[tip:core/urgent] objtool: Warn on zero-length functions

[tip-bot for Josh Poimboeuf]

Commit-ID:  61e9b75a0ccf1fecacc28a2d77ea4a19aa404e39
Gitweb:     https://git.kernel.org/tip/61e9b75a0ccf1fecacc28a2d77ea4a19aa404e39
Author:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 17 Jul 2019 20:36:49 -0500
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 18 Jul 2019 21:01:07 +0200

objtool: Warn on zero-length functions

All callable functions should have an ELF size.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/03d429c4fa87829c61c5dc0e89652f4d9efb62f1.1563413318.git.jpoimboe@xxxxxxxxxx

---
 tools/objtool/check.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3f8664b0e3f9..dece3253ff6a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2357,6 +2357,12 @@ static int validate_functions(struct objtool_file *file)
 			if (func->type != STT_FUNC)
 				continue;
 
+			if (!func->len) {
+				WARN("%s() is missing an ELF size annotation",
+				     func->name);
+				warnings++;
+			}
+
 			if (func->pfunc != func || func->alias != func)
 				continue;