4a32a9a818
commit d3aa3e060c4a80827eb801fc448debc9daa7c46b upstream.
Check alloc_precpu()'s return value and return an error from
dm_stats_init() if it fails. Update alloc_dev() to fail if
dm_stats_init() does.
Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup()
even if dm-stats isn't being actively used.
Fixes: fd2ed4d252 ("dm: add statistics support")
Cc: stable@vger.kernel.org
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
44 lines
987 B
C
44 lines
987 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef DM_STATS_H
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#define DM_STATS_H
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/list.h>
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int dm_statistics_init(void);
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void dm_statistics_exit(void);
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struct dm_stats {
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struct mutex mutex;
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struct list_head list; /* list of struct dm_stat */
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struct dm_stats_last_position __percpu *last;
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sector_t last_sector;
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unsigned last_rw;
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};
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struct dm_stats_aux {
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bool merged;
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unsigned long long duration_ns;
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};
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int dm_stats_init(struct dm_stats *st);
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void dm_stats_cleanup(struct dm_stats *st);
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struct mapped_device;
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int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
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char *result, unsigned maxlen);
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void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
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sector_t bi_sector, unsigned bi_sectors, bool end,
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unsigned long duration_jiffies,
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struct dm_stats_aux *aux);
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static inline bool dm_stats_used(struct dm_stats *st)
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{
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return !list_empty(&st->list);
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}
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#endif
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