add-nonstring-annotations-to-ext4.h

   1 ext4: add nonstring annotations to ext4.h
   2
   3 This suppresses some false positives in gcc 8's -Wstringop-truncation
   4
   5 Suggested by Miguel Ojeda (hopefully the __nonstring definition will
   6 eventually get accepted in the compiler-gcc.h header file).
   7
   8 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   9 Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
  10 ---
  11  fs/ext4/ext4.h | 17 ++++++++++++++---
  12  1 file changed, 14 insertions(+), 3 deletions(-)
  13
  14 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  15 index 1fc013f3d944..249bcee4d7b2 100644
  16 --- a/fs/ext4/ext4.h
  17 +++ b/fs/ext4/ext4.h
  18 @@ -43,6 +43,17 @@
  19  #define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
  20  #include <linux/fscrypt.h>
  21
  22 +#include <linux/compiler.h>
  23 +
  24 +/* Until this gets included into linux/compiler-gcc.h */
  25 +#ifndef __nonstring
  26 +#if defined(GCC_VERSION) && (GCC_VERSION >= 80000)
  27 +#define __nonstring __attribute__((nonstring))
  28 +#else
  29 +#define __nonstring
  30 +#endif
  31 +#endif
  32 +
  33  /*
  34   * The fourth extended filesystem constants/structures
  35   */
  36 @@ -1226,7 +1237,7 @@ struct ext4_super_block {
  37         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
  38  /*68*/ __u8    s_uuid[16];             /* 128-bit uuid for volume */
  39  /*78*/ char    s_volume_name[16];      /* volume name */
  40 -/*88*/ char    s_last_mounted[64];     /* directory where last mounted */
  41 +/*88*/ char    s_last_mounted[64] __nonstring; /* directory where last mounted */
  42  /*C8*/ __le32  s_algorithm_usage_bitmap; /* For compression */
  43         /*
  44          * Performance hints.  Directory preallocation should only
  45 @@ -1277,13 +1288,13 @@ struct ext4_super_block {
  46         __le32  s_first_error_time;     /* first time an error happened */
  47         __le32  s_first_error_ino;      /* inode involved in first error */
  48         __le64  s_first_error_block;    /* block involved of first error */
  49 -       __u8    s_first_error_func[32]; /* function where the error happened */
  50 +       __u8    s_first_error_func[32] __nonstring;     /* function where the error happened */
  51         __le32  s_first_error_line;     /* line number where error happened */
  52         __le32  s_last_error_time;      /* most recent time of an error */
  53         __le32  s_last_error_ino;       /* inode involved in last error */
  54         __le32  s_last_error_line;      /* line number where error happened */
  55         __le64  s_last_error_block;     /* block involved of last error */
  56 -       __u8    s_last_error_func[32];  /* function where the error happened */
  57 +       __u8    s_last_error_func[32] __nonstring;      /* function where the error happened */
  58  #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
  59         __u8    s_mount_opts[64];
  60         __le32  s_usr_quota_inum;       /* inode for tracking user quota */