From: Alexandre Chartre Date: Tue, 7 Apr 2020 07:31:35 +0000 (+0200) Subject: objtool: UNWIND_HINT_RET_OFFSET should not check registers X-Git-Tag: v5.10.7~2529^2~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c721b3f80faebc7891211fa82de303eebadfed15;p=platform%2Fkernel%2Flinux-rpi.git 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 Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Miroslav Benes Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20200407073142.20659-3-alexandre.chartre@oracle.com --- diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8af8de2..068897d 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)