sound/pci/cmipci.c:3235:2: warning: Value stored to 'cm' is never read [clang-analyzer-deadcode.DeadStores]

* sound/pci/cmipci.c:3235:2: warning: Value stored to 'cm' is never read [clang-analyzer-deadcode.DeadStores]
@ 2021-11-08  5:03 kernel test robot
  2021-11-12  8:27   ` kernel test robot
  0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2021-11-08  5:03 UTC (permalink / raw)
  To: kbuild

[-- Attachment #1: Type: text/plain, Size: 18282 bytes --]

CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Takashi Iwai <tiwai@suse.de>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   6b75d88fa81b122cce37ebf17428a849ccd3d0f1
commit: 87e082ad84a7e1f022be168396ff1cb93a80c557 ALSA: cmipci: Allocate resources with device-managed APIs
date:   4 months ago
:::::: branch date: 10 hours ago
:::::: commit date: 4 months ago
config: i386-randconfig-c001-20211012 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c3dcf39554dbea780d6cb7e12239451ba47a2668)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=87e082ad84a7e1f022be168396ff1cb93a80c557
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 87e082ad84a7e1f022be168396ff1cb93a80c557
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=i386 clang-analyzer 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)
   include/linux/stddef.h:8:14: note: expanded from macro 'NULL'
   #define NULL ((void *)0)
                ^~~~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_userptr.c:385:8: note: Calling 'i915_gem_object_lock_interruptible'
           err = i915_gem_object_lock_interruptible(obj, NULL);
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:192:10: note: 'ww' is null
           WARN_ON(ww && !ww->intr);
                   ^
   drivers/gpu/drm/i915/i915_utils.h:48:26: note: expanded from macro 'WARN_ON'
   #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
                            ^
   include/asm-generic/bug.h:130:25: note: expanded from macro 'WARN'
           int __ret_warn_on = !!(condition);                              \
                                  ^~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:192:13: note: Left side of '&&' is false
           WARN_ON(ww && !ww->intr);
                      ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:192:2: note: Taking false branch
           WARN_ON(ww && !ww->intr);
           ^
   drivers/gpu/drm/i915/i915_utils.h:48:20: note: expanded from macro 'WARN_ON'
   #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
                      ^
   include/asm-generic/bug.h:131:2: note: expanded from macro 'WARN'
           if (unlikely(__ret_warn_on))                                    \
           ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:193:37: note: Passing null pointer value via 2nd parameter 'ww'
           return __i915_gem_object_lock(obj, ww, true);
                                              ^~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:193:9: note: Calling '__i915_gem_object_lock'
           return __i915_gem_object_lock(obj, ww, true);
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:167:6: note: 'intr' is true
           if (intr)
               ^~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:167:2: note: Taking true branch
           if (intr)
           ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:168:53: note: 'ww' is null
                   ret = dma_resv_lock_interruptible(obj->base.resv, ww ? &ww->ctx : NULL);
                                                                     ^~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:168:53: note: '?' condition is false
   drivers/gpu/drm/i915/gem/i915_gem_object.h:172:6: note: Assuming 'ret' is not equal to 0
           if (!ret && ww)
               ^~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:172:11: note: Left side of '&&' is false
           if (!ret && ww)
                    ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:174:6: note: Assuming the condition is false
           if (ret == -EALREADY)
               ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:174:2: note: Taking false branch
           if (ret == -EALREADY)
           ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:177:6: note: Assuming the condition is true
           if (ret == -EDEADLK)
               ^~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/gem/i915_gem_object.h:177:2: note: Taking true branch
           if (ret == -EDEADLK)
           ^
   drivers/gpu/drm/i915/gem/i915_gem_object.h:178:17: note: Access to field 'contended' results in a dereference of a null pointer (loaded from variable 'ww')
                   ww->contended = obj;
                   ~~            ^
   drivers/gpu/drm/i915/gem/i915_gem_userptr.c:320:11: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret' [clang-analyzer-deadcode.DeadStores]
           pinned = ret = 0;
                    ^     ~
   drivers/gpu/drm/i915/gem/i915_gem_userptr.c:320:11: note: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret'
           pinned = ret = 0;
                    ^     ~
   Suppressed 9 warnings (9 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   10 warnings generated.
   sound/pci/azt3328.c:2109:2: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
           strcpy(pcm->name, chip->card->shortname);
           ^~~~~~
   sound/pci/azt3328.c:2109:2: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
           strcpy(pcm->name, chip->card->shortname);
           ^~~~~~
   sound/pci/azt3328.c:2126:2: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
           strcpy(pcm->name, chip->card->shortname);
           ^~~~~~
   sound/pci/azt3328.c:2126:2: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
           strcpy(pcm->name, chip->card->shortname);
           ^~~~~~
   Suppressed 8 warnings (7 in non-user code, 1 with check filters).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   10 warnings generated.
   sound/pci/cmipci.c:2742:3: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
                   strcpy(elem_id.name, cm_saved_mixer[idx].name);
                   ^~~~~~
   sound/pci/cmipci.c:2742:3: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
                   strcpy(elem_id.name, cm_saved_mixer[idx].name);
                   ^~~~~~
   sound/pci/cmipci.c:3036:3: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy]
                   strcpy(cm->card->driver + strlen(cm->card->driver), "-SWIEC");
                   ^~~~~~
   sound/pci/cmipci.c:3036:3: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119
                   strcpy(cm->card->driver + strlen(cm->card->driver), "-SWIEC");
                   ^~~~~~
>> sound/pci/cmipci.c:3235:2: warning: Value stored to 'cm' is never read [clang-analyzer-deadcode.DeadStores]
           cm = card->private_data;
           ^    ~~~~~~~~~~~~~~~~~~
   sound/pci/cmipci.c:3235:2: note: Value stored to 'cm' is never read
           cm = card->private_data;
           ^    ~~~~~~~~~~~~~~~~~~
   Suppressed 7 warnings (7 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   7 warnings generated.
   Suppressed 7 warnings (7 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   6 warnings generated.
   Suppressed 6 warnings (6 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   7 warnings generated.
   Suppressed 7 warnings (7 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   6 warnings generated.
   Suppressed 6 warnings (6 in non-user code).
   Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
   9 warnings generated.
   include/linux/list.h:135:13: warning: Use of memory after it is freed [clang-analyzer-unix.Malloc]
           __list_del(entry->prev, entry->next);
                      ^
   sound/virtio/virtio_ctl_msg.c:238:2: note: Loop condition is false.  Exiting loop
           spin_lock_irqsave(&queue->lock, flags);
           ^
   include/linux/spinlock.h:384:2: note: expanded from macro 'spin_lock_irqsave'
           raw_spin_lock_irqsave(spinlock_check(lock), flags);     \
           ^
   include/linux/spinlock.h:250:2: note: expanded from macro 'raw_spin_lock_irqsave'
           do {                                            \
           ^
   sound/virtio/virtio_ctl_msg.c:238:2: note: Loop condition is false.  Exiting loop
           spin_lock_irqsave(&queue->lock, flags);
           ^
   include/linux/spinlock.h:382:43: note: expanded from macro 'spin_lock_irqsave'
   #define spin_lock_irqsave(lock, flags)                          \
                                                                   ^
   sound/virtio/virtio_ctl_msg.c:239:2: note: Loop condition is true.  Entering loop body
           while (!list_empty(&snd->ctl_msgs)) {
           ^
   sound/virtio/virtio_ctl_msg.c:241:4: note: Left side of '&&' is false
                           list_first_entry(&snd->ctl_msgs, struct virtio_snd_msg,
                           ^
   include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
           list_entry((ptr)->next, type, member)
           ^
   include/linux/list.h:511:2: note: expanded from macro 'list_entry'
           container_of(ptr, type, member)
           ^
   include/linux/kernel.h:495:61: note: expanded from macro 'container_of'
           BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
                                                                      ^
   sound/virtio/virtio_ctl_msg.c:241:4: note: Taking false branch
                           list_first_entry(&snd->ctl_msgs, struct virtio_snd_msg,
                           ^
   include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
           list_entry((ptr)->next, type, member)
           ^
   include/linux/list.h:511:2: note: expanded from macro 'list_entry'
           container_of(ptr, type, member)
           ^
   include/linux/kernel.h:495:2: note: expanded from macro 'container_of'
           BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
           ^
   note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:328:2: note: expanded from macro 'compiletime_assert'
           _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
           ^
   include/linux/compiler_types.h:316:2: note: expanded from macro '_compiletime_assert'
           __compiletime_assert(condition, msg, prefix, suffix)
           ^
   include/linux/compiler_types.h:308:3: note: expanded from macro '__compiletime_assert'
                   if (!(condition))                                       \
                   ^
   sound/virtio/virtio_ctl_msg.c:241:4: note: Loop condition is false.  Exiting loop
                           list_first_entry(&snd->ctl_msgs, struct virtio_snd_msg,
                           ^
   include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
           list_entry((ptr)->next, type, member)
           ^
   include/linux/list.h:511:2: note: expanded from macro 'list_entry'
           container_of(ptr, type, member)
           ^
   include/linux/kernel.h:495:2: note: expanded from macro 'container_of'
           BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
           ^
   note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:328:2: note: expanded from macro 'compiletime_assert'
           _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
           ^
   include/linux/compiler_types.h:316:2: note: expanded from macro '_compiletime_assert'
           __compiletime_assert(condition, msg, prefix, suffix)
           ^
   include/linux/compiler_types.h:306:2: note: expanded from macro '__compiletime_assert'
           do {                                                            \
           ^
   sound/virtio/virtio_ctl_msg.c:244:3: note: Calling 'virtsnd_ctl_msg_complete'
                   virtsnd_ctl_msg_complete(msg);
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/cm +3235 sound/pci/cmipci.c

^1da177e4c3f41 Linus Torvalds 2005-04-16  3215  
e23e7a14362072 Bill Pemberton 2012-12-06  3216  static int snd_cmipci_probe(struct pci_dev *pci,
^1da177e4c3f41 Linus Torvalds 2005-04-16  3217  			    const struct pci_device_id *pci_id)
^1da177e4c3f41 Linus Torvalds 2005-04-16  3218  {
^1da177e4c3f41 Linus Torvalds 2005-04-16  3219  	static int dev;
2cbdb686dd8df8 Takashi Iwai   2005-11-17  3220  	struct snd_card *card;
2cbdb686dd8df8 Takashi Iwai   2005-11-17  3221  	struct cmipci *cm;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3222  	int err;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3223  
^1da177e4c3f41 Linus Torvalds 2005-04-16  3224  	if (dev >= SNDRV_CARDS)
^1da177e4c3f41 Linus Torvalds 2005-04-16  3225  		return -ENODEV;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3226  	if (! enable[dev]) {
^1da177e4c3f41 Linus Torvalds 2005-04-16  3227  		dev++;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3228  		return -ENOENT;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3229  	}
^1da177e4c3f41 Linus Torvalds 2005-04-16  3230  
87e082ad84a7e1 Takashi Iwai   2021-07-15  3231  	err = snd_devm_card_new(&pci->dev, index[dev], id[dev], THIS_MODULE,
87e082ad84a7e1 Takashi Iwai   2021-07-15  3232  				sizeof(*cm), &card);
e58de7baf7de11 Takashi Iwai   2008-12-28  3233  	if (err < 0)
e58de7baf7de11 Takashi Iwai   2008-12-28  3234  		return err;
87e082ad84a7e1 Takashi Iwai   2021-07-15 @3235  	cm = card->private_data;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3236  	
^1da177e4c3f41 Linus Torvalds 2005-04-16  3237  	switch (pci->device) {
^1da177e4c3f41 Linus Torvalds 2005-04-16  3238  	case PCI_DEVICE_ID_CMEDIA_CM8738:
^1da177e4c3f41 Linus Torvalds 2005-04-16  3239  	case PCI_DEVICE_ID_CMEDIA_CM8738B:
^1da177e4c3f41 Linus Torvalds 2005-04-16  3240  		strcpy(card->driver, "CMI8738");
^1da177e4c3f41 Linus Torvalds 2005-04-16  3241  		break;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3242  	case PCI_DEVICE_ID_CMEDIA_CM8338A:
^1da177e4c3f41 Linus Torvalds 2005-04-16  3243  	case PCI_DEVICE_ID_CMEDIA_CM8338B:
^1da177e4c3f41 Linus Torvalds 2005-04-16  3244  		strcpy(card->driver, "CMI8338");
^1da177e4c3f41 Linus Torvalds 2005-04-16  3245  		break;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3246  	default:
^1da177e4c3f41 Linus Torvalds 2005-04-16  3247  		strcpy(card->driver, "CMIPCI");
^1da177e4c3f41 Linus Torvalds 2005-04-16  3248  		break;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3249  	}
^1da177e4c3f41 Linus Torvalds 2005-04-16  3250  
87e082ad84a7e1 Takashi Iwai   2021-07-15  3251  	err = snd_cmipci_create(card, pci, dev);
e17a85eccfa0b7 Markus Elfring 2017-08-22  3252  	if (err < 0)
87e082ad84a7e1 Takashi Iwai   2021-07-15  3253  		return err;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3254  
e17a85eccfa0b7 Markus Elfring 2017-08-22  3255  	err = snd_card_register(card);
e17a85eccfa0b7 Markus Elfring 2017-08-22  3256  	if (err < 0)
87e082ad84a7e1 Takashi Iwai   2021-07-15  3257  		return err;
e17a85eccfa0b7 Markus Elfring 2017-08-22  3258  
^1da177e4c3f41 Linus Torvalds 2005-04-16  3259  	pci_set_drvdata(pci, card);
^1da177e4c3f41 Linus Torvalds 2005-04-16  3260  	dev++;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3261  	return 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16  3262  }
^1da177e4c3f41 Linus Torvalds 2005-04-16  3263  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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