Messages in this thread Patch in this message | | | Date | Sat, 15 Nov 2008 12:39:16 -0800 | From | Arjan van de Ven <> | Subject | Re: [PATCH] Fix kunmap() argument in sg_miter_stop |
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On Sat, 15 Nov 2008 20:15:15 +0000 (GMT) Hugh Dickins <hugh@veritas.com> wrote:
> On Sat, 15 Nov 2008, Arjan van de Ven wrote: > > >From fd5530ac75a919a20bf7951e90a2b12323e9c0a0 Mon Sep 17 00:00:00 > > >2001 > > From: Arjan van de Ven <arjan@linux.intel.com> > > Date: Sat, 15 Nov 2008 11:23:58 -0800 > > Subject: [PATCH] Fix kunmap() argument in sg_miter_stop > > > > kunmap() takes as argument the struct page that orginally got > > kmap()'d, however the sg_miter_stop() function passed it the kernel > > virtual address instead, resulting in "kernel BUG at > > arch/x86/mm/highmem_32.c:115!" > > Your patch looks like a good fix to me, but I don't get how its bug > would manifest as highmem_32.c:115 - that's a check in > kunmap_atomic(), whereas you're fixing a bad address to kunmap().
patch with updated description:
From 979d181d6199f639ba78c5eadf85857f6a9f3f89 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven <arjan@linux.intel.com> Date: Sat, 15 Nov 2008 11:23:58 -0800 Subject: [PATCH] Fix kunmap() argument in sg_miter_stop
kunmap() takes as argument the struct page that orginally got kmap()'d, however the sg_miter_stop() function passed it the kernel virtual address instead, resulting in weird stuff.
Somehow I ended up fixing this bug by accident while looking for a bug in the same area.
Reported-by: kerneloops.org CC: htejun@gmail.com
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> --- lib/scatterlist.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 8d2688f..b7b449d 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -395,7 +395,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter) WARN_ON(!irqs_disabled()); kunmap_atomic(miter->addr, KM_BIO_SRC_IRQ); } else - kunmap(miter->addr); + kunmap(miter->page); miter->page = NULL; miter->addr = NULL; -- 1.6.0.3
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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