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authorVincenzo Frascino <vincenzo.frascino@arm.com>2020-04-29 16:10:50 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2020-04-30 18:35:32 +0100
commit1578e5d03112e3e9d37e1c4d95b6dfb734c73955 (patch)
tree3c56c3777bd97e3619d23a6374081d4d6c52227b
parent6a8b55ed4056ea5559ebe4f6a4b247f627870d4c (diff)
arm64: vdso: Add -fasynchronous-unwind-tables to cflags
On arm64 linux gcc uses -fasynchronous-unwind-tables -funwind-tables by default since gcc-8, so now the de facto platform ABI is to allow unwinding from async signal handlers. However on bare metal targets (aarch64-none-elf), and on old gcc, async and sync unwind tables are not enabled by default to avoid runtime memory costs. This means if linux is built with a baremetal toolchain the vdso.so may not have unwind tables which breaks the gcc platform ABI guarantee in userspace. Add -fasynchronous-unwind-tables explicitly to the vgettimeofday.o cflags to address the ABI change. Fixes: 28b1a824a4f4 ("arm64: vdso: Substitute gettimeofday() with C implementation") Cc: Will Deacon <will@kernel.org> Reported-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/kernel/vdso/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index dd2514bb1511..3862cad2410c 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -32,7 +32,7 @@ UBSAN_SANITIZE := n
OBJECT_FILES_NON_STANDARD := y
KCOV_INSTRUMENT := n
-CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny
+CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)