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Message-Id: <20221102112003.2318583-1-james.clark@arm.com>
Date: Wed, 2 Nov 2022 11:20:03 +0000
From: James Clark <james.clark@....com>
To: stable@...nel.org
Cc: Suzuki.Poulose@....com, James Clark <james.clark@....com>,
Aishwarya TCV <Aishwarya.TCV@....com>,
Cristian Marussi <Cristian.Marussi@....com>,
Suzuki K Poulose <suzuki.poulose@....com>,
Mike Leach <mike.leach@...aro.org>,
Mathieu Poirier <mathieu.poirier@...aro.org>,
Leo Yan <leo.yan@...aro.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 5.10] coresight: cti: Fix hang in cti_disable_hw()
commit 6746eae4bbaddcc16b40efb33dab79210828b3ce upstream.
cti_enable_hw() and cti_disable_hw() are called from an atomic context
so shouldn't use runtime PM because it can result in a sleep when
communicating with firmware.
This can cause a hang when running the Perf Coresight tests or running
this command:
perf record -e cs_etm//u -- ls
With lock and scheduler debugging enabled the following is output:
coresight cti_sys0: cti_enable_hw -- dev:cti_sys0 parent: 20020000.cti
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1151
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 330, name: perf-exec
preempt_count: 2, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last enabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 3 PID: 330 Comm: perf-exec Not tainted 6.0.0-00053-g042116d99298 #7
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Sep 13 2022
Call trace:
dump_backtrace+0x134/0x140
show_stack+0x20/0x58
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
__might_resched+0x180/0x228
__might_sleep+0x50/0x88
__pm_runtime_resume+0xac/0xb0
cti_enable+0x44/0x120
coresight_control_assoc_ectdev+0xc0/0x150
coresight_enable_path+0xb4/0x288
etm_event_start+0x138/0x170
etm_event_add+0x48/0x70
event_sched_in.isra.122+0xb4/0x280
merge_sched_in+0x1fc/0x3d0
visit_groups_merge.constprop.137+0x16c/0x4b0
ctx_sched_in+0x114/0x1f0
perf_event_sched_in+0x60/0x90
ctx_resched+0x68/0xb0
perf_event_exec+0x138/0x508
begin_new_exec+0x52c/0xd40
load_elf_binary+0x6b8/0x17d0
bprm_execve+0x360/0x7f8
do_execveat_common.isra.47+0x218/0x238
__arm64_sys_execve+0x48/0x60
invoke_syscall+0x4c/0x110
el0_svc_common.constprop.4+0xfc/0x120
do_el0_svc+0x34/0xc0
el0_svc+0x40/0x98
el0t_64_sync_handler+0x98/0xc0
el0t_64_sync+0x170/0x174
Fix the issue by removing the runtime PM calls completely. They are not
needed here because it must have already been done when building the
path for a trace.
Fixes: 835d722ba10a ("coresight: cti: Initial CoreSight CTI Driver")
Cc: stable <stable@...nel.org> # 5.10.x
Reported-by: Aishwarya TCV <Aishwarya.TCV@....com>
Reported-by: Cristian Marussi <Cristian.Marussi@....com>
Suggested-by: Suzuki K Poulose <suzuki.poulose@....com>
Reviewed-by: Mike Leach <mike.leach@...aro.org>
Tested-by: Mike Leach <mike.leach@...aro.org>
[ Fix build warnings ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
Link: https://lore.kernel.org/r/20221025131032.1149459-1-suzuki.poulose@arm.com
Signed-off-by: James Clark <james.clark@....com>
---
drivers/hwtracing/coresight/coresight-cti-core.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 0276700c246d..90270696206c 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -90,11 +90,9 @@ void cti_write_all_hw_regs(struct cti_drvdata *drvdata)
static int cti_enable_hw(struct cti_drvdata *drvdata)
{
struct cti_config *config = &drvdata->config;
- struct device *dev = &drvdata->csdev->dev;
unsigned long flags;
int rc = 0;
- pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
/* no need to do anything if enabled or unpowered*/
@@ -119,7 +117,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
/* cannot enable due to error */
cti_err_not_enabled:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- pm_runtime_put(dev->parent);
return rc;
}
@@ -153,7 +150,6 @@ static void cti_cpuhp_enable_hw(struct cti_drvdata *drvdata)
static int cti_disable_hw(struct cti_drvdata *drvdata)
{
struct cti_config *config = &drvdata->config;
- struct device *dev = &drvdata->csdev->dev;
spin_lock(&drvdata->spinlock);
@@ -174,7 +170,6 @@ static int cti_disable_hw(struct cti_drvdata *drvdata)
coresight_disclaim_device_unlocked(drvdata->base);
CS_LOCK(drvdata->base);
spin_unlock(&drvdata->spinlock);
- pm_runtime_put(dev->parent);
return 0;
/* not disabled this call */
--
2.25.1
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