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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-27 21:03:39 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-27 21:03:39 -0800 |
| commit | d12de1ef5eba3adb88f8e9dd81b6a60349466378 (patch) | |
| tree | e7a82d5d797ba453ab16754a4750ec393773a2a1 /mm | |
| parent | ba635f8cd20ebc7bddf1eb8e1f4eae28a034e916 (diff) | |
| parent | b3084f4db3aeb991c507ca774337c7e7893ed04f (diff) | |
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.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 65c98eb5483c..82166bf974e1 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: |