[PATCH 5/5] objtool: Make BP scratch register warning more robust

From: Josh Poimboeuf
Date: Wed Apr 01 2020 - 14:23:50 EST


If func is NULL, a seg fault can result.

This is a theoretical issue which was found by Coverity.

Fixes: c705cecc8431 ("objtool: Track original function across branches")
Addresses-Coverity-ID: 1492002 ("Dereference after null check")
Reported-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/check.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index c681a26c25ac..93fa7be67e9f 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2023,8 +2023,8 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct
}

if (state->bp_scratch) {
- WARN("%s uses BP as a scratch register",
- func->name);
+ WARN_FUNC("BP used as a scratch register",
+ insn->sec, insn->offset);
return 1;
}

--
2.21.1