ETMv3 driver enables PID tracing by directly using perf config from
userspace, this means the tracer will capture PID packets from root
namespace but the profiling session runs in non-root PID namespace.
Finally, the recorded packets can mislead perf reporting with the
mismatched PID values.
This patch changes to only enable PID tracing for root PID namespace.
Note, the hardware supports VMID tracing from ETMv3.5, but the driver
never enables VMID trace, this patch doesn't handle VMID trace (bit 30
in ETMCR register) particularly.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220204152403.71775-5-leo.yan@linaro.org
Functions that are annotated __exit are discarded for built-in drivers,
but the .remove callback in a device driver must still be kept around
to allow bind/unbind operations.
There is now a linker warning for the discarded symbol references:
`tmc_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tmc-core.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tmc-core.o
`tpiu_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpiu.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpiu.o
`etb_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-etb10.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-etb10.o
`static_funnel_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-funnel.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-funnel.o
`dynamic_funnel_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-funnel.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-funnel.o
`static_replicator_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-replicator.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-replicator.o
`dynamic_replicator_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-replicator.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-replicator.o
`catu_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-catu.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-catu.o
Remove all those annotations.
Fixes: 8b0cf82677 ("coresight: stm: Allow to build coresight-stm as a module")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201208182651.1597945-3-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>