On Fri, Nov 13, 2020 at 01:58:48PM +0000, Matthew Wilcox wrote:
On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote:
+static vm_fault_t secretmem_fault(struct vm_fault *vmf) +{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- struct inode *inode = file_inode(vmf->vma->vm_file);
- pgoff_t offset = vmf->pgoff;
- unsigned long addr;
- struct page *page;
- int ret = 0;
- if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode))
return vmf_error(-EINVAL);- page = find_get_entry(mapping, offset);
Why did you decide to use find_get_entry() here? You don't handle swap or shadow entries.
Right, I've missed that.
- if (!page) {
page = secretmem_alloc_page(vmf->gfp_mask);if (!page)return vmf_error(-EINVAL);Why is this EINVAL and not ENOMEM?
Ah, I was annoyed by OOMs I got when I simulated various allocation failures, so I changed it to get SIGBUS instead and than forgot to restore. Will fix.
ret = add_to_page_cache(page, mapping, offset, vmf->gfp_mask);if (unlikely(ret))goto err_put_page;ret = set_direct_map_invalid_noflush(page, 1);if (ret)goto err_del_page_cache;addr = (unsigned long)page_address(page);flush_tlb_kernel_range(addr, addr + PAGE_SIZE);__SetPageUptodate(page);ret = VM_FAULT_LOCKED;- }
- vmf->page = page;
- return ret;
Does sparse not warn you about this abuse of vm_fault_t? Separate out 'ret' and 'err'.
Will fix.
Andrew, please fold in this fix. I suspect Mike will want to fix the other things I mention above.
diff --git a/mm/secretmem.c b/mm/secretmem.c index 3dfdbd85ba00..09ca27f21661 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -172,7 +172,7 @@ static vm_fault_t secretmem_fault(struct vm_fault *vmf) if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode)) return vmf_error(-EINVAL);
- page = find_get_entry(mapping, offset);
- page = find_get_page(mapping, offset); if (!page) { page = secretmem_alloc_page(ctx, vmf->gfp_mask); if (!page)