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: 23722fb46725 ("coresight: Fix possible deadlock with lock dependency")

Signed-off-by: Mike Leach mike.leach@linaro.org --- drivers/hwtracing/coresight/coresight-cti-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c index c6e8c6542f24..d2cf4f4848e1 100644 --- a/drivers/hwtracing/coresight/coresight-cti-core.c +++ b/drivers/hwtracing/coresight/coresight-cti-core.c @@ -564,7 +564,7 @@ static void cti_add_assoc_to_csdev(struct coresight_device *csdev) * if we found a matching csdev then update the ECT * association pointer for the device with this CTI. */ - coresight_set_assoc_ectdev_mutex(csdev->ect_dev, + coresight_set_assoc_ectdev_mutex(csdev, ect_item->csdev); break; }