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
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
gennvm.h
/*
 * Copyright: Matias Bjorling <mb@bjorling.me>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 */

#ifndef GENNVM_H_
#define GENNVM_H_

#include <linux/module.h>
#include <linux/vmalloc.h>

#include <linux/lightnvm.h>

struct gen_lun {
	struct nvm_lun vlun;

	int reserved_blocks;
	/* lun block lists */
	struct list_head used_list;	/* In-use blocks */
	struct list_head free_list;	/* Not used blocks i.e. released
					 * and ready for use
					 */
	struct list_head bb_list;	/* Bad blocks. Mutually exclusive with
					 * free_list and used_list
					 */
};

struct gen_dev {
	struct nvm_dev *dev;

	int nr_luns;
	struct gen_lun *luns;
	struct list_head area_list;

	struct mutex lock;
	struct list_head targets;
};

struct gen_area {
	struct list_head list;
	sector_t begin;
	sector_t end;	/* end is excluded */
};

#define gen_for_each_lun(bm, lun, i) \
		for ((i) = 0, lun = &(bm)->luns[0]; \
			(i) < (bm)->nr_luns; (i)++, lun = &(bm)->luns[(i)])

#endif /* GENNVM_H_ */
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