TencentOS-kernel/arch/arm64/kernel/vdso
Vincenzo Frascino ee2a797c3f arm64: vdso: Add -fasynchronous-unwind-tables to cflags
commit 1578e5d03112e3e9d37e1c4d95b6dfb734c73955 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:27:24 +08:00
..
.gitignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile arm64: vdso: Add -fasynchronous-unwind-tables to cflags 2021-03-16 16:27:24 +08:00
gen_vdso_offsets.sh Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
note.S Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sigreturn.S Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
vdso.S Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
vdso.lds.S Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
vgettimeofday.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00