[8/9] ALSA: aoa: avoid false-positive format truncation warning

Commit Message

Arnd Bergmann March 26, 2024, 10:38 p.m. UTC

From: Arnd Bergmann <[e-mail]>

clang warns about what it interprets as a truncated snprintf:

sound/aoa/soundbus/i2sbus/core.c:171:6: error: 'snprintf' will always be truncated; specified size is 6, but format string expands to at least 7 [-Werror,-Wformat-truncation-non-kprintf]

The actual problem here is that it does not understand the special
%pOFn format string and assumes that it is a pointer followed by
the string "OFn", which would indeed not fit.

Slightly increasing the size of the buffer to its natural alignment
avoids the warning, as it is now long enough for the correct and
the incorrect interprations.

Fixes: b917d58dcfaa ("ALSA: aoa: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Arnd Bergmann <[e-mail]>
---
 sound/aoa/soundbus/i2sbus/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Takashi Iwai March 27, 2024, 9:54 a.m. UTC | #1

On Tue, 26 Mar 2024 23:38:07 +0100,
Arnd Bergmann wrote:
> 
> From: Arnd Bergmann <[e-mail]>
> 
> clang warns about what it interprets as a truncated snprintf:
> 
> sound/aoa/soundbus/i2sbus/core.c:171:6: error: 'snprintf' will always be truncated; specified size is 6, but format string expands to at least 7 [-Werror,-Wformat-truncation-non-kprintf]
> 
> The actual problem here is that it does not understand the special
> %pOFn format string and assumes that it is a pointer followed by
> the string "OFn", which would indeed not fit.
> 
> Slightly increasing the size of the buffer to its natural alignment
> avoids the warning, as it is now long enough for the correct and
> the incorrect interprations.
> 
> Fixes: b917d58dcfaa ("ALSA: aoa: Convert to using %pOFn instead of device_node.name")
> Signed-off-by: Arnd Bergmann <[e-mail]>

Applied this one now to sound.git tree.  Thanks.


Takashi

Patch

diff --git a/sound/aoa/soundbus/i2sbus/core.c b/sound/aoa/soundbus/i2sbus/core.c
index b8ff5cccd0c8..5431d2c49421 100644
--- a/sound/aoa/soundbus/i2sbus/core.c
+++ b/sound/aoa/soundbus/i2sbus/core.c
@@ -158,7 +158,7 @@  static int i2sbus_add_dev(struct macio_dev *macio,
 	struct device_node *child, *sound = NULL;
 	struct resource *r;
 	int i, layout = 0, rlen, ok = force;
-	char node_name[6];
+	char node_name[8];
 	static const char *rnames[] = { "i2sbus: %pOFn (control)",
 					"i2sbus: %pOFn (tx)",
 					"i2sbus: %pOFn (rx)" };