linux/arch
Will Deacon 49a3b0e1c0 arm64: vdso: Only pass --no-eh-frame-hdr when linker supports it
Commit 87676cfca1 ("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: 87676cfca1 ("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>
2020-06-24 13:23:10 +01:00
..
alpha Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
arc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
arm Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
arm64 arm64: vdso: Only pass --no-eh-frame-hdr when linker supports it 2020-06-24 13:23:10 +01:00
c6x This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
csky mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
h8300 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
hexagon treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ia64 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
m68k Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
microblaze mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mips Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
nds32 mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
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powerpc Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
riscv RISC-V Patches for the 5.8 Merge Window, Part 2 2020-06-11 12:55:20 -07:00
s390 Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
sh treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
sparc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
um treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
unicore32 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
x86 Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
xtensa mmap locking API: convert mmap_sem API comments 2020-06-09 09:39:14 -07:00
.gitignore
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00