[12/15] media: s5k5baf: avoid gcc-10 zero-length-bounds warning

Message ID 20200430213101.135134-13-arnd@arndb.de (mailing list archive)
State New
Delegated to: Sakari Ailus
Headers
Series gcc-10 warning fixes |

Commit Message

Arnd Bergmann April 30, 2020, 9:30 p.m. UTC
  gcc-10 warns about accessing a zero-length struct member:

drivers/media/i2c/s5k5baf.c: In function 's5k5baf_load_setfile':
drivers/media/i2c/s5k5baf.c:390:13: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'struct <anonymous>[0]' [-Wzero-length-bounds]
  390 |   if (f->seq[i].offset + d <= end)
      |       ~~~~~~^~~

This should really be a flexible-array member, but the structure
already has one. I experimentally confirmed that swapping the two
avoids the warning, as the 'data[]' array is not accessed like this.

Fixes: 3ba225b506a2 ("treewide: Replace zero-length array with flexible-array member")
Fixes: 7d459937dc09 ("[media] Add driver for Samsung S5K5BAF camera sensor")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/media/i2c/s5k5baf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
  

Comments

Gustavo A. R. Silva April 30, 2020, 9:46 p.m. UTC | #1
Hi Arnd,

On 4/30/20 16:30, Arnd Bergmann wrote:
> gcc-10 warns about accessing a zero-length struct member:
> 
> drivers/media/i2c/s5k5baf.c: In function 's5k5baf_load_setfile':
> drivers/media/i2c/s5k5baf.c:390:13: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'struct <anonymous>[0]' [-Wzero-length-bounds]
>   390 |   if (f->seq[i].offset + d <= end)
>       |       ~~~~~~^~~
> 
> This should really be a flexible-array member, but the structure
> already has one. I experimentally confirmed that swapping the two
> avoids the warning, as the 'data[]' array is not accessed like this.
> 
> Fixes: 3ba225b506a2 ("treewide: Replace zero-length array with flexible-array member")
> Fixes: 7d459937dc09 ("[media] Add driver for Samsung S5K5BAF camera sensor")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/media/i2c/s5k5baf.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/s5k5baf.c b/drivers/media/i2c/s5k5baf.c
> index 42584a088273..0b1ddedcf7dc 100644
> --- a/drivers/media/i2c/s5k5baf.c
> +++ b/drivers/media/i2c/s5k5baf.c
> @@ -277,11 +277,11 @@ enum {
>  
>  struct s5k5baf_fw {
>  	u16 count;
> +	u16 data[0];
>  	struct {
>  		u16 id;
>  		u16 offset;
> -	} seq[0];
> -	u16 data[];
> +	} seq[];
>  };
>  
>  struct s5k5baf {
> 

The treewide patch is an experimental change and, as this change only applies
to my -next tree, I will carry this patch in it, so other people don't have
to worry about this at all.

Thank you
--
Gustavo
  

Patch

diff --git a/drivers/media/i2c/s5k5baf.c b/drivers/media/i2c/s5k5baf.c
index 42584a088273..0b1ddedcf7dc 100644
--- a/drivers/media/i2c/s5k5baf.c
+++ b/drivers/media/i2c/s5k5baf.c
@@ -277,11 +277,11 @@  enum {
 
 struct s5k5baf_fw {
 	u16 count;
+	u16 data[0];
 	struct {
 		u16 id;
 		u16 offset;
-	} seq[0];
-	u16 data[];
+	} seq[];
 };
 
 struct s5k5baf {