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

[Ard Biesheuvel]

On 13 June 2017 at 04:00, Tan Xiaojun <tanxiaojun@xxxxxxxxxx> 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@xxxxxxxxxx>
> Tested-by: Tan Xiaojun <tanxiaojun@xxxxxxxxxx>
>
> 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?