackleak gcc plugin >>> is disabled. >>> >>> Signed-off-by: Alexander Popov <alex.po...@linux.com> >>> --- >>> arch/arm64/kernel/vdso/Makefile | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/arm64/kernel/vdso/Makefile >>> b/arch/arm64/kernel/vdso/Makefile >>> index 3862cad2410c..9b84cafbd2da 100644 >>> --- a/arch/arm64/kernel/vdso/Makefile >>> +++ b/arch/arm64/kernel/vdso/Makefile >>> @@ -32,7 +32,8 @@ UBSAN_SANITIZE := n >>> OBJECT_FILES_NON_STANDARD := y >>> KCOV_INSTRUMENT := n >>> >>> -CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables >>> +CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables \ >>> + $(DISABLE_STACKLEAK_PLUGIN) >> >> I can pick this one up via arm64, thanks. Are there any other plugins we >> should be wary of?
I can't tell exactly. I'm sure Kees has the whole picture. >> It looks like x86 filters out $(GCC_PLUGINS_CFLAGS) >> when building the vDSO. Yes, that's why building x86 vDSO doesn't need $(DISABLE_STACKLEAK_PLUGIN). > Maybe at some point we should replace exclusions based on > GCC_PLUGINS_CFLAGS and KASAN_SANITIZE and UBSAN_SANITIZE and > OBJECT_FILES_NON_STANDARD and so on with something more generic... > something that says "this file will not be built into the normal > kernel, it contains code that runs in realmode / userspace / some > similarly weird context, and none of our instrumentation > infrastructure is available there"... Good idea. I would also add 'notrace' to that list. Best regards, Alexander
