diff options
| author | Alexandre Chartre <[email protected]> | 2020-04-07 09:31:35 +0200 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2020-04-30 20:14:32 +0200 |
| commit | c721b3f80faebc7891211fa82de303eebadfed15 (patch) | |
| tree | 0f1258e019372fb4577b689010ed19592e1b3892 | |
| parent | 87cf61fe848ca8ddf091548671e168f52e8a718e (diff) | |
objtool: UNWIND_HINT_RET_OFFSET should not check registers
UNWIND_HINT_RET_OFFSET will adjust a modified stack. However if a
callee-saved register was pushed on the stack then the stack frame
will still appear modified. So stop checking registers when
UNWIND_HINT_RET_OFFSET is used.
Signed-off-by: Alexandre Chartre <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
| -rw-r--r-- | tools/objtool/check.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8af8de2299e8..068897d5d956 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1507,6 +1507,14 @@ static bool has_modified_stack_frame(struct instruction *insn, struct insn_state if (cfi->stack_size != initial_func_cfi.cfa.offset + ret_offset) return true; + /* + * If there is a ret offset hint then don't check registers + * because a callee-saved register might have been pushed on + * the stack. + */ + if (ret_offset) + return false; + for (i = 0; i < CFI_NUM_REGS; i++) { if (cfi->regs[i].base != initial_func_cfi.regs[i].base || cfi->regs[i].offset != initial_func_cfi.regs[i].offset) |