Messages in this thread | | | Subject | Re: [PATCH v4 08/23] vfio, mm: fix get_user_pages_remote() and FOLL_LONGTERM | From | John Hubbard <> | Date | Wed, 13 Nov 2019 12:19:50 -0800 |
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On 11/13/19 11:17 AM, Ira Weiny wrote: ... >>> @@ -348,33 +347,13 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, >>> flags |= FOLL_WRITE; >>> >>> down_read(&mm->mmap_sem); >>> - if (mm == current->mm) { >>> - ret = get_user_pages(vaddr, 1, flags | FOLL_LONGTERM, page, >>> - vmas); >>> - } else { >>> - ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page, >>> - vmas, NULL); >>> - /* >>> - * The lifetime of a vaddr_get_pfn() page pin is >>> - * userspace-controlled. In the fs-dax case this could >>> - * lead to indefinite stalls in filesystem operations. >>> - * Disallow attempts to pin fs-dax pages via this >>> - * interface. >>> - */ >>> - if (ret > 0 && vma_is_fsdax(vmas[0])) { >>> - ret = -EOPNOTSUPP; >>> - put_page(page[0]); >>> - } >>> - } >>> - up_read(&mm->mmap_sem); >>> - >>> + ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, >>> + page, NULL, NULL); >>> if (ret == 1) { >>> *pfn = page_to_pfn(page[0]); >>> return 0; >> >> Mind the return with the lock held this needs some goto unwind > > Ah yea... retract my reviewed by... :-( >
ooops, embarrassed that I missed that, good catch. Will repost with it fixed.
thanks, -- John Hubbard NVIDIA
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