diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2017-02-24 14:55:48 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-24 17:46:53 -0800 |
| commit | 3fc21924100b13f73c734d0ce8dfcfe913fcf7a8 (patch) | |
| tree | 3d9f46a4936f591e5e306cf909e44fe6012efe89 | |
| parent | b5d24fda9c3dce51fcb4eee459550a458eaaf1e2 (diff) | |
mm: validate device_hotplug is held for memory hotplug
mem_hotplug_begin() assumes that it can set mem_hotplug.active_writer
and run the hotplug process without racing another thread. Validate
this assumption with a lockdep assertion.
Link: http://lkml.kernel.org/r/148693886229.16345.1770484669403334689.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/base/core.c | 5 | ||||
| -rw-r--r-- | include/linux/device.h | 1 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 2 |
3 files changed, 8 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 8c25e68e67d7..3050e6f99403 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -638,6 +638,11 @@ int lock_device_hotplug_sysfs(void) return restart_syscall(); } +void assert_held_device_hotplug(void) +{ + lockdep_assert_held(&device_hotplug_lock); +} + #ifdef CONFIG_BLOCK static inline int device_is_not_partition(struct device *dev) { diff --git a/include/linux/device.h b/include/linux/device.h index bd684fc8ec1d..a48a7ff70164 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1139,6 +1139,7 @@ static inline bool device_supports_offline(struct device *dev) extern void lock_device_hotplug(void); extern void unlock_device_hotplug(void); extern int lock_device_hotplug_sysfs(void); +void assert_held_device_hotplug(void); extern int device_offline(struct device *dev); extern int device_online(struct device *dev); extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index d67787d10ff0..92a242af5a91 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -126,6 +126,8 @@ void put_online_mems(void) void mem_hotplug_begin(void) { + assert_held_device_hotplug(); + mem_hotplug.active_writer = current; memhp_lock_acquire(); |