Messages in this thread Patch in this message | | | From | David Howells <> | Subject | [PATCH 09/10] NOMMU: Teach kobjsize() about VMA regions. [ver #3] | Date | Thu, 08 Jan 2009 12:54:32 +0000 |
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From: Paul Mundt <lethal@linux-sh.org>
Now that we no longer use compound pages for all large allocations, kobjsize() actively breaks things like binfmt_flat by always handing back PAGE_SIZE for mmap'ed regions. Fix this up by looking up the VMA region for non-compounds.
Ideally binfmt_flat wants to get rid of kobjsize() completely, but this is an incremental step.
Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Mike Frysinger <vapier.adi@gmail.com> ---
mm/nommu.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c index a6e8ccf..60ed837 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -149,6 +149,20 @@ unsigned int kobjsize(const void *objp) return ksize(objp); /* + * If it's not a compound page, see if we have a matching VMA + * region. This test is intentionally done in reverse order, + * so if there's no VMA, we still fall through and hand back + * PAGE_SIZE for 0-order pages. + */ + if (!PageCompound(page)) { + struct vm_area_struct *vma; + + vma = find_vma(current->mm, (unsigned long)objp); + if (vma) + return vma->vm_end - vma->vm_start; + } + + /* * The ksize() function is only guaranteed to work for pointers * returned by kmalloc(). So handle arbitrary pointers here. */
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