+++ /dev/null
-From b3084f4db3aeb991c507ca774337c7e7893ed04f Mon Sep 17 00:00:00 2001
-From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
-Date: Mon, 13 Jan 2014 11:34:24 +0530
-Subject: powerpc/thp: Fix crash on mremap
-
-From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
-
-commit b3084f4db3aeb991c507ca774337c7e7893ed04f upstream.
-
-This patch fix the below crash
-
-NIP [c00000000004cee4] .__hash_page_thp+0x2a4/0x440
-LR [c0000000000439ac] .hash_page+0x18c/0x5e0
-...
-Call Trace:
-[c000000736103c40] [00001ffffb000000] 0x1ffffb000000(unreliable)
-[437908.479693] [c000000736103d50] [c0000000000439ac] .hash_page+0x18c/0x5e0
-[437908.479699] [c000000736103e30] [c00000000000924c] .do_hash_page+0x4c/0x58
-
-On ppc64 we use the pgtable for storing the hpte slot information and
-store address to the pgtable at a constant offset (PTRS_PER_PMD) from
-pmd. On mremap, when we switch the pmd, we need to withdraw and deposit
-the pgtable again, so that we find the pgtable at PTRS_PER_PMD offset
-from new pmd.
-
-We also want to move the withdraw and deposit before the set_pmd so
-that, when page fault find the pmd as trans huge we can be sure that
-pgtable can be located at the offset.
-
-Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
-Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
-Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
-
----
- arch/Kconfig | 3 +++
- arch/powerpc/platforms/Kconfig.cputype | 1 +
- mm/huge_memory.c | 12 ++++++++++++
- 3 files changed, 16 insertions(+)
-
---- a/arch/Kconfig
-+++ b/arch/Kconfig
-@@ -365,6 +365,9 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE
- config HAVE_ARCH_SOFT_DIRTY
- bool
-
-+config ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW
-+ bool
-+
- config HAVE_MOD_ARCH_SPECIFIC
- bool
- help
---- a/arch/powerpc/platforms/Kconfig.cputype
-+++ b/arch/powerpc/platforms/Kconfig.cputype
-@@ -71,6 +71,7 @@ config PPC_BOOK3S_64
- select PPC_FPU
- select PPC_HAVE_PMU_SUPPORT
- select SYS_SUPPORTS_HUGETLBFS
-+ select ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW
- select HAVE_ARCH_TRANSPARENT_HUGEPAGE if PPC_64K_PAGES
-
- config PPC_BOOK3E_64
---- a/mm/huge_memory.c
-+++ b/mm/huge_memory.c
-@@ -1474,8 +1474,20 @@ int move_huge_pmd(struct vm_area_struct
-
- ret = __pmd_trans_huge_lock(old_pmd, vma);
- if (ret == 1) {
-+#ifdef CONFIG_ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW
-+ pgtable_t pgtable;
-+#endif
- pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
- VM_BUG_ON(!pmd_none(*new_pmd));
-+#ifdef CONFIG_ARCH_THP_MOVE_PMD_ALWAYS_WITHDRAW
-+ /*
-+ * Archs like ppc64 use pgtable to store per pmd
-+ * specific information. So when we switch the pmd,
-+ * we should also withdraw and deposit the pgtable
-+ */
-+ pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
-+ pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
-+#endif
- set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
- spin_unlock(&mm->page_table_lock);
- }
+++ /dev/null
-From b3084f4db3aeb991c507ca774337c7e7893ed04f Mon Sep 17 00:00:00 2001
-From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
-Date: Mon, 13 Jan 2014 11:34:24 +0530
-Subject: powerpc/thp: Fix crash on mremap
-
-From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
-
-commit b3084f4db3aeb991c507ca774337c7e7893ed04f upstream.
-
-This patch fix the below crash
-
-NIP [c00000000004cee4] .__hash_page_thp+0x2a4/0x440
-LR [c0000000000439ac] .hash_page+0x18c/0x5e0
-...
-Call Trace:
-[c000000736103c40] [00001ffffb000000] 0x1ffffb000000(unreliable)
-[437908.479693] [c000000736103d50] [c0000000000439ac] .hash_page+0x18c/0x5e0
-[437908.479699] [c000000736103e30] [c00000000000924c] .do_hash_page+0x4c/0x58
-
-On ppc64 we use the pgtable for storing the hpte slot information and
-store address to the pgtable at a constant offset (PTRS_PER_PMD) from
-pmd. On mremap, when we switch the pmd, we need to withdraw and deposit
-the pgtable again, so that we find the pgtable at PTRS_PER_PMD offset
-from new pmd.
-
-We also want to move the withdraw and deposit before the set_pmd so
-that, when page fault find the pmd as trans huge we can be sure that
-pgtable can be located at the offset.
-
-Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
-Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
-Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- arch/powerpc/include/asm/pgtable-ppc64.h | 14 ++++++++++++++
- include/asm-generic/pgtable.h | 12 ++++++++++++
- mm/huge_memory.c | 14 +++++---------
- 3 files changed, 31 insertions(+), 9 deletions(-)
-
---- a/arch/powerpc/include/asm/pgtable-ppc64.h
-+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
-@@ -558,5 +558,19 @@ extern pgtable_t pgtable_trans_huge_with
- #define __HAVE_ARCH_PMDP_INVALIDATE
- extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp);
-+
-+#define pmd_move_must_withdraw pmd_move_must_withdraw
-+typedef struct spinlock spinlock_t;
-+static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
-+ spinlock_t *old_pmd_ptl)
-+{
-+ /*
-+ * Archs like ppc64 use pgtable to store per pmd
-+ * specific information. So when we switch the pmd,
-+ * we should also withdraw and deposit the pgtable
-+ */
-+ return true;
-+}
-+
- #endif /* __ASSEMBLY__ */
- #endif /* _ASM_POWERPC_PGTABLE_PPC64_H_ */
---- a/include/asm-generic/pgtable.h
-+++ b/include/asm-generic/pgtable.h
-@@ -558,6 +558,18 @@ static inline pmd_t pmd_read_atomic(pmd_
- }
- #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
---- a/mm/huge_memory.c
-+++ b/mm/huge_memory.c
-@@ -1502,19 +1502,15 @@ int move_huge_pmd(struct vm_area_struct
- 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:
projects / thirdparty / kernel / stable-queue.git / commitdiff
