diff options
| author | Chen, Kenneth W <kenneth.w.chen@intel.com> | 2006-10-11 01:20:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-11 11:14:15 -0700 |
| commit | 502717f4e112b18d9c37753a32f675bec9f2838b (patch) | |
| tree | 90e674229bbd7caa05e740dfe719cf8749d0eb27 | |
| parent | 97c7801cd5b0bb6a38c16108a496235474dc6310 (diff) | |
[PATCH] hugetlb: fix linked list corruption in unmap_hugepage_range()
commit fe1668ae5bf0145014c71797febd9ad5670d5d05 causes kernel to oops with
libhugetlbfs test suite. The problem is that hugetlb pages can be shared
by multiple mappings. Multiple threads can fight over page->lru in the
unmap path and bad things happen. We now serialize __unmap_hugepage_range
to void concurrent linked list manipulation. Such serialization is also
needed for shared page table page on hugetlb area. This patch will fixed
the bug and also serve as a prepatch for shared page table.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/hugetlbfs/inode.c | 2 | ||||
| -rw-r--r-- | include/linux/hugetlb.h | 1 | ||||
| -rw-r--r-- | mm/hugetlb.c | 22 |
3 files changed, 22 insertions, 3 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 5e03b2f67b93..4ee3f006b861 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -293,7 +293,7 @@ hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) if (h_vm_pgoff >= h_pgoff) v_offset = 0; - unmap_hugepage_range(vma, + __unmap_hugepage_range(vma, vma->vm_start + v_offset, vma->vm_end); } } diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index c25a38d8f600..5081d27bfa27 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -17,6 +17,7 @@ int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user * int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *); int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int); void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long); +void __unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long); int hugetlb_prefault(struct address_space *, struct vm_area_struct *); int hugetlb_report_meminfo(char *); int hugetlb_report_node_meminfo(int, char *); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1d709ff528e1..2dbec90dc3ba 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -356,8 +356,8 @@ nomem: return -ENOMEM; } -void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, - unsigned long end) +void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) { struct mm_struct *mm = vma->vm_mm; unsigned long address; @@ -398,6 +398,24 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, } } +void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + /* + * It is undesirable to test vma->vm_file as it should be non-null + * for valid hugetlb area. However, vm_file will be NULL in the error + * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, + * do_mmap_pgoff() nullifies vma->vm_file before calling this function + * to clean up. Since no pte has actually been setup, it is safe to + * do nothing in this case. + */ + if (vma->vm_file) { + spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); + __unmap_hugepage_range(vma, start, end); + spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); + } +} + static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t pte) { |