Re: [PATCH stable 5.15 v3] lib/buildid: Handle memfd_secret() files in build_id_parse()

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 5ac9b4e935dfc6af41eee2ddc21deb5c36507a9f

WARNING: Author mismatch between patch and upstream commit:
Backport author: Chen Linxuan<chenlinxuan@deepin.org>
Commit author: Andrii Nakryiko<andrii@kernel.org>

Status in newer kernel trees:
6.13.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Not found
6.1.y | Not found

Note: The patch differs from the upstream commit:
---
1:  5ac9b4e935dfc ! 1:  dbfb55637bbbe lib/buildid: Handle memfd_secret() files in build_id_parse()
    @@
      ## Metadata ##
    -Author: Andrii Nakryiko <andrii@kernel.org>
    +Author: Chen Linxuan <chenlinxuan@deepin.org>
     
      ## Commit message ##
         lib/buildid: Handle memfd_secret() files in build_id_parse()
     
    +    [ Upstream commit 5ac9b4e935dfc6af41eee2ddc21deb5c36507a9f ]
    +
         >From memfd_secret(2) manpage:
     
           The memory areas backing the file created with memfd_secret(2) are
    @@ Commit message
         Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
         Link: https://lore.kernel.org/bpf/20241017175431.6183-A-hca@linux.ibm.com
         Link: https://lore.kernel.org/bpf/20241017174713.2157873-1-andrii@kernel.org
    +    [ Chen Linxuan: backport same logic without folio-based changes ]
    +    Cc: stable@vger.kernel.org
    +    Fixes: 88a16a130933 ("perf: Add build id data in mmap2 event")
    +    Signed-off-by: Chen Linxuan <chenlinxuan@deepin.org>
     
      ## lib/buildid.c ##
     @@
    @@ lib/buildid.c
      
      #define BUILD_ID 3
      
    -@@ lib/buildid.c: static int freader_get_folio(struct freader *r, loff_t file_off)
    - 
    - 	freader_put_folio(r);
    +@@ lib/buildid.c: int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
    + 	if (!vma->vm_file)
    + 		return -EINVAL;
      
     +	/* reject secretmem folios created with memfd_secret() */
    -+	if (secretmem_mapping(r->file->f_mapping))
    ++	if (vma_is_secretmem(vma))
     +		return -EFAULT;
     +
    - 	r->folio = filemap_get_folio(r->file->f_mapping, file_off >> PAGE_SHIFT);
    - 
    - 	/* if sleeping is allowed, wait for the page, if necessary */
    + 	page = find_get_page(vma->vm_file->f_mapping, 0);
    + 	if (!page)
    + 		return -EFAULT;	/* page not mapped */
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |