Mike Leach e4b7d7297d coresight: cti: Fix null pointer error on CTI init before ETM
[ Upstream commit 3dc228b353 ]

When CTI is discovered first then the function
coresight_set_assoc_ectdev_mutex() is called to set the association
between CTI and ETM device. Recent lockdep fix passes a null pointer.

This patch passes the correct pointer.

Before patch: log of boot oops sequence with CTI discovered first:

[   12.424091]  cs_system_cfg: CoreSight Configuration manager initialised
[   12.483474] coresight cti_sys0: CTI initialized
[   12.488109] coresight cti_sys1: CTI initialized
[   12.503594] coresight cti_cpu0: CTI initialized
[   12.517877] coresight-cpu-debug 850000.debug: Coresight debug-CPU0 initialized
[   12.523479] coresight-cpu-debug 852000.debug: Coresight debug-CPU1 initialized
[   12.529926] coresight-cpu-debug 854000.debug: Coresight debug-CPU2 initialized
[   12.541808] coresight stm0: STM32 initialized
[   12.544421] coresight-cpu-debug 856000.debug: Coresight debug-CPU3 initialized
[   12.585639] coresight cti_cpu1: CTI initialized
[   12.614028] coresight cti_cpu2: CTI initialized
[   12.631679] CSCFG registered etm0
[   12.633920] coresight etm0: CPU0: etm v4.0 initialized
[   12.656392] coresight cti_cpu3: CTI initialized

...

[   12.708383] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000348

...

[   12.755094] Internal error: Oops: 0000000096000044 [#1] SMP
[   12.761817] Modules linked in: coresight_etm4x(+) coresight_tmc coresight_cpu_debug coresight_replicator coresight_funnel coresight_cti coresight_tpiu coresight_stm coresight
[   12.767210] CPU: 3 PID: 1346 Comm: systemd-udevd Not tainted 6.1.0-rc3tid-v6tid-v6-235166-gf7f7d7a2204a-dirty #498
[   12.782827] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[   12.793154] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   12.800010] pc : coresight_set_assoc_ectdev_mutex+0x30/0x50 [coresight]
[   12.806694] lr : coresight_set_assoc_ectdev_mutex+0x30/0x50 [coresight]

...

[   12.885064] Call trace:
[   12.892352]  coresight_set_assoc_ectdev_mutex+0x30/0x50 [coresight]
[   12.894693]  cti_add_assoc_to_csdev+0x144/0x1b0 [coresight_cti]
[   12.900943]  coresight_register+0x2c8/0x320 [coresight]
[   12.906844]  etm4_add_coresight_dev.isra.27+0x148/0x280 [coresight_etm4x]
[   12.912056]  etm4_probe+0x144/0x1c0 [coresight_etm4x]
[   12.918998]  etm4_probe_amba+0x40/0x78 [coresight_etm4x]
[   12.924032]  amba_probe+0x11c/0x1f0

After patch: similar log

[   12.444467]  cs_system_cfg: CoreSight Configuration manager initialised
[   12.456329] coresight-cpu-debug 850000.debug: Coresight debug-CPU0 initialized
[   12.456754] coresight-cpu-debug 852000.debug: Coresight debug-CPU1 initialized
[   12.469672] coresight-cpu-debug 854000.debug: Coresight debug-CPU2 initialized
[   12.476098] coresight-cpu-debug 856000.debug: Coresight debug-CPU3 initialized
[   12.532409] coresight stm0: STM32 initialized
[   12.533708] coresight cti_sys0: CTI initialized
[   12.539478] coresight cti_sys1: CTI initialized
[   12.550106] coresight cti_cpu0: CTI initialized
[   12.633931] coresight cti_cpu1: CTI initialized
[   12.634664] coresight cti_cpu2: CTI initialized
[   12.638090] coresight cti_cpu3: CTI initialized
[   12.721136] CSCFG registered etm0

...

[   12.762643] CSCFG registered etm1
[   12.762666] coresight etm1: CPU1: etm v4.0 initialized
[   12.776258] CSCFG registered etm2
[   12.776282] coresight etm2: CPU2: etm v4.0 initialized
[   12.784357] CSCFG registered etm3
[   12.785455] coresight etm3: CPU3: etm v4.0 initialized

Error can also be triggered by manually starting the modules using modprobe
in the following order:

root@linaro-developer:/home/linaro/cs-mods# modprobe coresight
root@linaro-developer:/home/linaro/cs-mods# modprobe coresight-cti
root@linaro-developer:/home/linaro/cs-mods# modprobe coresight-etm4x

Tested on Dragonboard DB410c
Applies to coresight/next

Fixes: 23722fb467 ("coresight: Fix possible deadlock with lock dependency")
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20221123193818.6253-1-mike.leach@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31 13:32:41 +01:00
2022-12-31 13:32:38 +01:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2022-12-21 17:48:12 +01:00

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%