From 57a8f0cdb87da776bf0e4ce7554a9133854fa779 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 16 Oct 2013 13:47:09 -0700 Subject: [PATCH] mm: revert mremap pud_free anti-fix Revert commit 1ecfd533f4c5 ("mm/mremap.c: call pud_free() after fail calling pmd_alloc()"). The original code was correct: pud_alloc(), pmd_alloc(), pte_alloc_map() ensure that the pud, pmd, pt is already allocated, and seldom do they need to allocate; on failure, upper levels are freed if appropriate by the subsequent do_munmap(). Whereas commit 1ecfd533f4c5 did an unconditional pud_free() of a most-likely still-in-use pud: saved only by the near-impossiblity of pmd_alloc() failing. Signed-off-by: Hugh Dickins Cc: Chen Gang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mremap.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 91b13d6..0843feb 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -25,7 +25,6 @@ #include #include #include -#include #include "internal.h" @@ -63,10 +62,8 @@ static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma, return NULL; pmd = pmd_alloc(mm, pud, addr); - if (!pmd) { - pud_free(mm, pud); + if (!pmd) return NULL; - } VM_BUG_ON(pmd_trans_huge(*pmd)); -- 2.7.4