Suzuki K Poulose d755209f6a coresight: etm_perf: Fix using uninitialised work
With 4.11-rc4, the following command triggers a WARN_ON,
when a sink is not enabled.

 perf record -e cs_etm/@20010000.etf/

 [88286.547741] ------------[ cut here ]------------
 [88286.552332] WARNING: CPU: 3 PID: 2156 at kernel/workqueue.c:1442 __queue_work+0x29c/0x3b8
 [88286.560427] Modules linked in:
 [88286.563451]
 [88286.564928] CPU: 3 PID: 2156 Comm: perf_v4.11 Not tainted 4.11.0-rc4 #217
 [88286.573453] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Aug 15
  2016
 [88286.584128] task: ffff80097597c200 task.stack: ffff8009768b0000
 [88286.589990] PC is at __queue_work+0x29c/0x3b8
 [88286.594303] LR is at __queue_work+0x104/0x3b8
 [88286.598614] pc : [<ffff0000080d8c7c>] lr : [<ffff0000080d8ae4>] pstate: a00001c5
 [88286.605934] sp : ffff8009768b3aa0
 [88286.609212] x29: ffff8009768b3aa0 x28: ffff80097ff3da00
 [88286.614477] x27: ffff80097ff89c00 x26: ffff8009751b0e00
 [88286.619741] x25: ffff000008c9f000 x24: 0000000000000003
 [88286.625004] x23: 0000000000000040 x22: ffff000008d3dab8
 [88286.630268] x21: ffff800977804400 x20: 0000000000000007
 [88286.635532] x19: ffff000008c54000 x18: 0000fffff9185160
 [88286.640795] x17: 0000ffffb33d9a38 x16: ffff000008088270
 [88286.646059] x15: 0000ffffb345b590 x14: 0000000000000000
 [88286.651322] x13: 0000000000000004 x12: 0000000000000040
 [88286.656586] x11: 0000000000000068 x10: 0000000000000000
 [88286.661849] x9 : ffff800977400028 x8 : 0000000000000000
 [88286.667113] x7 : 0000000000000000 x6 : ffff0000080d8ae4
 [88286.672376] x5 : 0000000000000000 x4 : 0000000000000080
 [88286.677639] x3 : 0000000000000000 x2 : 0000000000000000
 [88286.682903] x1 : 0000000000000000 x0 : ffff8009751b0e08
 [88286.688166]
 [88286.689638] ---[ end trace 31633f18fd33d4cb ]---
 [88286.694206] Call trace:
 [88286.696627] Exception stack(0xffff8009768b38d0 to 0xffff8009768b3a00)
 [88286.703004] 38c0:                                   ffff000008c54000 0001000000000000
 [88286.710757] 38e0: ffff8009768b3aa0 ffff0000080d8c7c ffff8009768b3b50 ffff80097ff8a5b0
 [88286.718511] 3900: 0000800977325000 0000000000000000 0000000000000040 ffff80097ffc6180
 [88286.726264] 3920: ffff8009768b3940 ffff0000088a8694 ffff80097ffc5800 0000000000000000
 [88286.734017] 3940: ffff8009768b3960 ffff0000081919c0 ffff80097ffc5280 0000000000000001
 [88286.741771] 3960: ffff8009768b3a50 ffff00000819206c ffff8009751b0e08 0000000000000000
 [88286.749523] 3980: 0000000000000000 0000000000000000 0000000000000080 0000000000000000
 [88286.757277] 39a0: ffff0000080d8ae4 0000000000000000 0000000000000000 ffff800977400028
 [88286.765029] 39c0: 0000000000000000 0000000000000068 0000000000000040 0000000000000004
 [88286.772783] 39e0: 0000000000000000 0000ffffb345b590 ffff000008088270 0000ffffb33d9a38
 [88286.780537] [<ffff0000080d8c7c>] __queue_work+0x29c/0x3b8
 [88286.785883] [<ffff0000080d8df8>] queue_work_on+0x60/0x78
 [88286.791146] [<ffff000008764c68>] etm_setup_aux+0x178/0x238
 [88286.796578] [<ffff000008183600>] rb_alloc_aux+0x228/0x310
 [88286.801925] [<ffff00000817e564>] perf_mmap+0x404/0x5a8
 [88286.807015] [<ffff0000081c60cc>] mmap_region+0x394/0x5c0
 [88286.812276] [<ffff0000081c654c>] do_mmap+0x254/0x388
 [88286.817191] [<ffff0000081a989c>] vm_mmap_pgoff+0xbc/0xe0
 [88286.822452] [<ffff0000081c3ffc>] SyS_mmap_pgoff+0xac/0x228
 [88286.827884] [<ffff000008088288>] sys_mmap+0x18/0x28
 [88286.832714] [<ffff000008082f30>] el0_svc_naked+0x24/0x28

The patch makes sure that the event_data->work is initialised
properly before we could possibly use it.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:45:24 +02:00
2017-05-08 17:15:12 -07:00
2017-05-22 08:56:55 +02:00
2017-05-21 19:30:23 -07:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.6 GiB
Languages
C 97.1%
Assembly 1%
Shell 0.6%
Rust 0.4%
Python 0.4%
Other 0.3%