Hi Ted,
On Mon, Aug 27, 2018 at 7:23 AM, Theodore Ts'o <tytso@xxxxxxx> wrote:
> This suppresses some false positives in gcc 8's -Wstringop-truncation
>
> Suggested by Miguel Ojeda (hopefully the __nonstring definition will
> eventually get accepted in the compiler-gcc.h header file).
Thank you for checking it out! Whenever this gets merged, I will
update the __nonstring series with the #ifdef cleanup (as a second
example for the series and to avoid you worrying about the cleanup :-)
Cheers,
Miguel
>
> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
> Cc: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
> ---
> fs/ext4/ext4.h | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 1fc013f3d944..249bcee4d7b2 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -43,6 +43,17 @@
> #define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
> #include <linux/fscrypt.h>
>
> +#include <linux/compiler.h>
> +
> +/* Until this gets included into linux/compiler-gcc.h */
> +#ifndef __nonstring
> +#if defined(GCC_VERSION) && (GCC_VERSION >= 80000)
> +#define __nonstring __attribute__((nonstring))
> +#else
> +#define __nonstring
> +#endif
> +#endif
> +
> /*
> * The fourth extended filesystem constants/structures
> */
> @@ -1226,7 +1237,7 @@ struct ext4_super_block {
> __le32 s_feature_ro_compat; /* readonly-compatible feature set */
> /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
> /*78*/ char s_volume_name[16]; /* volume name */
> -/*88*/ char s_last_mounted[64]; /* directory where last mounted */
> +/*88*/ char s_last_mounted[64] __nonstring; /* directory where last mounted */
> /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */
> /*
> * Performance hints. Directory preallocation should only
> @@ -1277,13 +1288,13 @@ struct ext4_super_block {
> __le32 s_first_error_time; /* first time an error happened */
> __le32 s_first_error_ino; /* inode involved in first error */
> __le64 s_first_error_block; /* block involved of first error */
> - __u8 s_first_error_func[32]; /* function where the error happened */
> + __u8 s_first_error_func[32] __nonstring; /* function where the error happened */
> __le32 s_first_error_line; /* line number where error happened */
> __le32 s_last_error_time; /* most recent time of an error */
> __le32 s_last_error_ino; /* inode involved in last error */
> __le32 s_last_error_line; /* line number where error happened */
> __le64 s_last_error_block; /* block involved of last error */
> - __u8 s_last_error_func[32]; /* function where the error happened */
> + __u8 s_last_error_func[32] __nonstring; /* function where the error happened */
> #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
> __u8 s_mount_opts[64];
> __le32 s_usr_quota_inum; /* inode for tracking user quota */
> --
> 2.18.0.rc0
>
