Messages in this thread |  | | Date | Tue, 14 Dec 2021 10:59:58 +0000 | Subject | Re: [PATCH v2 0/4] coresight: etm: Correct PID tracing for non-root namespace | From | Suzuki K Poulose <> |
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On 13/12/2021 12:13, Leo Yan wrote: > If a profiling program runs in a non-root PID namespace, if CoreSight > driver enables PID tracing (with contextID), it can lead to mismatching > issue between the context ID traced in hardware (from the root > namespace) and the PIDs gathered by profiling tool (e.g. perf) in its > non-root namespace. > > CoreSight driver has tried to address this issue for the contextID > related interfaces under sysfs, but it misses to prevent user to set > VMID (virtual contextID) for kernel runs in EL2 with VHE; furthermore, > it misses to handle the case when the profiling tool runs in the > non-root PID namespace. > > For this reason, this patch series is to correct contextID tracing for > non-root namespace. After applied this patchset, patch 02 doesn't > permit users to access virtual contextID via sysfs nodes in the non-root > PID namespace, patch 03 and 04 stop to trace PID packet for non-root PID > namespace. > > This patch is dependent on the patchset "pid: Introduce helper > task_is_in_root_ns()" [1]. > > [1] https://lore.kernel.org/lkml/20211208083320.472503-1-leo.yan@linaro.org/ > > > Leo Yan (4): > coresight: etm4x: Add lock for reading virtual context ID comparator > coresight: etm4x: Don't use virtual contextID for non-root PID > namespace > coresight: etm4x: Don't trace PID for non-root PID namespace > coresight: etm3x: Don't trace PID for non-root PID namespace >
For the series,
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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