[gustavoars:testing/wfamnae-next20250124 14/15] include/linux/container_of.h:19:15: warning: 'fnode' is used uninitialized

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git testing/wfamnae-next20250124
head:   86b653e4edef7b0f7b7afe5dd8e0241fc1165238
commit: f66219294267a2fba220f4f3118e11c5cda63d0b [14/15] fs: hpfs: Avoid multiple -Wflex-array-member-not-at-end warnings
config: arm64-randconfig-001-20250127 (https://download.01.org/0day-ci/archive/20250127/202501272144.yqyXsRII-lkp@xxxxxxxxx/config)
compiler: aarch64-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250127/202501272144.yqyXsRII-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501272144.yqyXsRII-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from include/linux/list.h:5,
                    from include/linux/mutex.h:15,
                    from fs/hpfs/hpfs_fn.h:18,
                    from fs/hpfs/anode.c:10:
   fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
>> include/linux/container_of.h:19:15: warning: 'fnode' is used uninitialized [-Wuninitialized]
      19 |         void *__mptr = (void *)(ptr);                                   \
         |               ^~~~~~
   fs/hpfs/anode.c:74:44: note: in expansion of macro 'container_of'
      74 |         struct bplus_header *fnode_btree = container_of(&fnode->btree, struct bplus_header, __hdr);
         |                                            ^~~~~~~~~~~~
   fs/hpfs/anode.c:65:23: note: 'fnode' was declared here
      65 |         struct fnode *fnode;
         |                       ^~~~~


vim +/fnode +19 include/linux/container_of.h

d2a8ebbf8192b8 Andy Shevchenko  2021-11-08   9  
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  10  /**
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  11   * container_of - cast a member of a structure out to the containing structure
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  12   * @ptr:	the pointer to the member.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  13   * @type:	the type of the container struct this is embedded in.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  14   * @member:	the name of the member within the struct.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  15   *
7376e561fd2e01 Sakari Ailus     2022-10-24  16   * WARNING: any const qualifier of @ptr is lost.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  17   */
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  18  #define container_of(ptr, type, member) ({				\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08 @19  	void *__mptr = (void *)(ptr);					\
e1edc277e6f6df Rasmus Villemoes 2021-11-08  20  	static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\
e1edc277e6f6df Rasmus Villemoes 2021-11-08  21  		      __same_type(*(ptr), void),			\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  22  		      "pointer type mismatch in container_of()");	\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  23  	((type *)(__mptr - offsetof(type, member))); })
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  24  

:::::: The code at line 19 was first introduced by commit
:::::: d2a8ebbf8192b84b11f1b204c4f7c602df32aeac kernel.h: split out container_of() and typeof_member() macros

:::::: TO: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>

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