ksm: mremap use err from ksm_madvise (7103ad32) · Commits · 戴 / test

mremap move's use of ksm_madvise() was assuming -ENOMEM on failure, because ksm_madvise used to say -EAGAIN for that; but ksm_madvise now says -ENOMEM (letting madvise convert that to -EAGAIN), and can also say -ERESTARTSYS when signalled: so pass the error from ksm_madvise. Signed-off-by:

Hugh Dickins <hugh.dickins@tiscali.co.uk> Acked-by:

Izik Eidus <ieidus@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/mremap.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -175,6 +175,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
		unsigned long excess = 0;
		unsigned long hiwater_vm;
		int split = 0;
		int err;

		/*
		* We'd prefer to avoid failure later on in do_munmap:
		@@ -190,9 +191,10 @@ static unsigned long move_vma(struct vm_area_struct *vma,
		* pages recently unmapped. But leave vma->vm_flags as it was,
		* so KSM can come around to merge on vma and new_vma afterwards.
		*/
		if (ksm_madvise(vma, old_addr, old_addr + old_len,
		MADV_UNMERGEABLE, &vm_flags))
		return -ENOMEM;
		err = ksm_madvise(vma, old_addr, old_addr + old_len,
		MADV_UNMERGEABLE, &vm_flags);
		if (err)
		return err;

		new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
		new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);

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