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authorWill Deacon <will@kernel.org>2020-06-24 13:23:10 +0100
committerWill Deacon <will@kernel.org>2020-06-24 13:23:10 +0100
commit49a3b0e1c05ab3601100a723f7ea207dc99a492a (patch)
tree546fe76c8ea716afac3c80ed8296d388269ce8c1
parent4dc9b282bf5fc80b1761bac467adf78cd417b777 (diff)
arm64: vdso: Only pass --no-eh-frame-hdr when linker supports it
Commit 87676cfca141 ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline") unconditionally passes the '--no-eh-frame-hdr' option to the linker when building the native vDSO in an attempt to prevent generation of the .eh_frame_hdr section, the presence of which has been implicated in segfaults originating from the libgcc unwinder. Unfortunately, not all versions of binutils support this option, which has been shown to cause build failures in linux-next: | CALL scripts/atomic/check-atomics.sh | CALL scripts/checksyscalls.sh | LD arch/arm64/kernel/vdso/vdso.so.dbg | ld: unrecognized option '--no-eh-frame-hdr' | ld: use the --help option for usage information | arch/arm64/kernel/vdso/Makefile:64: recipe for target | 'arch/arm64/kernel/vdso/vdso.so.dbg' failed | make[1]: *** [arch/arm64/kernel/vdso/vdso.so.dbg] Error 1 | arch/arm64/Makefile:175: recipe for target 'vdso_prepare' failed | make: *** [vdso_prepare] Error 2 Only link the vDSO with '--no-eh-frame-hdr' when the linker supports it. If we end up with the section due to linker defaults, the absence of CFI information in the sigreturn trampoline will prevent the unwinder from breaking. Link: https://lore.kernel.org/r/7a7e31a8-9a7b-2428-ad83-2264f20bdc2d@hisilicon.com Fixes: 87676cfca141 ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline") Reported-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--arch/arm64/kernel/vdso/Makefile5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 1e5a940532da..97d3d3632093 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -23,8 +23,9 @@ btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti
# potential future proofing if we end up with internal calls to the exported
# routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
# preparation in build-time C")).
-ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
- -Bsymbolic --no-eh-frame-hdr --build-id -n $(btildflags-y) -T
+ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
+ -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id -n \
+ $(btildflags-y) -T
ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
ccflags-y += -DDISABLE_BRANCH_PROFILING