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| author | Paul Mundt <lethal@linux-sh.org> | 2009-01-08 12:04:48 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2009-01-08 12:04:48 +0000 |
| commit | ab2e83ead4eca9e045daac4cbf66eb1e7a244bb2 (patch) | |
| tree | 0e42c62476d09a5b7389ba02eb093448af36c58b /mm/nommu.c | |
| parent | 0f3e442a403a344a5d0a49af9ecd7632b7e7343a (diff) | |
| download | lwn-ab2e83ead4eca9e045daac4cbf66eb1e7a244bb2.tar.gz lwn-ab2e83ead4eca9e045daac4cbf66eb1e7a244bb2.zip | |
NOMMU: Teach kobjsize() about VMA regions.
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>
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index a6e8ccfbd400..60ed8375c986 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. */ |