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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-22 00:29:24 +0300 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-01-26 20:12:00 +0300 |
| commit | b735bd3e68824316655252a931a3353a6ebc036f (patch) | |
| tree | 24a879a66b4ce0549a05d2aca3ec81dab212b128 /arch/x86/include/asm/unwind_hints.h | |
| parent | 081df94301e317e84c3413686043987da2c3e39d (diff) | |
| download | linux-b735bd3e68824316655252a931a3353a6ebc036f.tar.xz | |
objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC
The ORC metadata generated for UNWIND_HINT_FUNC isn't actually very
func-like. With certain usages it can cause stack state mismatches
because it doesn't set the return address (CFI_RA).
Also, users of UNWIND_HINT_RET_OFFSET no longer need to set a custom
return stack offset. Instead they just need to specify a func-like
situation, so the current ret_offset code is hacky for no good reason.
Solve both problems by simplifying the RET_OFFSET handling and
converting it into a more useful UNWIND_HINT_FUNC.
If we end up needing the old 'ret_offset' functionality again in the
future, we should be able to support it pretty easily with the addition
of a custom 'sp_offset' in UNWIND_HINT_FUNC.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/db9d1f5d79dddfbb3725ef6d8ec3477ad199948d.1611263462.git.jpoimboe@redhat.com
Diffstat (limited to 'arch/x86/include/asm/unwind_hints.h')
| -rw-r--r-- | arch/x86/include/asm/unwind_hints.h | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 664d4610d700..8e574c0afef8 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -48,17 +48,8 @@ UNWIND_HINT_REGS base=\base offset=\offset partial=1 .endm -.macro UNWIND_HINT_FUNC sp_offset=8 - UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=\sp_offset type=UNWIND_HINT_TYPE_CALL -.endm - -/* - * RET_OFFSET: Used on instructions that terminate a function; mostly RETURN - * and sibling calls. On these, sp_offset denotes the expected offset from - * initial_func_cfi. - */ -.macro UNWIND_HINT_RET_OFFSET sp_offset=8 - UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset +.macro UNWIND_HINT_FUNC + UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC .endm #endif /* __ASSEMBLY__ */ |