[drm-tip:drm-tip 1291/1307] drivers/dma-buf/st-dma-resv.c:295:7: warning: variable 'i' is used uninitialized whenever 'if' condition is true

[kernel test robot]

tree:   git://anongit.freedesktop.org/drm/drm-tip drm-tip
head:   6eff63a9b932a4aa1e1f6e521cd919aaf57c058f
commit: 1d51775cd3f51899ce85afab686c7f641ff32d4e [1291/1307] dma-buf: add 
dma_resv selftest v4
config: arm-buildonly-randconfig-r006-20211025 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 
a461fa64bb37cffd73f683c74f6b0780379fc2ca)
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
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        git remote add drm-tip git://anongit.freedesktop.org/drm/drm-tip
        git fetch --no-tags drm-tip drm-tip
        git checkout 1d51775cd3f51899ce85afab686c7f641ff32d4e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 

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

All warnings (new ones prefixed by >>):

>> drivers/dma-buf/st-dma-resv.c:295:7: warning: variable 'i' is used 
>> uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
                   if (r) {
                       ^
   drivers/dma-buf/st-dma-resv.c:336:9: note: uninitialized use occurs here
           while (i--)
                  ^
   drivers/dma-buf/st-dma-resv.c:295:3: note: remove the 'if' if its condition 
is always false
                   if (r) {
                   ^~~~~~~~
   drivers/dma-buf/st-dma-resv.c:288:6: warning: variable 'i' is used 
uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (r) {
               ^
   drivers/dma-buf/st-dma-resv.c:336:9: note: uninitialized use occurs here
           while (i--)
                  ^
   drivers/dma-buf/st-dma-resv.c:288:2: note: remove the 'if' if its condition 
is always false
           if (r) {
           ^~~~~~~~
   drivers/dma-buf/st-dma-resv.c:280:10: note: initialize the variable 'i' to 
silence this warning
           int r, i;
                   ^
                    = 0
   2 warnings generated.


vim +295 drivers/dma-buf/st-dma-resv.c

   275  
   276  static int test_get_fences(void *arg, bool shared)
   277  {
   278          struct dma_fence *f, *excl = NULL, **fences = NULL;
   279          struct dma_resv resv;
   280          int r, i;
   281  
   282          f = alloc_fence();
   283          if (!f)
   284                  return -ENOMEM;
   285  
   286          dma_resv_init(&resv);
   287          r = dma_resv_lock(&resv, NULL);
   288          if (r) {
   289                  pr_err("Resv locking failed\n");
   290                  goto err_free;
   291          }
   292  
   293          if (shared) {
   294                  r = dma_resv_reserve_shared(&resv, 1);
 > 295                  if (r) {
   296                          pr_err("Resv shared slot allocation failed\n");
   297                          dma_resv_unlock(&resv);
   298                          goto err_free;
   299                  }
   300  
   301                  dma_resv_add_shared_fence(&resv, f);
   302          } else {
   303                  dma_resv_add_excl_fence(&resv, f);
   304          }
   305          dma_resv_unlock(&resv);
   306  
   307          r = dma_resv_get_fences(&resv, &excl, &i, &fences);
   308          if (r) {
   309                  pr_err("get_fences failed\n");
   310                  goto err_free;
   311          }
   312  
   313          if (shared) {
   314                  if (excl != NULL) {
   315                          pr_err("get_fences returned unexpected excl 
fence\n");
   316                          goto err_free;
   317                  }
   318                  if (i != 1 || fences[0] != f) {
   319                          pr_err("get_fences returned unexpected shared 
fence\n");
   320                          goto err_free;
   321                  }
   322          } else {
   323                  if (excl != f) {
   324                          pr_err("get_fences returned unexpected excl 
fence\n");
   325                          goto err_free;
   326                  }
   327                  if (i != 0) {
   328                          pr_err("get_fences returned unexpected shared 
fence\n");
   329                          goto err_free;
   330                  }
   331          }
   332  
   333          dma_fence_signal(f);
   334  err_free:
   335          dma_fence_put(excl);
   336          while (i--)
   337                  dma_fence_put(fences[i]);
   338          kfree(fences);
   339          dma_resv_fini(&resv);
   340          dma_fence_put(f);
   341          return r;
   342  }
   343  

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

.config.gz
Description: application/gzip