Commit 25eedabe authored Jan 17, 2016 by Linus Torvalds

vm: fix incorrect unlock error path in madvise_free_huge_pmd

Commit b8d3c4c3 ("mm/huge_memory.c: don't split THP page when
MADV_FREE syscall is called") introduced this new function, but got the
error handling for when pmd_trans_huge_lock() fails wrong.  In the
failure case, the lock has not been taken, and we should not unlock on
the way out.

Cc: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c671e1e3

mm/huge_memory.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1561,7 +1561,7 @@ int madvise_free_huge_pmd(struct mmu_gather tlb, struct vm_area_struct vma,
		int ret = 0;

		if (!pmd_trans_huge_lock(pmd, vma, &ptl))
		goto out;
		goto out_unlocked;

		orig_pmd = *pmd;
		if (is_huge_zero_pmd(orig_pmd)) {