Messages in this thread | | | Date | Sat, 15 Nov 2008 20:15:15 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH] Fix kunmap() argument in sg_miter_stop |
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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().
I'd expect what you're fixing to manifest as an mm/highmem.c:207 - the BUG_ON(!vaddr) in kunmap_high(). Or have I just got in a terrible muddle?
Of course, I'd love it to explain mm/highmem.c:319, but I can't see that either.
Hugh
> > This is moderately popular on kerneloops.org, mostly in interaction with the MMC layer. > > Reported-by: kerneloops.org > CC: htejun@gmail.com > CC: stable@kernel.org > > 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
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