[PATCH] msync: fix return value
msync() does a strange thing. Essentially: vma = find_vma(); for ( ; ; ) { if (!vma) return -ENOMEM; ... vma = vma->vm_next; } so an msync() request which starts within or before a valid VMA and which ends within or beyond the final VMA will incorrectly return -ENOMEM. Fix. Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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parent
707c21c848
commit
676758bdb7
14
mm/msync.c
14
mm/msync.c
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@ -146,7 +146,8 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
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{
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unsigned long end;
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struct vm_area_struct *vma;
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int unmapped_error, error = -EINVAL;
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int unmapped_error = 0;
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int error = -EINVAL;
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int done = 0;
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if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
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@ -171,15 +172,14 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
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if (flags & MS_SYNC)
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current->flags |= PF_SYNCWRITE;
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vma = find_vma(current->mm, start);
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unmapped_error = 0;
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if (!vma) {
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error = -ENOMEM;
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goto out_unlock;
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}
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do {
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unsigned long nr_pages_dirtied = 0;
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struct file *file;
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/* Still start < end. */
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error = -ENOMEM;
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if (!vma)
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goto out_unlock;
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/* Here start < vma->vm_end. */
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if (start < vma->vm_start) {
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unmapped_error = -ENOMEM;
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@ -239,7 +239,7 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
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} else {
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vma = vma->vm_next;
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}
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} while (!done);
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} while (vma && !done);
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out_unlock:
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current->flags &= ~PF_SYNCWRITE;
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up_read(¤t->mm->mmap_sem);
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