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| author | Dan Williams <dan.j.williams@intel.com> | 2019-07-17 18:08:26 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2019-07-18 16:23:27 -0700 |
| commit | 87a30e1f05d73a34e6d1895065541369131aaf1c (patch) | |
| tree | a5582d3cd7723db8b7ad2f4801a5540c36c5266a /drivers/base | |
| parent | ca6bf264f6d856f959c4239cda1047b587745c67 (diff) | |
| download | linux-0-day-87a30e1f05d73a34e6d1895065541369131aaf1c.tar.gz linux-0-day-87a30e1f05d73a34e6d1895065541369131aaf1c.tar.xz | |
driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.
A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.
Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:
"Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
using it as much as anything else, so user beware :)
I don't object to it if it makes things easier for you to debug."
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index eaf3aa0cb8031..4825949d6547d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1663,6 +1663,9 @@ void device_initialize(struct device *dev) kobject_init(&dev->kobj, &device_ktype); INIT_LIST_HEAD(&dev->dma_pools); mutex_init(&dev->mutex); +#ifdef CONFIG_PROVE_LOCKING + mutex_init(&dev->lockdep_mutex); +#endif lockdep_set_novalidate_class(&dev->mutex); spin_lock_init(&dev->devres_lock); INIT_LIST_HEAD(&dev->devres_head); |