Messages in this thread | | | Date | Mon, 21 Jun 2010 18:56:30 +0800 | From | Xiaotian Feng <> | Subject | Re: [patch] x86, pat: freeing invalid memtype messages |
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On 06/19/2010 01:57 AM, Marcin Slusarz wrote: > On Fri, Jun 18, 2010 at 02:47:45PM +0800, Xiaotian Feng wrote: >> On 06/18/2010 12:17 AM, Marcin Slusarz wrote: >>> On Thu, Jun 17, 2010 at 03:45:59PM +0200, Dan Carpenter wrote: >>>> Commit 20413f27163 "x86, pat: Fix memory leak in free_memtype" added an >>>> error message in free_memtype() if rbt_memtype_erase() returns NULL. >>>> The problem is that if CONFIG_X86_PAT is enabled, we use a different >>>> implimentation of rbt_memtype_erase() that always returns NULL. >>>> >>>> I've modified rbt_memtype_erase() to return an ERR_PTR() on errors and >>>> made free_memtype() check for that instead. >>>> >>>> Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16205 >>>> >>>> Signed-off-by: Dan Carpenter<error27@gmail.com> >>> >>> This patch is probably ok, but it does not address my bug. >>> I have CONFIG_X86_PAT=y, so rbt_memtype_erase does not always return NULL. >> >> Could you please try boot with kernel parameter "debugpat", and >> show me the output of reserve_memtype/free_memtype ? >> >> > > > http://kadu.net/~joi/kernel/2010.06.09/2.6.35-rc3-debugpat.txt
That's quite weird, from the above log:
[ 1.787891] reserve_memtype added 0xbf799000-0xbf79a000, track uncached-minus, req uncached-minus, ret uncached-minus [ 1.791029] free_memtype request 0xbf799000-0xbf79a000 [ 1.791822] reserve_memtype added 0xbf799000-0xbf79a000, track uncached-minus, req uncached-minus, ret uncached-minus [ 1.794998] swapper:1 freeing invalid memtype bf799000-bf79a000 [ 1.795795] reserve_memtype added 0xbf799000-0xbf79a000, track uncached-minus, req uncached-minus, ret uncached-minus [ 1.798979] free_memtype request 0xbf799000-0xbf79a000 [ 1.799775] Overlap at 0xbf799000-0xbf79a000
[ 22.271353] reserve_memtype added 0xd0a40000-0xd0a50000, track write-combining, req write-combining, ret write-combining [ 22.275707] free_memtype request 0xd0a40000-0xd0a50000 [ 23.209570] reserve_memtype added 0xd0a40000-0xd0a50000, track write-combining, req write-combining, ret write-combining [ 23.213888] X:2538 freeing invalid memtype d0a40000-d0a50000 [ 23.214065] reserve_memtype added 0xd0a40000-0xd0a50000, track write-combining, req write-combining, ret write-combining [ 23.218415] free_memtype request 0xd0a40000-0xd0a50000 [ 26.028404] Overlap at 0xd0a40000-0xd0a50000
So it looks like after we free_memtype, reserve the same area again, then free_memtype again showed us the invalid memtype (was not found in rbtree). But the third time reserve_memtype found overlap (it's in rbtree)...
I guess there might be something wrong between the augmented rbtree insert/remove ..
(Cc'ed Peter)
> > Marcin >
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