linux-kernel - [PATCH 04/11] Revert "objtool: Increase per-function WARN

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e5abe5e858acf1a9207a5dfa0f37d17ac9dca872.1743481539.git.jpoimboe@kernel.org>
Date: Mon, 31 Mar 2025 21:26:39 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH 04/11] Revert "objtool: Increase per-function WARN_FUNC() rate limit"

This reverts commit 0a7fb6f07e3ad497d31ae9a2082d2cacab43d54a.

The "skipping duplicate warnings" warning is technically not an actual
warning, which can cause confusion.  This feature isn't all that useful
anyway.  It's exceedingly rare for a function to have more than one
unrelated warning.

Suggested-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 tools/objtool/check.c                |  4 ++--
 tools/objtool/include/objtool/elf.h  |  2 +-
 tools/objtool/include/objtool/warn.h | 14 +++-----------
 3 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index bd0c78bfe90c..c8b3c8e7090c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3545,7 +3545,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 			WARN("%s() falls through to next function %s()",
 			     func->name, insn_func(insn)->name);
-			func->warnings++;
+			func->warned = 1;
 
 			return 1;
 		}
@@ -4576,7 +4576,7 @@ static void disas_warned_funcs(struct objtool_file *file)
 	char *funcs = NULL, *tmp;
 
 	for_each_sym(file, sym) {
-		if (sym->warnings) {
+		if (sym->warned) {
 			if (!funcs) {
 				funcs = malloc(strlen(sym->name) + 1);
 				if (!funcs) {
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index eba04392c6fd..c7c4e87ebe88 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -65,11 +65,11 @@ struct symbol {
 	u8 return_thunk      : 1;
 	u8 fentry            : 1;
 	u8 profiling_func    : 1;
+	u8 warned	     : 1;
 	u8 embedded_insn     : 1;
 	u8 local_label       : 1;
 	u8 frame_pointer     : 1;
 	u8 ignore	     : 1;
-	u8 warnings	     : 2;
 	struct list_head pv_target;
 	struct reloc *relocs;
 };
diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h
index b29ac144e4f5..e3ad9b2caf87 100644
--- a/tools/objtool/include/objtool/warn.h
+++ b/tools/objtool/include/objtool/warn.h
@@ -57,22 +57,14 @@ static inline char *offstr(struct section *sec, unsigned long offset)
 	free(_str);					\
 })
 
-#define WARN_LIMIT 2
-
 #define WARN_INSN(insn, format, ...)					\
 ({									\
 	struct instruction *_insn = (insn);				\
-	BUILD_BUG_ON(WARN_LIMIT > 2);					\
-	if (!_insn->sym || _insn->sym->warnings < WARN_LIMIT) {		\
+	if (!_insn->sym || !_insn->sym->warned)				\
 		WARN_FUNC(format, _insn->sec, _insn->offset,		\
 			  ##__VA_ARGS__);				\
-		if (_insn->sym)						\
-			_insn->sym->warnings++;				\
-	} else if (_insn->sym && _insn->sym->warnings == WARN_LIMIT) {	\
-		WARN_FUNC("skipping duplicate warning(s)",		\
-			  _insn->sec, _insn->offset);			\
-		_insn->sym->warnings++;					\
-	}								\
+	if (_insn->sym)							\
+		_insn->sym->warned = 1;					\
 })
 
 #define BT_INSN(insn, format, ...)				\
-- 
2.48.1