drivers/dma-buf/heaps/system_heap.c:357:10: warning: incompatible integer to pointer conversion returning 'int' from a function with result type 'struct dma_buf *'

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

tree:   https://github.com/0day-ci/linux/commits/UPDATE-20220120-113516/guangming-cao-mediatek-com/dma-buf-dma-heap-Add-a-size-limitation-for-allocation/20211217-174135
head:   d6d3f09d899553b1100b195a91a8f718d1bd6bc2
commit: d6d3f09d899553b1100b195a91a8f718d1bd6bc2 dma-buf: system_heap: Add a size check for allocation
date:   3 hours ago
config: x86_64-randconfig-a001-20220117 (https://download.01.org/0day-ci/archive/20220120/202201201459.LzpimBE3-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f7b7138a62648f4019c55e4671682af1f851f295)
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://github.com/0day-ci/linux/commit/d6d3f09d899553b1100b195a91a8f718d1bd6bc2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review UPDATE-20220120-113516/guangming-cao-mediatek-com/dma-buf-dma-heap-Add-a-size-limitation-for-allocation/20211217-174135
        git checkout d6d3f09d899553b1100b195a91a8f718d1bd6bc2
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/dma-buf/heaps/

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

All warnings (new ones prefixed by >>):

>> drivers/dma-buf/heaps/system_heap.c:357:10: warning: incompatible integer to pointer conversion returning 'int' from a function with result type 'struct dma_buf *' [-Wint-conversion]
                   return -EINVAL;
                          ^~~~~~~
   1 warning generated.


vim +357 drivers/dma-buf/heaps/system_heap.c

   334	
   335	static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
   336						    unsigned long len,
   337						    unsigned long fd_flags,
   338						    unsigned long heap_flags)
   339	{
   340		struct system_heap_buffer *buffer;
   341		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
   342		unsigned long size_remaining = len;
   343		unsigned int max_order = orders[0];
   344		struct dma_buf *dmabuf;
   345		struct sg_table *table;
   346		struct scatterlist *sg;
   347		struct list_head pages;
   348		struct page *page, *tmp_page;
   349		int i, ret = -ENOMEM;
   350	
   351		/*
   352		 * Size check. The "len" should be less than totalram since system_heap
   353		 * memory is comes from system. Adding check here can prevent consuming
   354		 * too much time for invalid allocations.
   355		 */
   356		if (len >> PAGE_SHIFT > totalram_pages())
 > 357			return -EINVAL;
   358		buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
   359		if (!buffer)
   360			return ERR_PTR(-ENOMEM);
   361	
   362		INIT_LIST_HEAD(&buffer->attachments);
   363		mutex_init(&buffer->lock);
   364		buffer->heap = heap;
   365		buffer->len = len;
   366	
   367		INIT_LIST_HEAD(&pages);
   368		i = 0;
   369		while (size_remaining > 0) {
   370			/*
   371			 * Avoid trying to allocate memory if the process
   372			 * has been killed by SIGKILL
   373			 */
   374			if (fatal_signal_pending(current)) {
   375				ret = -EINTR;
   376				goto free_buffer;
   377			}
   378	
   379			page = alloc_largest_available(size_remaining, max_order);
   380			if (!page)
   381				goto free_buffer;
   382	
   383			list_add_tail(&page->lru, &pages);
   384			size_remaining -= page_size(page);
   385			max_order = compound_order(page);
   386			i++;
   387		}
   388	
   389		table = &buffer->sg_table;
   390		if (sg_alloc_table(table, i, GFP_KERNEL))
   391			goto free_buffer;
   392	
   393		sg = table->sgl;
   394		list_for_each_entry_safe(page, tmp_page, &pages, lru) {
   395			sg_set_page(sg, page, page_size(page), 0);
   396			sg = sg_next(sg);
   397			list_del(&page->lru);
   398		}
   399	
   400		/* create the dmabuf */
   401		exp_info.exp_name = dma_heap_get_name(heap);
   402		exp_info.ops = &system_heap_buf_ops;
   403		exp_info.size = buffer->len;
   404		exp_info.flags = fd_flags;
   405		exp_info.priv = buffer;
   406		dmabuf = dma_buf_export(&exp_info);
   407		if (IS_ERR(dmabuf)) {
   408			ret = PTR_ERR(dmabuf);
   409			goto free_pages;
   410		}
   411		return dmabuf;
   412	
   413	free_pages:
   414		for_each_sgtable_sg(table, sg, i) {
   415			struct page *p = sg_page(sg);
   416	
   417			__free_pages(p, compound_order(p));
   418		}
   419		sg_free_table(table);
   420	free_buffer:
   421		list_for_each_entry_safe(page, tmp_page, &pages, lru)
   422			__free_pages(page, compound_order(page));
   423		kfree(buffer);
   424	
   425		return ERR_PTR(ret);
   426	}
   427	

---
0-DAY CI Kernel Test Service, Intel Corporation
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