linux/arch/arm64/kernel/vdso32
Will Deacon a4eb355a3f arm64: vdso: Fix CFI directives in sigreturn trampoline
Daniel reports that the .cfi_startproc is misplaced for the sigreturn
trampoline, which causes LLVM's unwinder to misbehave:

  | I run into this with LLVM’s unwinder.
  | This combination was always broken.

This prompted Dave to question our use of CFI directives more generally,
and I ended up going down a rabbit hole trying to figure out how this
very poorly documented stuff gets used.

Move the CFI directives so that the "mysterious NOP" is included in
the .cfi_{start,end}proc block and add a bunch of comments so that I
can save myself another headache in future.

Cc: Tamas Zsoldos <tamas.zsoldos@arm.com>
Reported-by: Dave Martin <dave.martin@arm.com>
Reported-by: Daniel Kiss <daniel.kiss@arm.com>
Tested-by: Daniel Kiss <daniel.kiss@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-21 12:59:26 +01:00
..
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Makefile arm64: vdso32: Enable Clang Compilation 2020-03-21 15:24:03 +01:00
note.c
sigreturn.S arm64: vdso: Fix CFI directives in sigreturn trampoline 2020-05-21 12:59:26 +01:00
vdso.lds.S
vdso.S
vgettimeofday.c arm64: vdso32: Include common headers in the vdso library 2020-03-21 15:24:02 +01:00