Re: [v2 PATCH 09/11] crypto: hash - Add sync hash interface

[kernel test robot <lkp@intel.com>]

Hi Herbert,

kernel test robot noticed the following build warnings:

[auto build test WARNING on herbert-cryptodev-2.6/master]
[also build test WARNING on next-20250214]
[cannot apply to herbert-crypto-2.6/master brauner-vfs/vfs.all linus/master v6.14-rc2]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Herbert-Xu/crypto-ahash-Only-save-callback-and-data-in-ahash_save_req/20250216-150941
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/d6e10dbf172f0b7c791f5406d55e8f1c74492d57.1739674648.git.herbert%40gondor.apana.org.au
patch subject: [v2 PATCH 09/11] crypto: hash - Add sync hash interface
config: um-randconfig-002-20250216 (https://download.01.org/0day-ci/archive/20250216/202502161850.W7NEHTk3-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250216/202502161850.W7NEHTk3-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502161850.W7NEHTk3-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/crypto/internal/hash.h:12,
                    from crypto/hash.h:10,
                    from crypto/ahash.c:26:
   In function 'ahash_request_set_callback',
       inlined from 'crypto_sync_hash_digest' at crypto/ahash.c:1153:2:
>> include/crypto/hash.h:690:18: warning: '*(struct ahash_request *)(&__req_req[0]).base.flags' is used uninitialized [-Wuninitialized]
     690 |         req->base.flags &= keep;
         |         ~~~~~~~~~^~~~~~
   crypto/ahash.c: In function 'crypto_sync_hash_digest':
   include/crypto/hash.h:183:14: note: '__req_req' declared here
     183 |         char __##name##_req[sizeof(struct ahash_request) + \
         |              ^~
   crypto/ahash.c:1150:9: note: in expansion of macro 'SYNC_HASH_REQUEST_ON_STACK'
    1150 |         SYNC_HASH_REQUEST_ON_STACK(req, tfm);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +690 include/crypto/hash.h

18e33e6d5cc049 Herbert Xu      2008-07-10  654  
90240ffb127729 Stephan Mueller 2014-11-12  655  /**
90240ffb127729 Stephan Mueller 2014-11-12  656   * ahash_request_set_callback() - set asynchronous callback function
90240ffb127729 Stephan Mueller 2014-11-12  657   * @req: request handle
90240ffb127729 Stephan Mueller 2014-11-12  658   * @flags: specify zero or an ORing of the flags
90240ffb127729 Stephan Mueller 2014-11-12  659   *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
90240ffb127729 Stephan Mueller 2014-11-12  660   *	   increase the wait queue beyond the initial maximum size;
90240ffb127729 Stephan Mueller 2014-11-12  661   *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
90240ffb127729 Stephan Mueller 2014-11-12  662   * @compl: callback function pointer to be registered with the request handle
90240ffb127729 Stephan Mueller 2014-11-12  663   * @data: The data pointer refers to memory that is not used by the kernel
90240ffb127729 Stephan Mueller 2014-11-12  664   *	  crypto API, but provided to the callback function for it to use. Here,
90240ffb127729 Stephan Mueller 2014-11-12  665   *	  the caller can provide a reference to memory the callback function can
90240ffb127729 Stephan Mueller 2014-11-12  666   *	  operate on. As the callback function is invoked asynchronously to the
90240ffb127729 Stephan Mueller 2014-11-12  667   *	  related functionality, it may need to access data structures of the
90240ffb127729 Stephan Mueller 2014-11-12  668   *	  related functionality which can be referenced using this pointer. The
90240ffb127729 Stephan Mueller 2014-11-12  669   *	  callback function can access the memory via the "data" field in the
90240ffb127729 Stephan Mueller 2014-11-12  670   *	  &crypto_async_request data structure provided to the callback function.
90240ffb127729 Stephan Mueller 2014-11-12  671   *
90240ffb127729 Stephan Mueller 2014-11-12  672   * This function allows setting the callback function that is triggered once
90240ffb127729 Stephan Mueller 2014-11-12  673   * the cipher operation completes.
90240ffb127729 Stephan Mueller 2014-11-12  674   *
90240ffb127729 Stephan Mueller 2014-11-12  675   * The callback function is registered with the &ahash_request handle and
0184cfe72d2f13 Stephan Mueller 2016-10-21  676   * must comply with the following template::
90240ffb127729 Stephan Mueller 2014-11-12  677   *
90240ffb127729 Stephan Mueller 2014-11-12  678   *	void callback_function(struct crypto_async_request *req, int error)
90240ffb127729 Stephan Mueller 2014-11-12  679   */
18e33e6d5cc049 Herbert Xu      2008-07-10  680  static inline void ahash_request_set_callback(struct ahash_request *req,
18e33e6d5cc049 Herbert Xu      2008-07-10  681  					      u32 flags,
3e3dc25fe7d5e3 Mark Rustad     2014-07-25  682  					      crypto_completion_t compl,
18e33e6d5cc049 Herbert Xu      2008-07-10  683  					      void *data)
18e33e6d5cc049 Herbert Xu      2008-07-10  684  {
07b1948dc8bac5 Herbert Xu      2025-02-16  685  	u32 keep = CRYPTO_AHASH_REQ_VIRT;
07b1948dc8bac5 Herbert Xu      2025-02-16  686  
3e3dc25fe7d5e3 Mark Rustad     2014-07-25  687  	req->base.complete = compl;
18e33e6d5cc049 Herbert Xu      2008-07-10  688  	req->base.data = data;
07b1948dc8bac5 Herbert Xu      2025-02-16  689  	flags &= ~keep;
07b1948dc8bac5 Herbert Xu      2025-02-16 @690  	req->base.flags &= keep;
07b1948dc8bac5 Herbert Xu      2025-02-16  691  	req->base.flags |= flags;
c0cd3e787da854 Herbert Xu      2025-02-16  692  	crypto_reqchain_init(&req->base);
18e33e6d5cc049 Herbert Xu      2008-07-10  693  }
18e33e6d5cc049 Herbert Xu      2008-07-10  694  

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