include, lib: add __printf attributes to several function prototypes

Using __printf attributes helps to detect several format string issues
at compile time (even though -Wformat-security is currently disabled in
Makefile).  For example it can detect when formatting a pointer as a
number, like the issue fixed in commit a3fa71c40f18 ("wl18xx: show
rx_frames_per_rates as an array as it really is"), or when the arguments
do not match the format string, c.f.  for example commit 5ce1aca81435
("reiserfs: fix __RASSERT format string").

To prevent similar bugs in the future, add a __printf attribute to every
function prototype which needs one in include/linux/ and lib/.  These
functions were mostly found by using gcc's -Wsuggest-attribute=format
flag.

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h
index a240b18e86fa..08bffcc466de 100644
--- a/include/linux/clkdev.h
+++ b/include/linux/clkdev.h
@@ -33,18 +33,19 @@ struct clk_lookup {
 	}
 
 struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
-	const char *dev_fmt, ...);
+	const char *dev_fmt, ...) __printf(3, 4);
 
 void clkdev_add(struct clk_lookup *cl);
 void clkdev_drop(struct clk_lookup *cl);
 
 struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
-	const char *dev_fmt, ...);
+	const char *dev_fmt, ...) __printf(3, 4);
 
 void clkdev_add_table(struct clk_lookup *, size_t);
 int clk_add_alias(const char *, const char *, const char *, struct device *);
 
-int clk_register_clkdev(struct clk *, const char *, const char *, ...);
+int clk_register_clkdev(struct clk *, const char *, const char *, ...)
+	__printf(3, 4);
 int clk_register_clkdevs(struct clk *, struct clk_lookup *, size_t);
 
 #ifdef CONFIG_COMMON_CLK