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From: Florian Weimer <fweimer@redhat.com>
To: Ram Pai <linuxram@us.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>, Linux-MM <linux-mm@kvack.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Dave Hansen <dave.hansen@intel.com>
Subject: Re: pkeys on POWER: Access rights not reset on execve
Date: Mon, 4 Jun 2018 12:12:07 +0200	[thread overview]
Message-ID: <4e53b91f-80a7-816a-3e9b-56d7be7cd092@redhat.com> (raw)
In-Reply-To: <20180603201832.GA10109@ram.oc3035372033.ibm.com>

On 06/03/2018 10:18 PM, Ram Pai wrote:
> On Mon, May 21, 2018 at 01:29:11PM +0200, Florian Weimer wrote:
>> On 05/20/2018 09:11 PM, Ram Pai wrote:
>>> Florian,
>>>
>>> 	Does the following patch fix the problem for you?  Just like x86
>>> 	I am enabling all keys in the UAMOR register during
>>> 	initialization itself. Hence any key created by any thread at
>>> 	any time, will get activated on all threads. So any thread
>>> 	can change the permission on that key. Smoke tested it
>>> 	with your test program.
>>
>> I think this goes in the right direction, but the AMR value after
>> fork is still strange:
>>
>> AMR (PID 34912): 0x0000000000000000
>> AMR after fork (PID 34913): 0x0000000000000000
>> AMR (PID 34913): 0x0000000000000000
>> Allocated key in subprocess (PID 34913): 2
>> Allocated key (PID 34912): 2
>> Setting AMR: 0xffffffffffffffff
>> New AMR value (PID 34912): 0x0fffffffffffffff
>> About to call execl (PID 34912) ...
>> AMR (PID 34912): 0x0fffffffffffffff
>> AMR after fork (PID 34914): 0x0000000000000003
>> AMR (PID 34914): 0x0000000000000003
>> Allocated key in subprocess (PID 34914): 2
>> Allocated key (PID 34912): 2
>> Setting AMR: 0xffffffffffffffff
>> New AMR value (PID 34912): 0x0fffffffffffffff
>>
>> I mean this line:
>>
>> AMR after fork (PID 34914): 0x0000000000000003
>>
>> Shouldn't it be the same as in the parent process?
> 
> Fixed it. Please try this patch. If it all works to your satisfaction, I
> will clean it up further and send to Michael Ellermen(ppc maintainer).
> 
> 
> commit 51f4208ed5baeab1edb9b0f8b68d7144449b3527
> Author: Ram Pai <linuxram@us.ibm.com>
> Date:   Sun Jun 3 14:44:32 2018 -0500
> 
>      Fix for the fork bug.
>      
>      Signed-off-by: Ram Pai <linuxram@us.ibm.com>

Is this on top of the previous patch, or a separate fix?

Thanks,
Florian

  reply	other threads:[~2018-06-04 10:12 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-18 14:27 pkeys on POWER: Access rights not reset on execve Florian Weimer
2018-05-19  1:19 ` Ram Pai
2018-05-19  1:50   ` Andy Lutomirski
2018-05-19  5:26     ` Florian Weimer
2018-05-19 20:27     ` Ram Pai
2018-05-19 23:47       ` Andy Lutomirski
2018-05-20  6:04         ` Ram Pai
2018-05-20  6:06           ` Andy Lutomirski
2018-05-20 19:11             ` Ram Pai
2018-05-21 11:29               ` Florian Weimer
2018-06-03 20:18                 ` Ram Pai
2018-06-04 10:12                   ` Florian Weimer [this message]
2018-06-04 14:01                     ` Ram Pai
2018-06-04 17:57                       ` Florian Weimer
2018-06-04 19:02                         ` Ram Pai
2018-06-04 21:00                           ` Florian Weimer
2018-06-08  2:34                             ` Ram Pai
2018-06-08  5:53                               ` Florian Weimer
2018-06-08 10:15                                 ` Michal Suchánek
2018-06-08 10:44                                   ` Florian Weimer
2018-06-08 12:54                                     ` Michal Suchánek
2018-06-08 12:57                                       ` Florian Weimer
2018-06-08 13:49                                         ` Michal Suchánek
2018-06-08 13:51                                           ` Florian Weimer
2018-06-08 14:17                                             ` Michal Suchánek
2018-06-11 17:23                                 ` Ram Pai
2018-06-11 17:29                                   ` Florian Weimer
2018-06-11 20:08                                     ` Ram Pai
2018-06-12 12:17                                       ` Florian Weimer
2018-05-19  5:12   ` Florian Weimer
2018-05-19 11:11   ` Florian Weimer

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