The following commit has been merged into the objtool/core branch of tip: Commit-ID: c721b3f80faebc7891211fa82de303eebadfed15 Gitweb: https://git.kernel.org/tip/c721b3f80faebc7891211fa82de303eebadfed15 Author: Alexandre Chartre <alexandre.char...@oracle.com> AuthorDate: Tue, 07 Apr 2020 09:31:35 +02:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Thu, 30 Apr 2020 20:14:32 +02:00
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 <alexandre.char...@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Reviewed-by: Miroslav Benes <mbe...@suse.cz> Acked-by: Josh Poimboeuf <jpoim...@redhat.com> Link: https://lkml.kernel.org/r/20200407073142.20659-3-alexandre.char...@oracle.com --- tools/objtool/check.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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)
