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Revision 0933840acf7b65d6d30a5b6089d882afea57aca3 authored by Jiri Olsa on 20 October 2016, 11:10:11 UTC, committed by Ingo Molnar on 28 October 2016, 09:06:25 UTC 
perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic
 
CAI Qian reported a crash in the PMU uncore device removal code,
enabled by the CONFIG_DEBUG_TEST_DRIVER_REMOVE=y option:

  https://marc.info/?l=linux-kernel&m=147688837328451

The reason for the crash is that perf_pmu_unregister() tries to remove
a PMU device which is not added at this point. We add PMU devices
only after pmu_bus is registered, which happens in the
perf_event_sysfs_init() call and sets the '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 PMU list and remove the device
later only if it's set.

Reported-by: CAI Qian <caiqian@redhat.com>
Tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161020111011.GA13361@krava
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent 889882b
Raw File
Kconfig 
# ALSA PowerMac drivers

menuconfig SND_PPC
	bool "PowerPC sound devices"
	depends on PPC
	default y
	help
	  Support for sound devices specific to PowerPC architectures.

if SND_PPC

config SND_POWERMAC
	tristate "PowerMac (AWACS, DACA, Burgundy, Tumbler, Keywest)"
	depends on I2C && INPUT && PPC_PMAC
	select SND_PCM
	select SND_VMASTER
	help
	  Say Y here to include support for the integrated sound device.

	  To compile this driver as a module, choose M here: the module
	  will be called snd-powermac.

config SND_POWERMAC_AUTO_DRC
	bool "Toggle DRC automatically at headphone/line plug-in"
	depends on SND_POWERMAC
	default y
	help
	  Say Y here to enable the automatic toggle of DRC (dynamic
	  range compression) on Tumbler/Snapper.
	  If this feature is enabled, DRC is turned off when the
	  headphone/line jack is plugged, and turned on when unplugged.

	  Note that you can turn on/off DRC manually even without this
	  option.

config SND_PS3
	tristate "PS3 Audio support"
	depends on PS3_PS3AV
	select SND_PCM
	default m
	help
	  Say Y here to include support for audio on the PS3

	  To compile this driver as a module, choose M here: the module
	  will be called snd_ps3.

config SND_PS3_DEFAULT_START_DELAY
	int "Startup delay time in ms"
	depends on SND_PS3
	default "2000"

endif	# SND_PPC
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