linux/kernel/trace
Tahsin Erdogan 9c5afa726a tracing: Fix trace_pipe behavior for instance traces
commit 75df6e688c upstream.

When reading data from trace_pipe, tracing_wait_pipe() performs a
check to see if tracing has been turned off after some data was read.
Currently, this check always looks at global trace state, but it
should be checking the trace instance where trace_pipe is located at.

Because of this bug, cat instances/i1/trace_pipe in the following
script will immediately exit instead of waiting for data:

cd /sys/kernel/debug/tracing
echo 0 > tracing_on
mkdir -p instances/i1
echo 1 > instances/i1/tracing_on
echo 1 > instances/i1/events/sched/sched_process_exec/enable
cat instances/i1/trace_pipe

Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com

Fixes: 10246fa35d ("tracing: give easy way to clear trace buffer")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-05 09:41:44 +02:00
..
blktrace.c Most of the changes are clean ups and small fixes. Some of them have 2015-11-06 13:30:20 -08:00
bpf_trace.c bpf: make tracing helpers gpl only 2015-10-26 21:53:34 -07:00
ftrace.c ftrace: Fix memleak when unregistering dynamic ops when tracing disabled 2017-09-27 11:00:17 +02:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-11-10 18:11:41 -08:00
Makefile Makefile: Mute warning for __builtin_return_address(>0) for tracing only 2016-09-30 10:18:35 +02:00
power-traces.c PM / sleep: export suspend_resume trace event 2015-01-30 02:10:41 +01:00
ring_buffer_benchmark.c ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark 2015-11-03 16:19:02 -05:00
ring_buffer.c ring-buffer: Have ring_buffer_iter_empty() return true when empty 2017-04-27 09:09:31 +02:00
rpm-traces.c
trace_benchmark.c tracing: Only benchmark the time tracepoints take if tracing is on 2015-11-02 13:34:58 -05:00
trace_benchmark.h tracing: Add tracepoint benchmark tracepoint 2014-05-29 22:49:54 -04:00
trace_branch.c tracing: Remove {start,stop}_branch_trace 2015-10-21 10:10:09 -04:00
trace_clock.c tracing: Export tracing clock functions 2015-05-12 15:56:57 -04:00
trace_entries.h tracing: %pF is only for function pointers 2015-03-25 08:57:22 -04:00
trace_event_perf.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
trace_events_filter_test.h
trace_events_filter.c tracing: Fix freeing of filter in create_filter() when set_str is false 2017-08-30 10:19:24 +02:00
trace_events_trigger.c tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call 2015-05-13 21:48:40 -04:00
trace_events.c tracing: Don't display trigger file for events that can't be enabled 2016-05-11 11:21:13 +02:00
trace_export.c tracing: ftrace_event_is_function() can return boolean 2015-11-02 14:28:05 -05:00
trace_functions_graph.c fgraph: Handle a case where a tracer ignores set_graph_notrace 2017-01-09 08:07:50 +01:00
trace_functions.c tracing/trivial: Fix typos and make an int into a bool 2014-11-20 10:05:36 -05:00
trace_irqsoff.c tracing: Have preempt(irqs)off trace preempt disabled functions 2016-04-12 09:08:59 -07:00
trace_kdb.c tracing: Move trace_flags from global to a trace_array field 2015-09-30 15:22:55 -04:00
trace_kprobe.c tracing/kprobes: Allow to create probe with a module name starting with a digit 2017-07-15 11:57:45 +02:00
trace_mmiotrace.c tracing: Pass trace_array into trace_buffer_unlock_commit() 2015-09-25 17:38:44 -04:00
trace_nop.c tracing: Remove unneeded includes of debugfs.h and fs.h 2015-01-22 11:19:48 -05:00
trace_output.c tracing: Move trace_flags from global to a trace_array field 2015-09-30 15:22:55 -04:00
trace_output.h tracing: Turn seq_print_user_ip() into a static function 2015-09-28 10:16:12 -04:00
trace_printk.c tracing: Handle NULL formats in hold_module_trace_bprintk_format() 2016-07-27 09:47:32 -07:00
trace_probe.c trace: Don't use __weak in header files 2015-03-25 08:57:23 -04:00
trace_probe.h kernel/trace_probe: is_good_name can be boolean 2015-09-22 13:11:30 -04:00
trace_sched_switch.c sched/core: Fix trace_sched_switch() 2015-10-06 17:08:15 +02:00
trace_sched_wakeup.c Most of the changes are clean ups and small fixes. Some of them have 2015-11-06 13:30:20 -08:00
trace_selftest_dynamic.c
trace_selftest.c ftrace: Fix selftest goto location on error 2017-09-27 11:00:16 +02:00
trace_seq.c tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
trace_stack.c tracing/stacktrace: Show entire trace if passed in function not found 2016-02-17 12:30:57 -08:00
trace_stat.c tracing: Convert the tracing facility over to use tracefs 2015-02-03 12:48:41 -05:00
trace_stat.h
trace_syscalls.c tracing: Move trace_flags from global to a trace_array field 2015-09-30 15:22:55 -04:00
trace_uprobe.c tracing/uprobes: Do not print '0x (null)' when offset is 0 2015-08-26 10:43:01 -03:00
trace.c tracing: Fix trace_pipe behavior for instance traces 2017-10-05 09:41:44 +02:00
trace.h tracing: Remove unused ftrace_cpu_disabled per cpu variable 2015-11-07 13:25:14 -05:00