[PATCH v2 1/1] printk: add __printf attributes to internal functions

From: Nicolas Iooss
Date: Wed May 24 2017 - 01:57:23 EST


When compiling with -Wsuggest-attribute=format, gcc complains that some
functions in kernel/printk/printk_safe.c transmit their argument to
printf-like functions without having a printf attribute. Silence these
warnings by adding relevant __printf attributes.

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
Acked-by: Petr Mladek <pmladek@xxxxxxxx>
---
v2: add __printf attribute to the definition of vprintk_nmi() which is
used when CONFIG_PRINTK_NMI is not defined.

kernel/printk/printk_safe.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 033e50a7d706..f96d1ecd85ac 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -80,8 +80,8 @@ static void queue_flush_work(struct printk_safe_seq_buf *s)
* happen, printk_safe_log_store() will notice the buffer->len mismatch
* and repeat the write.
*/
-static int printk_safe_log_store(struct printk_safe_seq_buf *s,
- const char *fmt, va_list args)
+static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s,
+ const char *fmt, va_list args)
{
int add;
size_t len;
@@ -299,7 +299,7 @@ void printk_safe_flush_on_panic(void)
* one writer running. But the buffer might get flushed from another
* CPU, so we need to be careful.
*/
-static int vprintk_nmi(const char *fmt, va_list args)
+static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)
{
struct printk_safe_seq_buf *s = this_cpu_ptr(&nmi_print_seq);

@@ -318,7 +318,7 @@ void printk_nmi_exit(void)

#else

-static int vprintk_nmi(const char *fmt, va_list args)
+static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)
{
return 0;
}
@@ -330,7 +330,7 @@ static int vprintk_nmi(const char *fmt, va_list args)
* into itself. It uses a per-CPU buffer to store the message, just like
* NMI.
*/
-static int vprintk_safe(const char *fmt, va_list args)
+static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args)
{
struct printk_safe_seq_buf *s = this_cpu_ptr(&safe_print_seq);

--
2.13.0