release/5.2.37/bug-consolidate-warn_slowpath_fmt-usage.patch

From 91aec3cc3c10ba223921c21e547728ddd8f222f7 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Wed, 25 Sep 2019 16:47:58 -0700
Subject: [PATCH] bug: consolidate warn_slowpath_fmt() usage

commit f2f84b05e02b7710a201f0017b3272ad7ef703d1 upstream.

Instead of having a separate helper for no printk output, just consolidate
the logic into warn_slowpath_fmt().

Link: http://lkml.kernel.org/r/20190819234111.9019-4-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 2d35bbf687d0..598d7072602f 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -93,9 +93,8 @@ struct bug_entry {
 extern __printf(4, 5)
 void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
 		       const char *fmt, ...);
-extern void warn_slowpath_null(const char *file, const int line);
 #define WANT_WARN_ON_SLOWPATH
-#define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
+#define __WARN()		__WARN_printf(TAINT_WARN, NULL)
 #define __WARN_printf(taint, arg...)					\
 	warn_slowpath_fmt(__FILE__, __LINE__, taint, arg)
 #else
diff --git a/kernel/panic.c b/kernel/panic.c
index d26e2170331f..7907e8a99e32 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -598,19 +598,19 @@ void warn_slowpath_fmt(const char *file, int line, unsigned taint,
 {
 	struct warn_args args;
 
+	if (!fmt) {
+		pr_warn(CUT_HERE);
+		__warn(file, line, __builtin_return_address(0), taint,
+		       NULL, NULL);
+		return;
+	}
+
 	args.fmt = fmt;
 	va_start(args.args, fmt);
 	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
-
-void warn_slowpath_null(const char *file, int line)
-{
-	pr_warn(CUT_HERE);
-	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
-}
-EXPORT_SYMBOL(warn_slowpath_null);
 #else
 void __warn_printk(const char *fmt, ...)
 {
-- 
2.7.4