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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-27 21:03:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-27 21:03:39 -0800
commitd12de1ef5eba3adb88f8e9dd81b6a60349466378 (patch)
treee7a82d5d797ba453ab16754a4750ec393773a2a1 /mm
parentba635f8cd20ebc7bddf1eb8e1f4eae28a034e916 (diff)
parentb3084f4db3aeb991c507ca774337c7e7893ed04f (diff)
downloadlinux-d12de1ef5eba3adb88f8e9dd81b6a60349466378.tar.gz
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc mremap fix from Ben Herrenschmidt: "This is the patch that I had sent after -rc8 and which we decided to wait before merging. It's based on a different tree than my -next branch (it needs some pre-reqs that were in -rc4 or so while my -next is based on -rc1) so I left it as a separate branch for your to pull. It's identical to the request I did 2 or 3 weeks back. This fixes crashes in mremap with THP on powerpc. The fix however requires a small change in the generic code. It moves a condition into a helper we can override from the arch which is harmless, but it *also* slightly changes the order of the set_pmd and the withdraw & deposit, which should be fine according to Kirill (who wrote that code) but I agree -rc8 is a bit late... It was acked by Kirill and Andrew told me to just merge it via powerpc" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/thp: Fix crash on mremap
Diffstat (limited to 'mm')
-rw-r--r--mm/huge_memory.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 65c98eb5483..82166bf974e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1508,19 +1508,15 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
VM_BUG_ON(!pmd_none(*new_pmd));
- set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
- if (new_ptl != old_ptl) {
- pgtable_t pgtable;
- /*
- * Move preallocated PTE page table if new_pmd is on
- * different PMD page table.
- */
+ if (pmd_move_must_withdraw(new_ptl, old_ptl)) {
+ pgtable_t pgtable;
pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
-
- spin_unlock(new_ptl);
}
+ set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
spin_unlock(old_ptl);
}
out: