[PATCH 0/2] arm64: fix crash when reading /proc/kcore

Jiri Olsa jolsa at redhat.com
Tue Jun 13 07:06:20 PDT 2017


On Tue, Jun 13, 2017 at 09:17:49AM +0200, Ard Biesheuvel wrote:
> On 13 June 2017 at 04:00, Tan Xiaojun <tanxiaojun at huawei.com> wrote:
> > On 2017/6/9 3:41, Ard Biesheuvel wrote:
> >> This is a follow-up to patches from zhonjiang [0] and myself [1] that aim
> >> to solve a problem in the kcore code, which gets confused by the presence
> >> of block mappings in the vmalloc region.
> >>
> >> While fixing the crash is quite straight forward [2], we need to tweak
> >> the kcore code itself to ensure that it operates correctly on arm64.
> >> Fortunately, we can achieve this with two very simple changes:
> >>
> >> - replace a call to is_vmalloc_or_module_addr() in read_kcore() with a
> >>   comparison of the kclist type field (#1)
> >> - enable CONFIG_ARCH_PROC_KCORE_TEXT for arm64 (#2)
> >>
> >> [0] http://marc.info/?l=linux-mm&m=149632393629295&w=2
> >> [1] http://marc.info/?l=linux-mm&m=149685966530180&w=2
> >> [2] http://marc.info/?l=linux-mm&m=149694975123959&w=2
> >>
> >> Ard Biesheuvel (2):
> >>   fs/proc: kcore: use kcore_list type to check for vmalloc/module
> >>     address
> >>   arm64: mm: select CONFIG_ARCH_PROC_KCORE_TEXT
> >>
> >>  arch/arm64/Kconfig | 3 +++
> >>  fs/proc/kcore.c    | 2 +-
> >>  2 files changed, 4 insertions(+), 1 deletion(-)
> >>
> >
> > Reported-by: Tan Xiaojun <tanxiaojun at huawei.com>
> > Tested-by: Tan Xiaojun <tanxiaojun at huawei.com>
> >
> > Thank you for working on this problem which I reported two months ago.
> >
> > https://patchwork.kernel.org/patch/9687319/
> >
> > I tested, and it really solved the problem in Hisilicon D02/D03/D05.
> >
> 
> Thank you.
> 
> fs/proc/kcore.c does not have a maintainer according to
> get_maintainer.pl but it would be nice if we could get an ack on patch
> #1 from someone who is not a usual ARM suspect.
> 
> Patch #1 is here:
> http://marc.info/?l=linux-kernel&m=149695092424288&w=2
> 
> Ingo, Andrew, Jiri, any objections?

hi,
pretty straightforward.. looks ok to me

Reviewed-by: Jiri Olsa <jolsa at kernel.org>

jirka



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