On Monday 11 October 2010 20:54:56 Josh Triplett wrote:

On Mon, Oct 11, 2010 at 12:52:06PM +0200, Johannes Berg wrote:

...

I don't know. Could be related to trylock issues, could be just historic since semaphores can't really be annotated, or could be something else entirely... I would expect a huge amount of warnings from sparse though if you "just" annotate them since there are things like rtnl_lock() which would have to propagate context.

As far as I know, no reason exists to not just annotate mutexes; I think mutexes just came along later and nobody happened to add the appropriate annotations. (Also, sparse does handle trylock.)

But yes, annotating mutexes will then introduce a giant pile of lock warnings that need further annotation propagation. It will also introduce lock warnings that represent actual bugs, making it important to not just blindly propagate annotations to make warnings go away.

I've given it a try, wrapping the trylock/interruptible/killable variants into macros and the number of additional warnings was much less than I had feared. This is the diff for today's sparse with today's linux-next x86_64_defconfig:

arch/x86/kernel/smpboot.c:100:6: warning: context imbalance in 'cpu_hotplug_driver_lock' - wrong count at exit arch/x86/kernel/smpboot.c:105:6: warning: context imbalance in 'cpu_hotplug_driver_unlock' - unexpected unlock kernel/cpu.c:27:6: warning: context imbalance in 'cpu_maps_update_begin' - wrong count at exit kernel/cpu.c:32:6: warning: context imbalance in 'cpu_maps_update_done' - unexpected unlock kernel/cpu.c:110:9: warning: context imbalance in 'cpu_hotplug_begin' - wrong count at exit kernel/cpu.c:120:13: warning: context imbalance in 'cpu_hotplug_done' - unexpected unlock kernel/params.c:565:6: warning: context imbalance in '__kernel_param_lock' - wrong count at exit kernel/params.c:571:6: warning: context imbalance in '__kernel_param_unlock' - unexpected unlock kernel/irq/autoprobe.c:110:9: warning: context imbalance in 'probe_irq_on' - wrong count at exit kernel/irq/autoprobe.c:145:9: warning: context imbalance in 'probe_irq_mask' - unexpected unlock kernel/irq/autoprobe.c:189:9: warning: context imbalance in 'probe_irq_off' - unexpected unlock kernel/trace/trace.c:1716:26: warning: context imbalance in 's_start' - different lock contexts for basic block kernel/trace/trace.c:303:31: warning: context imbalance in 's_stop' - unexpected unlock kernel/trace/trace.c:2277:9: warning: context imbalance in 't_start' - wrong count at exit kernel/trace/trace.c:2280:13: warning: context imbalance in 't_stop' - unexpected unlock kernel/trace/trace.c:3196:28: warning: context imbalance in 'tracing_read_pipe' - different lock contexts for basic block kernel/trace/trace.c:3349:28: warning: context imbalance in 'tracing_splice_read_pipe' - different lock contexts for basic block kernel/trace/trace.c:303:31: warning: context imbalance in 'tracing_buffers_read' - unexpected unlock kernel/trace/trace.c:303:31: warning: context imbalance in 'tracing_buffers_splice_read' - unexpected unlock kernel/trace/trace_stat.c:203:13: warning: context imbalance in 'stat_seq_start' - wrong count at exit kernel/trace/trace_stat.c:240:13: warning: context imbalance in 'stat_seq_stop' - unexpected unlock kernel/trace/trace_events.c:399:9: warning: context imbalance in 't_start' - wrong count at exit kernel/trace/trace_events.c:430:9: warning: context imbalance in 's_start' - wrong count at exit kernel/trace/trace_events.c:444:13: warning: context imbalance in 't_stop' - unexpected unlock kernel/trace/trace_kprobe.c:1064:13: warning: context imbalance in 'probes_seq_start' - wrong count at exit kernel/trace/trace_kprobe.c:1075:13: warning: context imbalance in 'probes_seq_stop' - unexpected unlock kernel/cgroup.c:737:6: warning: context imbalance in 'cgroup_lock' - wrong count at exit kernel/cgroup.c:748:6: warning: context imbalance in 'cgroup_unlock' - unexpected unlock kernel/cgroup.c:1867:6: warning: context imbalance in 'cgroup_lock_live_group' - different lock contexts for basic block kernel/cgroup.c:2155:12: warning: context imbalance in 'cgroup_create_file' - different lock contexts for basic block kernel/cgroup.c:3273:47: warning: context imbalance in 'cgroup_lock_hierarchy' - different lock contexts for basic block kernel/cgroup.c:3291:25: warning: context imbalance in 'cgroup_unlock_hierarchy' - unexpected unlock kernel/cgroup.c:3362:9: warning: context imbalance in 'cgroup_create' - unexpected unlock kernel/cpuset.c:2449:6: warning: context imbalance in 'cpuset_unlock' - unexpected unlock kernel/audit_watch.c:439:5: warning: context imbalance in 'audit_add_watch' - unexpected unlock kernel/audit_tree.c:662:9: warning: context imbalance in 'audit_add_tree_rule' - unexpected unlock mm/shmem.c:943:9: warning: context imbalance in 'shmem_unuse_inode' - unexpected unlock mm/shmem.c:1029:9: warning: context imbalance in 'shmem_unuse' - wrong count at exit mm/mmap.c:2598:9: warning: context imbalance in 'mm_take_all_locks' - wrong count at exit mm/mmap.c:2657:9: warning: context imbalance in 'mm_drop_all_locks' - unexpected unlock mm/swapfile.c:1692:13: warning: context imbalance in 'swap_start' - wrong count at exit mm/swapfile.c:1737:13: warning: context imbalance in 'swap_stop' - unexpected unlock mm/swapfile.c:2114:17: warning: context imbalance in 'sys_swapon' - unexpected unlock fs/super.c:239:6: warning: context imbalance in 'lock_super' - wrong count at exit fs/super.c:245:6: warning: context imbalance in 'unlock_super' - unexpected unlock fs/exec.c:1079:5: warning: context imbalance in 'prepare_bprm_creds' - different lock contexts for basic block arch/x86/include/asm/current.h:14:16: warning: context imbalance in 'free_bprm' - unexpected unlock fs/exec.c:1105:6: warning: context imbalance in 'install_exec_creds' - unexpected unlock fs/pipe.c:55:9: warning: context imbalance in 'pipe_lock_nested' - wrong count at exit fs/pipe.c:71:17: warning: context imbalance in 'pipe_unlock' - unexpected unlock fs/namei.c:1346:15: warning: context imbalance in 'lock_rename' - wrong count at exit fs/namei.c:1376:6: warning: context imbalance in 'unlock_rename' - unexpected unlock fs/namei.c:1491:36: warning: context imbalance in '__open_namei_create' - unexpected unlock fs/namei.c:1730:20: warning: context imbalance in 'do_last' - different lock contexts for basic block fs/namei.c:1905:15: warning: context imbalance in 'lookup_create' - wrong count at exit fs/namei.c:2040:9: warning: context imbalance in 'sys_mknodat' - unexpected unlock fs/namei.c:2103:9: warning: context imbalance in 'sys_mkdirat' - unexpected unlock fs/namei.c:2391:9: warning: context imbalance in 'sys_symlinkat' - unexpected unlock fs/namei.c:2490:9: warning: context imbalance in 'sys_linkat' - unexpected unlock fs/namei.c:2577:9: warning: context imbalance in 'vfs_rename_dir' - different lock contexts for basic block fs/namei.c:2609:9: warning: context imbalance in 'vfs_rename_other' - different lock contexts for basic block fs/readdir.c:43:9: warning: context imbalance in 'vfs_readdir' - unexpected unlock fs/dcache.c:1792:17: warning: context imbalance in '__d_unalias' - unexpected unlock fs/libfs.c:783:9: warning: context imbalance in 'simple_attr_read' - unexpected unlock fs/libfs.c:815:9: warning: context imbalance in 'simple_attr_write' - unexpected unlock fs/direct-io.c:1095:17: warning: context imbalance in 'direct_io_worker' - unexpected unlock fs/direct-io.c:1253:9: warning: context imbalance in '__blockdev_direct_IO' - different lock contexts for basic block fs/autofs4/root.c:582:17: warning: context imbalance in 'autofs4_lookup' - unexpected unlock fs/autofs4/waitq.c:274:25: warning: context imbalance in 'validate_request' - unexpected unlock fs/autofs4/waitq.c:366:17: warning: context imbalance in 'autofs4_wait' - different lock contexts for basic block include/linux/spinlock_api_smp.h:152:27: warning: context imbalance in 'journal_lock_updates' - wrong count at exit fs/jbd/transaction.c:484:9: warning: context imbalance in 'journal_unlock_updates' - unexpected unlock fs/proc/base.c:2313:9: warning: context imbalance in 'proc_pid_attr_write' - unexpected unlock fs/proc/proc_tty.c:107:13: warning: context imbalance in 't_start' - wrong count at exit fs/proc/proc_tty.c:118:13: warning: context imbalance in 't_stop' - unexpected unlock fs/sysfs/dir.c:350:6: warning: context imbalance in 'sysfs_addrm_start' - wrong count at exit fs/sysfs/dir.c:504:6: warning: context imbalance in 'sysfs_addrm_finish' - unexpected unlock arch/x86/include/asm/current.h:14:16: warning: context imbalance in 'ata_eh_acquire' - wrong count at exit drivers/ata/libata-eh.c:495:9: warning: context imbalance in 'ata_eh_release' - unexpected unlock drivers/base/bus.c:181:17: warning: context imbalance in 'driver_unbind' - different lock contexts for basic block drivers/base/bus.c:211:17: warning: context imbalance in 'driver_bind' - different lock contexts for basic block drivers/base/bus.c:731:9: warning: context imbalance in 'bus_rescan_devices_helper' - different lock contexts for basic block drivers/base/bus.c:766:9: warning: context imbalance in 'device_reprobe' - different lock contexts for basic block drivers/base/dd.c:265:12: warning: context imbalance in '__driver_attach' - different lock contexts for basic block drivers/base/dd.c:395:17: warning: context imbalance in 'driver_detach' - different lock contexts for basic block drivers/base/power/main.c:73:6: warning: context imbalance in 'device_pm_lock' - wrong count at exit drivers/base/power/main.c:81:6: warning: context imbalance in 'device_pm_unlock' - unexpected unlock drivers/block/loop.c:1064:9: warning: context imbalance in 'loop_clr_fd' - unexpected unlock drivers/block/loop.c:1352:9: warning: context imbalance in 'lo_ioctl' - different lock contexts for basic block drivers/block/loop.c:1553:9: warning: context imbalance in 'lo_release' - different lock contexts for basic block drivers/char/tty_io.c:960:6: warning: context imbalance in 'tty_write_unlock' - unexpected unlock drivers/char/tty_io.c:966:5: warning: context imbalance in 'tty_write_lock' - wrong count at exit drivers/char/tty_io.c:1077:6: warning: context imbalance in 'tty_write_message' - wrong count at exit drivers/char/tty_mutex.c:31:9: warning: context imbalance in 'tty_lock' - wrong count at exit drivers/char/tty_mutex.c:42:9: warning: context imbalance in 'tty_unlock' - unexpected unlock drivers/char/misc.c:66:13: warning: context imbalance in 'misc_seq_start' - wrong count at exit drivers/char/misc.c:77:13: warning: context imbalance in 'misc_seq_stop' - unexpected unlock drivers/cpuidle/cpuidle.c:138:6: warning: context imbalance in 'cpuidle_pause_and_lock' - wrong count at exit drivers/cpuidle/cpuidle.c:149:6: warning: context imbalance in 'cpuidle_resume_and_unlock' - unexpected unlock drivers/gpu/drm/drm_pci.c:215:9: warning: context imbalance in 'drm_get_pci_dev' - unexpected unlock drivers/gpu/drm/i915/i915_debugfs.c:202:9: warning: context imbalance in 'i915_gem_object_info' - unexpected unlock drivers/gpu/drm/i915/i915_debugfs.c:827:9: warning: context imbalance in 'i915_emon_status' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:144:12: warning: context imbalance in 'i915_mutex_lock_interruptible' - different lock contexts for basic block drivers/gpu/drm/i915/i915_gem.c:417:9: warning: context imbalance in 'i915_gem_shmem_pread_fast' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:554:9: warning: context imbalance in 'i915_gem_shmem_pread_slow' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:706:17: warning: context imbalance in 'i915_gem_gtt_pwrite_fast' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:847:9: warning: context imbalance in 'i915_gem_gtt_pwrite_slow' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:918:9: warning: context imbalance in 'i915_gem_shmem_pwrite_fast' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:1032:9: warning: context imbalance in 'i915_gem_shmem_pwrite_slow' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:1184:35: warning: context imbalance in 'i915_gem_set_domain_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:1217:35: warning: context imbalance in 'i915_gem_sw_finish_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:1529:43: warning: context imbalance in 'i915_gem_mmap_gtt_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:3770:17: warning: context imbalance in 'i915_gem_do_execbuffer' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:4248:43: warning: context imbalance in 'i915_gem_pin_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:4310:43: warning: context imbalance in 'i915_gem_unpin_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:4375:35: warning: context imbalance in 'i915_gem_busy_ioctl' - unexpected unlock drivers/gpu/drm/i915/i915_gem.c:4419:43: warning: context imbalance in 'i915_gem_madvise_ioctl' - unexpected unlock drivers/hid/usbhid/hid-core.c:127:47: warning: context imbalance in 'hid_reset' - unexpected unlock drivers/input/input.c:1021:13: warning: context imbalance in 'input_devices_seq_start' - different lock contexts for basic block drivers/input/input.c:1050:17: warning: context imbalance in 'input_seq_stop' - unexpected unlock drivers/input/input.c:1143:13: warning: context imbalance in 'input_handlers_seq_start' - different lock contexts for basic block drivers/input/mouse/psmouse-base.c:1534:9: warning: context imbalance in 'psmouse_attr_set_helper' - unexpected unlock drivers/input/serio/i8042.c:129:6: warning: context imbalance in 'i8042_lock_chip' - wrong count at exit drivers/input/serio/i8042.c:135:6: warning: context imbalance in 'i8042_unlock_chip' - unexpected unlock drivers/input/serio/libps2.c:62:9: warning: context imbalance in 'ps2_begin_command' - wrong count at exit drivers/input/serio/libps2.c:72:9: warning: context imbalance in 'ps2_end_command' - unexpected unlock drivers/md/dm.c:2088:6: warning: context imbalance in 'dm_lock_md_type' - wrong count at exit drivers/md/dm.c:2093:6: warning: context imbalance in 'dm_unlock_md_type' - unexpected unlock drivers/md/md.c:578:17: warning: context imbalance in 'mddev_unlock' - unexpected unlock drivers/md/md.c:546:19: warning: context imbalance in 'rdev_size_store' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'rdev_attr_show' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'rdev_attr_store' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'md_attr_show' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'md_attr_store' - different lock contexts for basic block drivers/md/md.c:4871:17: warning: context imbalance in 'autorun_devices' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'md_ioctl' - different lock contexts for basic block drivers/md/md.c:5911:9: warning: context imbalance in 'md_open' - different lock contexts for basic block drivers/md/md.c:546:19: warning: context imbalance in 'md_seq_show' - different lock contexts for basic block drivers/md/md.c:6985:6: warning: context imbalance in 'md_check_recovery' - different lock contexts for basic block drivers/md/md.c:7180:17: warning: context imbalance in 'md_notify_reboot' - different lock contexts for basic block drivers/pci/pci.c:2494:30: warning: context imbalance in 'pci_dev_reset' - unexpected unlock drivers/pcmcia/rsrc_nonstatic.c:281:17: warning: context imbalance in 'readable' - unexpected unlock drivers/serial/serial_core.c:1546:26: warning: context imbalance in 'uart_get' - different lock contexts for basic block drivers/serial/serial_core.c:1632:17: warning: context imbalance in 'uart_open' - unexpected unlock drivers/thermal/thermal_sys.c:74:9: warning: context imbalance in 'get_idr' - different lock contexts for basic block drivers/thermal/thermal_sys.c:88:9: warning: context imbalance in 'release_idr' - different lock contexts for basic block drivers/usb/class/usblp.c:842:9: warning: context imbalance in 'usblp_read' - unexpected unlock arch/x86/include/asm/current.h:14:16: warning: context imbalance in 'usblp_rwait_and_lock' - different lock contexts for basic block drivers/usb/core/usb.c:561:5: warning: context imbalance in 'usb_lock_device_for_reset' - different lock contexts for basic block drivers/usb/core/message.c:1605:17: warning: context imbalance in '__usb_queue_reset_device' - unexpected unlock drivers/usb/storage/transport.c:1315:17: warning: context imbalance in 'usb_stor_port_reset' - unexpected unlock drivers/usb/storage/usb.c:191:5: warning: context imbalance in 'usb_stor_pre_reset' - wrong count at exit drivers/usb/storage/usb.c:203:5: warning: context imbalance in 'usb_stor_post_reset' - unexpected unlock drivers/video/fbmem.c:48:5: warning: context imbalance in 'lock_fb_info' - wrong count at exit drivers/video/fbmem.c:1047:17: warning: context imbalance in 'do_fb_ioctl' - unexpected unlock drivers/video/fbmem.c:1608:9: warning: context imbalance in 'register_framebuffer' - unexpected unlock drivers/video/fbmem.c:1646:9: warning: context imbalance in 'unregister_framebuffer' - unexpected unlock drivers/video/fbmem.c:1696:23: warning: context imbalance in 'fb_set_suspend' - unexpected unlock drivers/video/fbmem.c:1768:17: warning: context imbalance in 'fb_new_modelist' - unexpected unlock drivers/video/fbcmap.c:276:23: warning: context imbalance in 'fb_set_user_cmap' - unexpected unlock drivers/video/console/fbcon.c:2299:9: warning: context imbalance in 'fbcon_generic_blank' - unexpected unlock sound/core/sound.c:124:25: warning: context imbalance in 'autoload_device' - unexpected unlock net/netfilter/core.c:40:9: warning: context imbalance in 'nf_register_afinfo' - unexpected unlock net/netfilter/core.c:71:21: warning: context imbalance in 'nf_register_hook' - unexpected unlock net/netfilter/nf_log.c:132:13: warning: context imbalance in 'seq_start' - wrong count at exit net/netfilter/nf_log.c:152:13: warning: context imbalance in 'seq_stop' - unexpected unlock net/netfilter/x_tables.c:710:17: warning: context imbalance in 'xt_find_table_lock' - different lock contexts for basic block net/netfilter/x_tables.c:726:6: warning: context imbalance in 'xt_table_unlock' - unexpected unlock net/netfilter/x_tables.c:733:6: warning: context imbalance in 'xt_compat_lock' - wrong count at exit net/netfilter/x_tables.c:739:6: warning: context imbalance in 'xt_compat_unlock' - unexpected unlock net/netfilter/x_tables.c:876:9: warning: context imbalance in 'xt_register_table' - unexpected unlock net/netfilter/x_tables.c:903:13: warning: context imbalance in 'xt_table_seq_start' - wrong count at exit net/netfilter/x_tables.c:922:13: warning: context imbalance in 'xt_table_seq_stop' - unexpected unlock net/netfilter/x_tables.c:985:13: warning: context imbalance in 'xt_mttg_seq_next' - wrong count at exit net/netfilter/x_tables.c:1044:17: warning: context imbalance in 'xt_mttg_seq_stop' - unexpected unlock net/netlink/genetlink.c:24:6: warning: context imbalance in 'genl_lock' - wrong count at exit net/netlink/genetlink.c:30:6: warning: context imbalance in 'genl_unlock' - unexpected unlock net/unix/af_unix.c:919:9: warning: context imbalance in 'unix_bind' - different lock contexts for basic block net/wireless/core.c:150:9: warning: context imbalance in 'cfg80211_get_dev_from_info' - different lock contexts for basic block net/wireless/core.c:172:9: warning: context imbalance in 'cfg80211_get_dev_from_ifindex' - wrong count at exit net/wireless/core.h:191:9: warning: context imbalance in 'cfg80211_wext_siwscan' - unexpected unlock net/wireless/core.h:191:9: warning: context imbalance in 'cfg80211_wext_giwscan' - unexpected unlock net/wireless/core.h:191:9: warning: context imbalance in 'nl80211_finish_netdev_dump' - unexpected unlock net/wireless/nl80211.c:901:12: warning: context imbalance in 'nl80211_set_wiphy' - different lock contexts for basic block net/wireless/core.h:191:9: warning: context imbalance in 'nl80211_pre_doit' - unexpected unlock net/wireless/core.h:191:9: warning: context imbalance in 'nl80211_post_doit' - unexpected unlock

And this is the patch I used for testing. There may still be some flaws in it, but it seems to do the trick.

Signed-off-by: Arnd Bergmann arnd@arndb.de

diff --git a/include/linux/mutex.h b/include/linux/mutex.h index f363bc8..d4940af 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -14,6 +14,7 @@ #include <linux/spinlock_types.h> #include <linux/linkage.h> #include <linux/lockdep.h> +#include <linux/compiler.h>

#include <asm/atomic.h>

@@ -131,20 +132,35 @@ static inline int mutex_is_locked(struct mutex *lock) * Also see Documentation/mutex-design.txt. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC -extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass); -extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock, - unsigned int subclass); -extern int __must_check mutex_lock_killable_nested(struct mutex *lock, - unsigned int subclass); - +extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass) + __acquires(lock); +extern int __must_check __mutex_lock_interruptible_nested(struct mutex *lock, + unsigned int subclass); +extern int __must_check __mutex_lock_killable_nested(struct mutex *lock, + unsigned int subclass); +#define mutex_lock_interruptible_nested(lock, subclass) ({ \ + int __mutex_ret = __mutex_lock_interruptible_nested(lock, subclass); \ + if (!__mutex_ret) __acquire(lock); __mutex_ret; \ +}) +#define mutex_lock_killable_nested(lock, subclass) ({ \ + int __mutex_ret = __mutex_lock_killable_nested(lock, subclass); \ + if (!__mutex_ret) __acquire(lock); __mutex_ret; \ +}) #define mutex_lock(lock) mutex_lock_nested(lock, 0) #define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0) #define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0) #else -extern void mutex_lock(struct mutex *lock); -extern int __must_check mutex_lock_interruptible(struct mutex *lock); -extern int __must_check mutex_lock_killable(struct mutex *lock); - +extern void mutex_lock(struct mutex *lock) __acquires(lock); +extern int __must_check __mutex_lock_interruptible(struct mutex *lock); +extern int __must_check __mutex_lock_killable(struct mutex *lock); +#define mutex_lock_interruptible(lock) ({ \ + int __mutex_ret = __mutex_lock_interruptible(lock); \ + if (!__mutex_ret) __acquire(lock); __mutex_ret; \ +}) +#define mutex_lock_killable(lock) ({ \ + int __mutex_ret = __mutex_lock_killable(lock); \ + if (!__mutex_ret) __acquire(lock); __mutex_ret; \ +}) # define mutex_lock_nested(lock, subclass) mutex_lock(lock) # define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock) # define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock) @@ -156,8 +172,16 @@ extern int __must_check mutex_lock_killable(struct mutex *lock); * * Returns 1 if the mutex has been acquired successfully, and 0 on contention. */ -extern int mutex_trylock(struct mutex *lock); -extern void mutex_unlock(struct mutex *lock); -extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); +extern int __mutex_trylock(struct mutex *lock); +#define mutex_trylock(lock) ({ \ + int __mutex_ret = __mutex_trylock(lock); \ + if (__mutex_ret) __acquire(lock); __mutex_ret; \ +}) +extern void mutex_unlock(struct mutex *lock) __releases(lock); +extern int __atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); +#define atomic_dec_and_mutex_lock(cnt, lock) ({ \ + int __mutex_ret = __atomic_dec_and_mutex_lock(cnt, lock); \ + if (__mutex_ret) __acquire(lock); __mutex_ret; \ +})

#endif diff --git a/kernel/mutex.c b/kernel/mutex.c index 200407c..09b70b7 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -282,22 +282,22 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass) EXPORT_SYMBOL_GPL(mutex_lock_nested);

int __sched -mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass) +__mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_KILLABLE, subclass, _RET_IP_); } -EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); +EXPORT_SYMBOL_GPL(__mutex_lock_killable_nested);

int __sched -mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass) +__mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, _RET_IP_); }

-EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); +EXPORT_SYMBOL_GPL(__mutex_lock_interruptible_nested); #endif

/* @@ -366,7 +366,7 @@ __mutex_lock_interruptible_slowpath(atomic_t *lock_count); * * This function is similar to (but not equivalent to) down_interruptible(). */ -int __sched mutex_lock_interruptible(struct mutex *lock) +int __sched __mutex_lock_interruptible(struct mutex *lock) { int ret;

@@ -379,9 +379,9 @@ int __sched mutex_lock_interruptible(struct mutex *lock) return ret; }

-EXPORT_SYMBOL(mutex_lock_interruptible); +EXPORT_SYMBOL(__mutex_lock_interruptible);

-int __sched mutex_lock_killable(struct mutex *lock) +int __sched __mutex_lock_killable(struct mutex *lock) { int ret;

@@ -393,7 +393,7 @@ int __sched mutex_lock_killable(struct mutex *lock)

return ret; } -EXPORT_SYMBOL(mutex_lock_killable); +EXPORT_SYMBOL(__mutex_lock_killable);

static __used noinline void __sched __mutex_lock_slowpath(atomic_t *lock_count) @@ -461,7 +461,7 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count) * This function must not be used in interrupt context. The * mutex must be released by the same task that acquired it. */ -int __sched mutex_trylock(struct mutex *lock) +int __sched __mutex_trylock(struct mutex *lock) { int ret;

@@ -471,7 +471,7 @@ int __sched mutex_trylock(struct mutex *lock)

return ret; } -EXPORT_SYMBOL(mutex_trylock); +EXPORT_SYMBOL(__mutex_trylock);

/** * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0 @@ -480,7 +480,7 @@ EXPORT_SYMBOL(mutex_trylock); * * return true and hold lock if we dec to 0, return false otherwise */ -int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) +int __atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) { /* dec if we can't possibly hit 0 */ if (atomic_add_unless(cnt, -1, 1)) @@ -495,4 +495,4 @@ int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) /* we hit 0, and we hold the lock */ return 1; } -EXPORT_SYMBOL(atomic_dec_and_mutex_lock); +EXPORT_SYMBOL(__atomic_dec_and_mutex_lock);