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From: William Cohen <wcohen@redhat.com>
To: Pratyush Anand <panand@redhat.com>
Cc: David Long <dave.long@linaro.org>,
	systemtap@sourceware.org,        Mark Brown <broonie@linaro.org>,
	Jeremy Linton <jlinton@redhat.com>,
	       David Smith <dsmith@redhat.com>,
	"Frank Ch. Eigler" <fche@redhat.com>
Subject: Re: exercising current aarch64 kprobe support with systemtap
Date: Thu, 04 Aug 2016 20:51:00 -0000	[thread overview]
Message-ID: <fd49a38c-a429-545f-be76-b63faf92c084@redhat.com> (raw)
In-Reply-To: <20160804143549.GF22191@localhost.localdomain>

On 08/04/2016 10:35 AM, Pratyush Anand wrote:
> Hi Will,
> 
> On 04/08/2016:09:56:45 AM, William Cohen wrote:
...
>> Hi,
>>
>> The OOM errors came before the otf_stress_hard_iter_5000 test that previous triggered the infinite unexpected EL1, so can't really say that the proposed patch has fixed the problem.
> 
> Yes, yes, previously also we were getting OOM, and then that OOM was triggering
> infinite unexpected EL1, because OOM message uses WARN_ON() to print, and
> WARN_ON() uses "BRK BUG_BRK_IMM". Now when it is printing though BRK, we were
> hitting kprobe at print_worker_info() which was resulting in unexpected EL1.
> 
> Proposed patch fixes kprobe tracing within none kprobe BRK context such as
> uprobe or WARN_ON() breakpoint handler etc. So, now a kprobe at
> print_worker_info() will work while printing message of WARN_ON().
> 
> 
>>
>> Any thoughts on how to track down the oom issue?  Are you able to replicate it running the systemtap onthefly/kprobes_onthefly.exp tests?
> 
> Sure, will look into. Have reserved a seattle.
> 
> ~Pratyush
> 

Hi Pratyush,

The stack backtrace of http://paste.stg.fedoraproject.org/5375/ is:


[  668.676682] [<fffffc00082386fc>] page_counter_cancel+0x54/0x60
[  668.682508] [<fffffc000823885c>] page_counter_uncharge+0x2c/0x40
[  668.688509] [<fffffc0008239c68>] cancel_charge+0x40/0xe0
[  668.693815] [<fffffc000823fdfc>] mem_cgroup_cancel_charge+0x2c/0x38
[  668.700088] [<fffffc00081c96a8>] uprobe_write_opcode+0x4e8/0x688
[  668.706089] [<fffffc00081c9878>] set_swbp+0x30/0x40
[  668.710962] [<fffffc00081c98e4>] install_breakpoint.isra.10+0x5c/0x2b8
[  668.717484] [<fffffc00081ca6d8>] uprobe_mmap+0x248/0x2a8
[  668.722791] [<fffffc000820fbac>] mmap_region+0x204/0x558
[  668.728097] [<fffffc0008210164>] do_mmap+0x264/0x320
[  668.733057] [<fffffc00081f2238>] vm_mmap_pgoff+0xb0/0xd8
[  668.738363] [<fffffc00081f22d0>] vm_mmap+0x70/0xa0
[  668.743149] [<fffffc00082a62c8>] elf_map+0x80/0xf8
[  668.747934] [<fffffc00082a7a48>] load_elf_binary+0x480/0xb90
[  668.753588] [<fffffc0008252e7c>] search_binary_handler+0xbc/0x210
[  668.759674] [<fffffc0008253810>] do_execveat_common+0x4b0/0x620
[  668.765587] [<fffffc0008253c74>] SyS_execve+0x44/0x58
[  668.770633] [<fffffc0008082c4c>] __sys_trace_return+0x0/0x4

There is some uprobe code running in the traceback.  It looks like things are going wrong when uprobes are being installed on a newly loaded executable.

-Will

  parent reply	other threads:[~2016-08-04 20:51 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-09 16:17 William Cohen
2016-06-09 19:52 ` William Cohen
2016-06-10  3:42   ` David Long
2016-06-10  5:49   ` David Long
2016-06-10 13:43     ` Pratyush Anand
2016-06-10 14:03       ` William Cohen
2016-06-10 14:37         ` David Long
2016-06-10 15:27           ` William Cohen
2016-06-10 14:20       ` David Long
2016-06-10 15:11         ` William Cohen
2016-06-10 17:07         ` Pratyush Anand
2016-07-12 14:33     ` William Cohen
2016-07-13 18:26       ` David Long
2016-07-13 18:47         ` Pratyush Anand
2016-07-13 19:45           ` William Cohen
2016-06-10 21:28 ` William Cohen
2016-06-10 21:37   ` William Cohen
2016-06-13  4:28   ` Pratyush Anand
2016-06-13 13:42     ` William Cohen
2016-06-22 20:24   ` William Cohen
2016-06-23  3:19     ` David Long
2016-06-23 13:42       ` William Cohen
2016-06-23 13:47         ` David Smith
2016-06-23 15:49       ` William Cohen
2016-06-23 18:26         ` David Long
2016-06-23 19:22           ` William Cohen
2016-06-27  2:57             ` David Long
2016-06-27 14:18             ` Pratyush Anand
2016-06-28  3:20               ` William Cohen
2016-07-04 12:46                 ` Pratyush Anand
2016-07-07 19:05                   ` David Long
2016-07-07 19:58                     ` Frank Ch. Eigler
2016-08-03 13:13                       ` Pratyush Anand
2016-08-03 14:51                         ` William Cohen
2016-08-03 15:11                           ` David Long
2016-08-03 17:40                         ` William Cohen
2016-08-03 20:00                           ` Lastest kprobes64 patch David Long
2016-08-03 20:01                             ` Frank Ch. Eigler
2016-08-03 20:08                               ` David Long
2016-08-04  5:03                             ` Pratyush Anand
2016-08-04 13:07                               ` David Long
2016-08-04  4:42                           ` exercising current aarch64 kprobe support with systemtap Pratyush Anand
2016-08-04 13:57                             ` William Cohen
2016-08-04 14:36                               ` Pratyush Anand
2016-08-04 14:50                                 ` William Cohen
2016-08-04 20:51                                 ` William Cohen [this message]
2016-08-17 14:36                                   ` William Cohen
2016-08-17 18:04                                     ` David Smith
2016-08-17 18:28                                       ` William Cohen
2016-08-18 15:07                                         ` David Smith
2016-08-18 15:16                                           ` William Cohen
2016-08-18 15:39                                             ` David Smith
2016-08-18 14:55                                     ` Pratyush Anand
2016-06-13 16:11 ` William Cohen
2016-06-13 16:15   ` William Cohen
2016-06-14  4:27   ` Pratyush Anand

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