Custom toolchains that modify the default target to -mthumb cannot compile the arm64 compat vdso32, as arch/arm64/include/asm/vdso/compat_gettimeofday.h contains assembly that's invalid in -mthumb. Force the use of -marm, always.
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084372 Cc: Stephen Boyd <swb...@google.com> Reported-by: Luis Lozano <lloz...@google.com> Tested-by: Manoj Gupta <manojgu...@google.com> Signed-off-by: Nick Desaulniers <ndesaulni...@google.com> --- Surgeon General's Warning: changing the compiler defaults is not recommended and can lead to spooky bugs that are hard to reproduce upstream. arch/arm64/kernel/vdso32/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 3964738ebbde..c449a293d81e 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -104,6 +104,8 @@ VDSO_CFLAGS += -D__uint128_t='void*' # (on GCC 4.8 or older, there is unfortunately no way to silence this warning) VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow) VDSO_CFLAGS += -Wno-int-to-pointer-cast +# Force vdso to be compiled in ARM mode, not THUMB. +VDSO_CFLAGS += -marm VDSO_AFLAGS := $(VDSO_CAFLAGS) VDSO_AFLAGS += -D__ASSEMBLY__ -- 2.27.0.rc0.183.gde8f92d652-goog
