6.15-stable review patch. If anyone has any objections, please let me know.
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From: Yeoreum Yun yeoreum.yun@arm.com
[ Upstream commit 53b9e2659719b04f5ba7593f2af0f2335f75e94a ]
There'll be possible race scenario for coresight config:
CPU0 CPU1 (perf enable) load module cscfg_load_config_sets() activate config. // sysfs (sys_active_cnt == 1) ... cscfg_csdev_enable_active_config() lock(csdev->cscfg_csdev_lock) deactivate config // sysfs (sys_activec_cnt == 0) cscfg_unload_config_sets() <iterating config_csdev_list> cscfg_remove_owned_csdev_configs() // here load config activate by CPU1 unlock(csdev->cscfg_csdev_lock)
iterating config_csdev_list could be raced with config_csdev_list's entry delete.
To resolve this race , hold csdev->cscfg_csdev_lock() while cscfg_remove_owned_csdev_configs()
Fixes: 02bd588e12df ("coresight: configuration: Update API to permit dynamic load/unload") Signed-off-by: Yeoreum Yun yeoreum.yun@arm.com Reviewed-by: Leo Yan leo.yan@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250514161951.3427590-3-yeoreum.yun@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-syscfg.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index a70c1454b4106..23017612f2eae 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -395,6 +395,8 @@ static void cscfg_remove_owned_csdev_configs(struct coresight_device *csdev, voi if (list_empty(&csdev->config_csdev_list)) return;
+ guard(raw_spinlock_irqsave)(&csdev->cscfg_csdev_lock); + list_for_each_entry_safe(config_csdev, tmp, &csdev->config_csdev_list, node) { if (config_csdev->config_desc->load_owner == load_owner) list_del(&config_csdev->node);