On 25/09/2024 14:13, Julien Meunier wrote:

The previous implementation limited the tracing capabilities when perf was run in the init PID namespace, making it impossible to trace applications in non-init PID namespaces.

This update improves the tracing process by verifying the event owner. This allows us to determine whether the user has the necessary permissions to trace the application.

Cc: stable@vger.kernel.org Fixes: aab473867fed ("coresight: etm4x: Don't trace PID for non-root PID namespace") Signed-off-by: Julien Meunier julien.meunier@nokia.com

Thanks for the fix, I will queue this for v6.13

Suzuki

---

drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index bf01f01964cf..8365307b1aec 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -695,7 +695,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, /* Only trace contextID when runs in root PID namespace */ if ((attr->config & BIT(ETM_OPT_CTXTID)) &&

•    task_is_in_init_pid_ns(current))
  

•    task_is_in_init_pid_ns(event->owner))
  

  /* bit[6], Context ID tracing bit */ config->cfg |= TRCCONFIGR_CID;

@@ -710,7 +710,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, goto out; } /* Only trace virtual contextID when runs in root PID namespace */

• if (task_is_in_init_pid_ns(current))
  

• if (task_is_in_init_pid_ns(event->owner))
  config->cfg |= TRCCONFIGR_VMID | TRCCONFIGR_VMIDOPT;
  

  }