Messages in this thread | | | Date | Tue, 16 Nov 2021 13:52:52 +0000 | Subject | Re: [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace | From | Suzuki K Poulose <> |
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Hi Leo
On 31/10/2021 14:42, Leo Yan wrote: > If a profiling program runs in a non-root PID namespace, if CoreSight > driver enables contextID tracing, it can lead to mismatching issue > between the context ID in hardware trace data and the allocated PID in > the non-root namespace. > > CoreSight driver has tried to address this issue for the contextID > related interfaces under sysfs, but it misses other parts: it doesn't > prevent user to set VMID (virtual contextID) for kernel runs in EL2 with > VHE, and furthermore, it misses to handle the perf mode when the > profiling tool (e.g. perf) doesn't run in root PID namespace. > > For this reason, this patch series is to correct contextID tracing for > non-root namespace. > > Patch 01 is to use spinlock to protect reading virtual context ID > comparator. > > Patch 02 corrects the virtual contextID tracing for non-root PID > namespace. > > Patch 03/04 are used to fix the contextID tracing for perf mode. > > I only verified this patch series on Juno board in the root PID > namespace and confirmed the patches don't introduce any regression for > root PID namespace. >
I have finished reviewing the set.
Suzuki
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