[android-common:android15-6.6 1/1] fs/proc/vmcore.c:424:19: warning: 'mmap_vmcore_fault' defined but not used

Hi Qi,

FYI, the error/warning still remains.

tree:   https://android.googlesource.com/kernel/common android15-6.6
head:   cf8ba5678385b2b8832ed2e87c035925eb12bc4a
commit: 5b548fd0d2981f8ae80b7f07019d83d3536ba13f [1/1] fs/proc: fix compile warning about variable 'vmcore_mmap_ops'
config: arm-randconfig-r051-20260806 (https://download.01.org/0day-ci/archive/20260806/[email protected]/config)
compiler: arm-linux-gnueabi-gcc (GCC) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260806/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

>> fs/proc/vmcore.c:424:19: warning: 'mmap_vmcore_fault' defined but not used [-Wunused-function]
    static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
                      ^~~~~~~~~~~~~~~~~


vim +/mmap_vmcore_fault +424 fs/proc/vmcore.c

9cb218131de1c5 Michael Holzheu         2013-09-11  416  
9cb218131de1c5 Michael Holzheu         2013-09-11  417  /*
9cb218131de1c5 Michael Holzheu         2013-09-11  418   * The vmcore fault handler uses the page cache and fills data using the
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  419)  * standard __read_vmcore() function.
9cb218131de1c5 Michael Holzheu         2013-09-11  420   *
9cb218131de1c5 Michael Holzheu         2013-09-11  421   * On s390 the fault handler is used for memory regions that can't be mapped
9cb218131de1c5 Michael Holzheu         2013-09-11  422   * directly with remap_pfn_range().
9cb218131de1c5 Michael Holzheu         2013-09-11  423   */
36f062042b0fd9 Souptick Joarder        2018-08-21 @424  static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
9cb218131de1c5 Michael Holzheu         2013-09-11  425  {
9cb218131de1c5 Michael Holzheu         2013-09-11  426  #ifdef CONFIG_S390
11bac80004499e Dave Jiang              2017-02-24  427  	struct address_space *mapping = vmf->vma->vm_file->f_mapping;
9cb218131de1c5 Michael Holzheu         2013-09-11  428  	pgoff_t index = vmf->pgoff;
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  429) 	struct iov_iter iter;
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  430) 	struct kvec kvec;
9cb218131de1c5 Michael Holzheu         2013-09-11  431  	struct page *page;
9cb218131de1c5 Michael Holzheu         2013-09-11  432  	loff_t offset;
9cb218131de1c5 Michael Holzheu         2013-09-11  433  	int rc;
9cb218131de1c5 Michael Holzheu         2013-09-11  434  
9cb218131de1c5 Michael Holzheu         2013-09-11  435  	page = find_or_create_page(mapping, index, GFP_KERNEL);
9cb218131de1c5 Michael Holzheu         2013-09-11  436  	if (!page)
9cb218131de1c5 Michael Holzheu         2013-09-11  437  		return VM_FAULT_OOM;
9cb218131de1c5 Michael Holzheu         2013-09-11  438  	if (!PageUptodate(page)) {
09cbfeaf1a5a67 Kirill A. Shutemov      2016-04-01  439  		offset = (loff_t) index << PAGE_SHIFT;
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  440) 		kvec.iov_base = page_address(page);
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  441) 		kvec.iov_len = PAGE_SIZE;
de4eda9de2d957 Al Viro                 2022-09-15  442  		iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE);
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  443) 
4a22fd20379ca8 Matthew Wilcox (Oracle  2022-04-29  444) 		rc = __read_vmcore(&iter, &offset);
9cb218131de1c5 Michael Holzheu         2013-09-11  445  		if (rc < 0) {
9cb218131de1c5 Michael Holzheu         2013-09-11  446  			unlock_page(page);
09cbfeaf1a5a67 Kirill A. Shutemov      2016-04-01  447  			put_page(page);
b5c212374c8535 Souptick Joarder        2018-10-30  448  			return vmf_error(rc);
9cb218131de1c5 Michael Holzheu         2013-09-11  449  		}
9cb218131de1c5 Michael Holzheu         2013-09-11  450  		SetPageUptodate(page);
9cb218131de1c5 Michael Holzheu         2013-09-11  451  	}
9cb218131de1c5 Michael Holzheu         2013-09-11  452  	unlock_page(page);
9cb218131de1c5 Michael Holzheu         2013-09-11  453  	vmf->page = page;
9cb218131de1c5 Michael Holzheu         2013-09-11  454  	return 0;
9cb218131de1c5 Michael Holzheu         2013-09-11  455  #else
9cb218131de1c5 Michael Holzheu         2013-09-11  456  	return VM_FAULT_SIGBUS;
9cb218131de1c5 Michael Holzheu         2013-09-11  457  #endif
9cb218131de1c5 Michael Holzheu         2013-09-11  458  }
9cb218131de1c5 Michael Holzheu         2013-09-11  459  

:::::: The code at line 424 was first introduced by commit
:::::: 36f062042b0fd9f8e41b97a472f52139886ca26f fs/proc/vmcore.c: use new typedef vm_fault_t

:::::: TO: Souptick Joarder <[email protected]>
:::::: CC: Linus Torvalds <[email protected]>

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