[rppt:uffd/refactor/v0.2 8/11] mm/userfaultfd.c:589:7: warning: variable 'ret' is uninitialized when used here

[rppt:uffd/refactor/v0.2 8/11] mm/userfaultfd.c:589:7: warning: variable 'ret' is uninitialized when used here

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git uffd/refactor/v0.2
head:   2db3a86a6de3247449e068d998305d26481c5522
commit: 629131e835ff52775f59108aa49795ce35e442d4 [8/11] userfaultfd, shmem: use a VMA callback to handle UFFDIO_CONTINUE
config: x86_64-randconfig-016-20260119 (https://download.01.org/0day-ci/archive/20260119/202601190850.lPsTWmiG-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260119/202601190850.lPsTWmiG-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/202601190850.lPsTWmiG-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/userfaultfd.c:589:7: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
     589 |                 if (ret == -ENOENT || !folio)
         |                     ^~~
   mm/userfaultfd.c:581:9: note: initialize the variable 'ret' to silence this warning
     581 |         int ret;
         |                ^
         |                 = 0
   1 warning generated.


vim +/ret +589 mm/userfaultfd.c

   568	
   569	/* Handles UFFDIO_CONTINUE for all shmem VMAs (shared or private). */
   570	static int mfill_atomic_pte_continue(struct mfill_state *state)
   571	{
   572		struct vm_area_struct *dst_vma = state->vma;
   573		const struct vm_uffd_ops *ops = vma_uffd_ops(dst_vma);
   574		unsigned long dst_addr = state->dst_addr;
   575		pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
   576		struct inode *inode = file_inode(dst_vma->vm_file);
   577		uffd_flags_t flags = state->flags;
   578		pmd_t *dst_pmd = state->pmd;
   579		struct folio *folio;
   580		struct page *page;
   581		int ret;
   582	
   583		if (!ops)
   584			return -EOPNOTSUPP;
   585	
   586		folio = ops->get_folio_noalloc(inode, pgoff);
   587		/* Our caller expects us to return -EFAULT if we failed to find folio */
   588		if (IS_ERR_OR_NULL(folio)) {
 > 589			if (ret == -ENOENT || !folio)
   590				ret = -EFAULT;
   591			return -EFAULT;
   592		}
   593	
   594		page = folio_file_page(folio, pgoff);
   595		if (PageHWPoison(page)) {
   596			ret = -EIO;
   597			goto out_release;
   598		}
   599	
   600		ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr,
   601					       page, false, flags);
   602		if (ret)
   603			goto out_release;
   604	
   605		folio_unlock(folio);
   606		return 0;
   607	
   608	out_release:
   609		folio_unlock(folio);
   610		folio_put(folio);
   611		return ret;
   612	}
   613	

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