Re: [PATCH 6.15.y] mm/madvise: handle madvise_lock() failure during race unwinding

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 9c49e5d09f076001e05537734d7df002162eb2b5

Note: The patch differs from the upstream commit:
---
1:  9c49e5d09f076 ! 1:  0f9b85d494656 mm/madvise: handle madvise_lock() failure during race unwinding
    @@ Commit message
         Cc: Vlastimil Babka <vbabka@suse.cz>
         Cc: <stable@vger.kernel.org>
         Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    +    (cherry picked from commit 9c49e5d09f076001e05537734d7df002162eb2b5)
     
      ## mm/madvise.c ##
     @@ mm/madvise.c: static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
    + 
      			/* Drop and reacquire lock to unwind race. */
    - 			madvise_finish_tlb(&madv_behavior);
      			madvise_unlock(mm, behavior);
     -			madvise_lock(mm, behavior);
     +			ret = madvise_lock(mm, behavior);
     +			if (ret)
     +				goto out;
    - 			madvise_init_tlb(&madv_behavior, mm);
      			continue;
      		}
    + 		if (ret < 0)
     @@ mm/madvise.c: static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
    - 	madvise_finish_tlb(&madv_behavior);
    + 	}
      	madvise_unlock(mm, behavior);
      
     +out:
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.15.y       |  Success    |  Success   |