The macro trace_printk() uses a hardcoded identifier _______STR
within a statement expression, which can lead to variable name
shadowing if a caller happens to use the same name in its scope.
Following the pattern in commit 24ba53017e18 ("rcu: Replace ________p1
and _________p1 with __UNIQUE_ID(rcu)") and commit 589a9785ee3a
("min/max: remove sparse warnings when they're nested"), replace the
hardcoded identifier with __UNIQUE_ID(STR).
Since __UNIQUE_ID() must be expanded once to remain consistent across
declaration and sizeof() within the statement expression, introduce a
nested helper macro ___trace_printk.
Signed-off-by: Qian-Yu Lin <[email protected]>
---
include/linux/trace_printk.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/linux/trace_printk.h b/include/linux/trace_printk.h
index 2670ec7f4262..060eccb40838 100644
--- a/include/linux/trace_printk.h
+++ b/include/linux/trace_printk.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_TRACE_PRINTK_H
#define _LINUX_TRACE_PRINTK_H
+#include <linux/compiler.h>
#include <linux/compiler_attributes.h>
#include <linux/instruction_pointer.h>
#include <linux/stddef.h>
@@ -84,15 +85,18 @@ do {
\
* let gcc optimize the rest.
*/
-#define trace_printk(fmt, ...) \
+#define ___trace_printk(fmt, str, ...) \
do { \
- char _______STR[] = __stringify((__VA_ARGS__)); \
- if (sizeof(_______STR) > 3) \
+ char str[] = __stringify((__VA_ARGS__)); \
+ if (sizeof(str) > 3) \
do_trace_printk(fmt, ##__VA_ARGS__); \
else \
trace_puts(fmt); \
} while (0)
+#define trace_printk(fmt, ...) \
+ ___trace_printk(fmt, __UNIQUE_ID(str), ##__VA_ARGS__)
+
#define do_trace_printk(fmt, args...) \
do { \
static const char *trace_printk_fmt __used \
--
2.25.1
