[PATCH 6/7] bug: Consolidate __WARN_FLAGS usage

From: Kees Cook
Date: Mon Aug 19 2019 - 19:41:29 EST


Instead of having separate tests for __WARN_FLAGS, merge the two #ifdef
blocks and replace the synonym WANT_WARN_ON_SLOWPATH macro.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/asm-generic/bug.h | 18 +++++++-----------
kernel/panic.c | 2 +-
2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 6ea8d258cb96..588dd59a5b72 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -61,16 +61,6 @@ struct bug_entry {
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
#endif

-#ifdef __WARN_FLAGS
-#define WARN_ON_ONCE(condition) ({ \
- int __ret_warn_on = !!(condition); \
- if (unlikely(__ret_warn_on)) \
- __WARN_FLAGS(BUGFLAG_ONCE | \
- BUGFLAG_TAINT(TAINT_WARN)); \
- unlikely(__ret_warn_on); \
-})
-#endif
-
/*
* WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
* significant kernel issues that need prompt attention if they should ever
@@ -91,7 +81,6 @@ struct bug_entry {
extern __printf(4, 5)
void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
const char *fmt, ...);
-#define WANT_WARN_ON_SLOWPATH
#define __WARN() __WARN_printf(TAINT_WARN, NULL)
#define __WARN_printf(taint, arg...) \
warn_slowpath_fmt(__FILE__, __LINE__, taint, arg)
@@ -105,6 +94,13 @@ extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
__warn_printk(arg); \
__WARN_FLAGS(BUGFLAG_TAINT(taint)); \
} while (0)
+#define WARN_ON_ONCE(condition) ({ \
+ int __ret_warn_on = !!(condition); \
+ if (unlikely(__ret_warn_on)) \
+ __WARN_FLAGS(BUGFLAG_ONCE | \
+ BUGFLAG_TAINT(TAINT_WARN)); \
+ unlikely(__ret_warn_on); \
+})
#endif

/* used internally by panic.c */
diff --git a/kernel/panic.c b/kernel/panic.c
index dc2243429903..233219b3fb34 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -588,7 +588,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
add_taint(taint, LOCKDEP_STILL_OK);
}

-#ifdef WANT_WARN_ON_SLOWPATH
+#ifndef __WARN_FLAGS
void warn_slowpath_fmt(const char *file, int line, unsigned taint,
const char *fmt, ...)
{
--
2.17.1