Messages in this thread | | | Date | Thu, 20 Oct 2016 10:30:29 -0400 (EDT) | From | CAI Qian <> | Subject | Re: [PATCH] perf: Protect pmu device removal with pmu_bus_running check CONFIG_DEBUG_TEST_DRIVER_REMOVE kernel panic |
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> CAI Qian reported crash [1] in uncore device removal related > to CONFIG_DEBUG_TEST_DRIVER_REMOVE option. > > The reason for crash is that perf_pmu_unregister tries to remove > pmu device which is not added at this point. We add pmu devices > only after pmu_bus is registered which happens in perf_event_sysfs_init > init call and sets pmu_bus_running flag. > > The fix is to get the pmu_bus_running flag state at the point > the pmu is taken out of the pmus list and remove the device > later only if it's set. > > [1] https://marc.info/?l=linux-kernel&m=147688837328451 > > Reported-by: CAI Qian <caiqian@redhat.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: CAI Qian <caiqian@redhat.com>
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