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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 22:11:15 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 22:11:15 +0100
commitf6e858a00af788bab0fd4c0b7f5cd788000edc18 (patch)
treef9403ca3671be9821dbf83e726e61dbe75fbca6b /mm/mmap.c
parentMerge tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci (diff)
parentmm/bootmem.c: remove unused wrapper function reserve_bootmem_generic() (diff)
downloadlinux-f6e858a00af788bab0fd4c0b7f5cd788000edc18.tar.xz
linux-f6e858a00af788bab0fd4c0b7f5cd788000edc18.zip
Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc VM changes from Andrew Morton: "The rest of most-of-MM. The other MM bits await a slab merge. This patch includes the addition of a huge zero_page. Not a performance boost but it an save large amounts of physical memory in some situations. Also a bunch of Fujitsu engineers are working on memory hotplug. Which, as it turns out, was badly broken. About half of their patches are included here; the remainder are 3.8 material." However, this merge disables CONFIG_MOVABLE_NODE, which was totally broken. We don't add new features with "default y", nor do we add Kconfig questions that are incomprehensible to most people without any help text. Does the feature even make sense without compaction or memory hotplug? * akpm: (54 commits) mm/bootmem.c: remove unused wrapper function reserve_bootmem_generic() mm/memory.c: remove unused code from do_wp_page() asm-generic, mm: pgtable: consolidate zero page helpers mm/hugetlb.c: fix warning on freeing hwpoisoned hugepage hwpoison, hugetlbfs: fix RSS-counter warning hwpoison, hugetlbfs: fix "bad pmd" warning in unmapping hwpoisoned hugepage mm: protect against concurrent vma expansion memcg: do not check for mm in __mem_cgroup_count_vm_event tmpfs: support SEEK_DATA and SEEK_HOLE (reprise) mm: provide more accurate estimation of pages occupied by memmap fs/buffer.c: remove redundant initialization in alloc_page_buffers() fs/buffer.c: do not inline exported function writeback: fix a typo in comment mm: introduce new field "managed_pages" to struct zone mm, oom: remove statically defined arch functions of same name mm, oom: remove redundant sleep in pagefault oom handler mm, oom: cleanup pagefault oom handler memory_hotplug: allow online/offline memory to result movable node numa: add CONFIG_MOVABLE_NODE for movable-dedicated node mm, memcg: avoid unnecessary function call when memcg is disabled ...
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index f940062c8d4b..2b7d9e78a569 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1488,7 +1488,11 @@ munmap_back:
*
* Answer: Yes, several device drivers can do it in their
* f_op->mmap method. -DaveM
+ * Bug: If addr is changed, prev, rb_link, rb_parent should
+ * be updated for vma_link()
*/
+ WARN_ON_ONCE(addr != vma->vm_start);
+
addr = vma->vm_start;
pgoff = vma->vm_pgoff;
vm_flags = vma->vm_flags;
@@ -2065,6 +2069,18 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) {
error = acct_stack_growth(vma, size, grow);
if (!error) {
+ /*
+ * vma_gap_update() doesn't support concurrent
+ * updates, but we only hold a shared mmap_sem
+ * lock here, so we need to protect against
+ * concurrent vma expansions.
+ * vma_lock_anon_vma() doesn't help here, as
+ * we don't guarantee that all growable vmas
+ * in a mm share the same root anon vma.
+ * So, we reuse mm->page_table_lock to guard
+ * against concurrent vma expansions.
+ */
+ spin_lock(&vma->vm_mm->page_table_lock);
anon_vma_interval_tree_pre_update_vma(vma);
vma->vm_end = address;
anon_vma_interval_tree_post_update_vma(vma);
@@ -2072,6 +2088,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
vma_gap_update(vma->vm_next);
else
vma->vm_mm->highest_vm_end = address;
+ spin_unlock(&vma->vm_mm->page_table_lock);
+
perf_event_mmap(vma);
}
}
@@ -2122,11 +2140,25 @@ int expand_downwards(struct vm_area_struct *vma,
if (grow <= vma->vm_pgoff) {
error = acct_stack_growth(vma, size, grow);
if (!error) {
+ /*
+ * vma_gap_update() doesn't support concurrent
+ * updates, but we only hold a shared mmap_sem
+ * lock here, so we need to protect against
+ * concurrent vma expansions.
+ * vma_lock_anon_vma() doesn't help here, as
+ * we don't guarantee that all growable vmas
+ * in a mm share the same root anon vma.
+ * So, we reuse mm->page_table_lock to guard
+ * against concurrent vma expansions.
+ */
+ spin_lock(&vma->vm_mm->page_table_lock);
anon_vma_interval_tree_pre_update_vma(vma);
vma->vm_start = address;
vma->vm_pgoff -= grow;
anon_vma_interval_tree_post_update_vma(vma);
vma_gap_update(vma);
+ spin_unlock(&vma->vm_mm->page_table_lock);
+
perf_event_mmap(vma);
}
}