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authorLinus Torvalds <torvalds@linux-foundation.org>2017-04-13 20:08:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-04-13 20:08:33 -0700
commita232591ba289a1a397e0005c9f276a126c1bc1b1 (patch)
tree78fb774d4ca742c4be1dc15f528d40598efb1393
parentd8a6e3aed955342dd68dd72e0feaf2cd32be683b (diff)
parent5714320d316ae6e830bfc463bfdaf288695f6b62 (diff)
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton: "11 fixes. The presence of 'thp: reduce indentation level in change_huge_pmd()' is unfortunate. But the patchset had been decently reviewed and tested before we decided it was needed in -stable and I felt it best not to churn things at the last minute" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mailmap: add Martin Kepplinger's email zsmalloc: expand class bit zram: do not use copy_page with non-page aligned address zram: fix operator precedence to get offset hugetlbfs: fix offset overflow in hugetlbfs mmap thp: fix MADV_DONTNEED vs clear soft dirty race thp: fix MADV_DONTNEED vs. MADV_FREE race mm: drop unused pmdp_huge_get_and_clear_notify() thp: fix MADV_DONTNEED vs. numa balancing race thp: reduce indentation level in change_huge_pmd() z3fold: fix page locking in z3fold_alloc()
-rw-r--r--.mailmap2
-rw-r--r--drivers/block/zram/zram_drv.c6
-rw-r--r--fs/hugetlbfs/inode.c15
-rw-r--r--fs/proc/task_mmu.c9
-rw-r--r--include/linux/mmu_notifier.h13
-rw-r--r--mm/huge_memory.c87
-rw-r--r--mm/z3fold.c9
-rw-r--r--mm/zsmalloc.c2
8 files changed, 92 insertions, 51 deletions
diff --git a/.mailmap b/.mailmap
index e229922dc7f0..1d6f4e7280dc 100644
--- a/.mailmap
+++ b/.mailmap
@@ -99,6 +99,8 @@ Linas Vepstas <linas@austin.ibm.com>
Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@web.de>
Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@ascom.ch>
Mark Brown <broonie@sirena.org.uk>
+Martin Kepplinger <martink@posteo.de> <martin.kepplinger@theobroma-systems.com>
+Martin Kepplinger <martink@posteo.de> <martin.kepplinger@ginzinger.com>
Matthieu CASTET <castet.matthieu@free.fr>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@brturbo.com.br>
Mauro Carvalho Chehab <mchehab@kernel.org> <maurochehab@gmail.com>
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index dceb5edd1e54..0c09d4256108 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -523,7 +523,7 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
if (size == PAGE_SIZE) {
- copy_page(mem, cmem);
+ memcpy(mem, cmem, PAGE_SIZE);
} else {
struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp);
@@ -717,7 +717,7 @@ compress_again:
if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) {
src = kmap_atomic(page);
- copy_page(cmem, src);
+ memcpy(cmem, src, PAGE_SIZE);
kunmap_atomic(src);
} else {
memcpy(cmem, src, clen);
@@ -928,7 +928,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
}
index = sector >> SECTORS_PER_PAGE_SHIFT;
- offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
+ offset = (sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
bv.bv_page = page;
bv.bv_len = PAGE_SIZE;
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 7163fe014b57..dde861387a40 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -136,17 +136,26 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
vma->vm_ops = &hugetlb_vm_ops;
+ /*
+ * Offset passed to mmap (before page shift) could have been
+ * negative when represented as a (l)off_t.
+ */
+ if (((loff_t)vma->vm_pgoff << PAGE_SHIFT) < 0)
+ return -EINVAL;
+
if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
return -EINVAL;
vma_len = (loff_t)(vma->vm_end - vma->vm_start);
+ len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+ /* check for overflow */
+ if (len < vma_len)
+ return -EINVAL;
inode_lock(inode);
file_accessed(file);
ret = -ENOMEM;
- len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
-
if (hugetlb_reserve_pages(inode,
vma->vm_pgoff >> huge_page_order(h),
len >> huge_page_shift(h), vma,
@@ -155,7 +164,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
ret = 0;
if (vma->vm_flags & VM_WRITE && inode->i_size < len)
- inode->i_size = len;
+ i_size_write(inode, len);
out:
inode_unlock(inode);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f08bd31c1081..312578089544 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -900,7 +900,14 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
- pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
+ pmd_t pmd = *pmdp;
+
+ /* See comment in change_huge_pmd() */
+ pmdp_invalidate(vma, addr, pmdp);
+ if (pmd_dirty(*pmdp))
+ pmd = pmd_mkdirty(pmd);
+ if (pmd_young(*pmdp))
+ pmd = pmd_mkyoung(pmd);
pmd = pmd_wrprotect(pmd);
pmd = pmd_clear_soft_dirty(pmd);
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 51891fb0d3ce..c91b3bcd158f 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -394,18 +394,6 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
___pud; \
})
-#define pmdp_huge_get_and_clear_notify(__mm, __haddr, __pmd) \
-({ \
- unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \
- pmd_t ___pmd; \
- \
- ___pmd = pmdp_huge_get_and_clear(__mm, __haddr, __pmd); \
- mmu_notifier_invalidate_range(__mm, ___haddr, \
- ___haddr + HPAGE_PMD_SIZE); \
- \
- ___pmd; \
-})
-
/*
* set_pte_at_notify() sets the pte _after_ running the notifier.
* This is safe to start by updating the secondary MMUs, because the primary MMU
@@ -489,7 +477,6 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
#define ptep_clear_flush_notify ptep_clear_flush
#define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
#define pudp_huge_clear_flush_notify pudp_huge_clear_flush
-#define pmdp_huge_get_and_clear_notify pmdp_huge_get_and_clear
#define set_pte_at_notify set_pte_at
#endif /* CONFIG_MMU_NOTIFIER */
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fef4cf210cc7..f3c4f9d22821 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1568,8 +1568,7 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
deactivate_page(page);
if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) {
- orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
- tlb->fullmm);
+ pmdp_invalidate(vma, addr, pmd);
orig_pmd = pmd_mkold(orig_pmd);
orig_pmd = pmd_mkclean(orig_pmd);
@@ -1724,37 +1723,69 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
{
struct mm_struct *mm = vma->vm_mm;
spinlock_t *ptl;
- int ret = 0;
+ pmd_t entry;
+ bool preserve_write;
+ int ret;
ptl = __pmd_trans_huge_lock(pmd, vma);
- if (ptl) {
- pmd_t entry;
- bool preserve_write = prot_numa && pmd_write(*pmd);
- ret = 1;
+ if (!ptl)
+ return 0;
- /*
- * Avoid trapping faults against the zero page. The read-only
- * data is likely to be read-cached on the local CPU and
- * local/remote hits to the zero page are not interesting.
- */
- if (prot_numa && is_huge_zero_pmd(*pmd)) {
- spin_unlock(ptl);
- return ret;
- }
+ preserve_write = prot_numa && pmd_write(*pmd);
+ ret = 1;
- if (!prot_numa || !pmd_protnone(*pmd)) {
- entry = pmdp_huge_get_and_clear_notify(mm, addr, pmd);
- entry = pmd_modify(entry, newprot);
- if (preserve_write)
- entry = pmd_mk_savedwrite(entry);
- ret = HPAGE_PMD_NR;
- set_pmd_at(mm, addr, pmd, entry);
- BUG_ON(vma_is_anonymous(vma) && !preserve_write &&
- pmd_write(entry));
- }
- spin_unlock(ptl);
- }
+ /*
+ * Avoid trapping faults against the zero page. The read-only
+ * data is likely to be read-cached on the local CPU and
+ * local/remote hits to the zero page are not interesting.
+ */
+ if (prot_numa && is_huge_zero_pmd(*pmd))
+ goto unlock;
+
+ if (prot_numa && pmd_protnone(*pmd))
+ goto unlock;
+
+ /*
+ * In case prot_numa, we are under down_read(mmap_sem). It's critical
+ * to not clear pmd intermittently to avoid race with MADV_DONTNEED
+ * which is also under down_read(mmap_sem):
+ *
+ * CPU0: CPU1:
+ * change_huge_pmd(prot_numa=1)
+ * pmdp_huge_get_and_clear_notify()
+ * madvise_dontneed()
+ * zap_pmd_range()
+ * pmd_trans_huge(*pmd) == 0 (without ptl)
+ * // skip the pmd
+ * set_pmd_at();
+ * // pmd is re-established
+ *
+ * The race makes MADV_DONTNEED miss the huge pmd and don't clear it
+ * which may break userspace.
+ *
+ * pmdp_invalidate() is required to make sure we don't miss
+ * dirty/young flags set by hardware.
+ */
+ entry = *pmd;
+ pmdp_invalidate(vma, addr, pmd);
+
+ /*
+ * Recover dirty/young flags. It relies on pmdp_invalidate to not
+ * corrupt them.
+ */
+ if (pmd_dirty(*pmd))
+ entry = pmd_mkdirty(entry);
+ if (pmd_young(*pmd))
+ entry = pmd_mkyoung(entry);
+ entry = pmd_modify(entry, newprot);
+ if (preserve_write)
+ entry = pmd_mk_savedwrite(entry);
+ ret = HPAGE_PMD_NR;
+ set_pmd_at(mm, addr, pmd, entry);
+ BUG_ON(vma_is_anonymous(vma) && !preserve_write && pmd_write(entry));
+unlock:
+ spin_unlock(ptl);
return ret;
}
diff --git a/mm/z3fold.c b/mm/z3fold.c
index f9492bccfd79..54f63c4a809a 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -185,6 +185,12 @@ static inline void z3fold_page_lock(struct z3fold_header *zhdr)
spin_lock(&zhdr->page_lock);
}
+/* Try to lock a z3fold page */
+static inline int z3fold_page_trylock(struct z3fold_header *zhdr)
+{
+ return spin_trylock(&zhdr->page_lock);
+}
+
/* Unlock a z3fold page */
static inline void z3fold_page_unlock(struct z3fold_header *zhdr)
{
@@ -385,7 +391,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
spin_lock(&pool->lock);
zhdr = list_first_entry_or_null(&pool->unbuddied[i],
struct z3fold_header, buddy);
- if (!zhdr) {
+ if (!zhdr || !z3fold_page_trylock(zhdr)) {
spin_unlock(&pool->lock);
continue;
}
@@ -394,7 +400,6 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
spin_unlock(&pool->lock);
page = virt_to_page(zhdr);
- z3fold_page_lock(zhdr);
if (zhdr->first_chunks == 0) {
if (zhdr->middle_chunks != 0 &&
chunks >= zhdr->start_middle)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b7ee9c34dbd6..d41edd28298b 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -276,7 +276,7 @@ struct zs_pool {
struct zspage {
struct {
unsigned int fullness:FULLNESS_BITS;
- unsigned int class:CLASS_BITS;
+ unsigned int class:CLASS_BITS + 1;
unsigned int isolated:ISOLATED_BITS;
unsigned int magic:MAGIC_VAL_BITS;
};