Frederic Weisbecker f3b9aae162 tracing/ring-buffer: Add unlock recursion protection on discard ... The pair of helpers trace_recursive_lock() and trace_recursive_unlock() have been introduced recently to provide generic tracing recursion protection. They are used in a symetric way: - trace_recursive_lock() on buffer reserve - trace_recursive_unlock() on buffer commit However sometimes, we don't commit but discard on entry to the buffer, ie: in case of filter checking. Then we must also unlock the recursion protection on discard time, otherwise the tracing gets definitely deactivated and a warning is raised spuriously, such as: 111.119821] ------------[ cut here ]------------ [ 111.119829] WARNING: at kernel/trace/ring_buffer.c:1498 ring_buffer_lock_reserve+0x1b7/0x1d0() [ 111.119835] Hardware name: AMILO Li 2727 [ 111.119839] Modules linked in: [ 111.119846] Pid: 5731, comm: Xorg Tainted: G W 2.6.30-rc1 #69 [ 111.119851] Call Trace: [ 111.119863] [<ffffffff8025ce68>] warn_slowpath+0xd8/0x130 [ 111.119873] [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0 [ 111.119882] [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0 [ 111.119891] [<ffffffff802199b0>] ? native_sched_clock+0x20/0x70 [ 111.119899] [<ffffffff80286dee>] ? put_lock_stats+0xe/0x30 [ 111.119906] [<ffffffff80286eb8>] ? lock_release_holdtime+0xa8/0x150 [ 111.119913] [<ffffffff802c8ae7>] ring_buffer_lock_reserve+0x1b7/0x1d0 [ 111.119921] [<ffffffff802cd110>] trace_buffer_lock_reserve+0x30/0x70 [ 111.119930] [<ffffffff802ce000>] trace_current_buffer_lock_reserve+0x20/0x30 [ 111.119939] [<ffffffff802474e8>] ftrace_raw_event_sched_switch+0x58/0x100 [ 111.119948] [<ffffffff808103b7>] __schedule+0x3a7/0x4cd [ 111.119957] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.119964] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.119971] [<ffffffff80810c08>] schedule+0x18/0x40 [ 111.119977] [<ffffffff80810e09>] preempt_schedule+0x39/0x60 [ 111.119985] [<ffffffff80813bd3>] _read_unlock+0x53/0x60 [ 111.119993] [<ffffffff807259d2>] sock_def_readable+0x72/0x80 [ 111.120002] [<ffffffff807ad5ed>] unix_stream_sendmsg+0x24d/0x3d0 [ 111.120011] [<ffffffff807219a3>] sock_aio_write+0x143/0x160 [ 111.120019] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120026] [<ffffffff80721860>] ? sock_aio_write+0x0/0x160 [ 111.120033] [<ffffffff80721860>] ? sock_aio_write+0x0/0x160 [ 111.120042] [<ffffffff8031c283>] do_sync_readv_writev+0xf3/0x140 [ 111.120049] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120057] [<ffffffff80276ff0>] ? autoremove_wake_function+0x0/0x40 [ 111.120067] [<ffffffff8045d489>] ? cap_file_permission+0x9/0x10 [ 111.120074] [<ffffffff8045c1e6>] ? security_file_permission+0x16/0x20 [ 111.120082] [<ffffffff8031cab4>] do_readv_writev+0xd4/0x1f0 [ 111.120089] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120097] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120105] [<ffffffff8031cc18>] vfs_writev+0x48/0x70 [ 111.120111] [<ffffffff8031cd65>] sys_writev+0x55/0xc0 [ 111.120119] [<ffffffff80211e32>] system_call_fastpath+0x16/0x1b [ 111.120125] ---[ end trace 15605f4e98d5ccb5 ]--- [ Impact: fix spurious warning triggering tracing shutdown ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>		2009-04-20 10:59:20 +02:00
..
blktrace.c	blktrace: fix context-info when mixed-using blk tracer and trace events	2009-04-16 10:11:01 +02:00
ftrace.c	ftrace: use module notifier for function tracer	2009-04-17 16:59:15 +02:00
Kconfig	Merge branch 'linus' into tracing/core	2009-04-14 00:02:22 +02:00
kmemtrace.c	tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()	2009-04-14 00:00:56 +02:00
Makefile	tracing/events: move the ftrace event tracing code to core	2009-04-14 12:57:59 -04:00
ring_buffer.c	tracing/ring-buffer: Add unlock recursion protection on discard	2009-04-20 10:59:20 +02:00
trace_boot.c	tracing: use macros to denote usec and nsec per second	2009-04-07 14:43:06 +02:00
trace_branch.c	tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()	2009-04-14 00:00:56 +02:00
trace_clock.c	tracing: fix four sparse warnings	2009-03-22 18:16:54 +01:00
trace_event_profile.c	tracing/events: convert event call sites to use a link list	2009-04-14 12:58:00 -04:00
trace_event_types.h	tracing/filters: add TRACE_EVENT_FORMAT_NOFILTER event macro	2009-04-14 00:00:51 +02:00
trace_events_filter.c	tracing/filters: add filter_mutex to protect filter predicates	2009-04-17 18:28:27 +02:00
trace_events.c	tracing/filters: add filter_mutex to protect filter predicates	2009-04-17 18:28:27 +02:00
trace_export.c	tracing/filters: allow on-the-fly filter switching	2009-04-14 00:03:55 +02:00
trace_functions_graph.c	function-graph: add option to calculate graph time or not	2009-03-24 23:41:11 -04:00
trace_functions.c	tracing/core: use appropriate waiting on trace_pipe	2009-02-18 01:40:20 +01:00
trace_hw_branches.c	tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()	2009-04-14 00:00:56 +02:00
trace_irqsoff.c	tracing: have latency tracers set the latency format	2009-03-04 22:15:30 -05:00
trace_mmiotrace.c	tracing: use macros to denote usec and nsec per second	2009-04-07 14:43:06 +02:00
trace_nop.c	tracing/ftrace: make nop-tracer use polling wait for events on pipe	2009-03-23 09:22:15 +01:00
trace_output.c	tracing/events: add export symbols for trace events in modules	2009-04-14 12:58:01 -04:00
trace_output.h	tracing/events: move declarations from trace directory to core include	2009-04-14 12:57:58 -04:00
trace_power.c	tracing/filters: use ring_buffer_discard_commit() in filter_check_discard()	2009-04-14 00:00:56 +02:00
trace_printk.c	tracing/ftrace: factorize the tracing files creation	2009-04-07 14:43:07 +02:00
trace_sched_switch.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
trace_sched_wakeup.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
trace_selftest_dynamic.c
trace_selftest.c	tracing: keep the tracing buffer after self-test failure	2009-03-22 15:17:21 +01:00
trace_stack.c	tracing/ftrace: factorize the tracing files creation	2009-04-07 14:43:07 +02:00
trace_stat.c	Merge branch 'linus' into tracing/core	2009-04-07 13:47:45 +02:00
trace_stat.h	tracing: add handler to trace_stat	2009-03-24 23:22:58 -04:00
trace_syscalls.c	tracing/syscalls: use a dedicated file header	2009-04-09 05:43:32 +02:00
trace_sysprof.c	tracing/ftrace: factorize the tracing files creation	2009-04-07 14:43:07 +02:00
trace_workqueue.c	Merge branch 'linus' into tracing/core	2009-04-07 13:47:45 +02:00
trace.c	tracing: protect trace_printk from recursion	2009-04-17 16:21:35 -04:00
trace.h	tracing/filters: add filter_mutex to protect filter predicates	2009-04-17 18:28:27 +02:00