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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 /include/asm-generic
parentba635f8cd20ebc7bddf1eb8e1f4eae28a034e916 (diff)
parentb3084f4db3aeb991c507ca774337c7e7893ed04f (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 'include/asm-generic')
-rw-r--r--include/asm-generic/pgtable.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index db0923458940..8e4f41d9af4d 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -558,6 +558,18 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
}
#endif
+#ifndef pmd_move_must_withdraw
+static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
+ spinlock_t *old_pmd_ptl)
+{
+ /*
+ * With split pmd lock we also need to move preallocated
+ * PTE page table if new_pmd is on different PMD page table.
+ */
+ return new_pmd_ptl != old_pmd_ptl;
+}
+#endif
+
/*
* This function is meant to be used by sites walking pagetables with
* the mmap_sem hold in read mode to protect against MADV_DONTNEED and