forked from luck/tmp_suning_uos_patched
0bbe7f7199
Traced event can trigger 'snapshot' operation(i.e. calls snapshot_trigger()
or snapshot_count_trigger()) when register_snapshot_trigger() has completed
registration but doesn't allocate buffer for 'snapshot' event trigger. In
the rare case, 'snapshot' operation always detects the lack of allocated
buffer so make register_snapshot_trigger() allocate buffer first.
trigger-snapshot.tc in kselftest reproduces the issue on slow vm:
-----------------------------------------------------------
cat trace
...
ftracetest-3028 [002] .... 236.784290: sched_process_fork: comm=ftracetest pid=3028 child_comm=ftracetest child_pid=3036
<...>-2875 [003] .... 240.460335: tracing_snapshot_instance_cond: *** SNAPSHOT NOT ALLOCATED ***
<...>-2875 [003] .... 240.460338: tracing_snapshot_instance_cond: *** stopping trace here! ***
-----------------------------------------------------------
Link: http://lkml.kernel.org/r/20200414015145.66236-1-yangx.jy@cn.fujitsu.com
Cc: stable@vger.kernel.org
Fixes:
|
||
---|---|---|
.. | ||
blktrace.c | ||
bpf_trace.c | ||
fgraph.c | ||
ftrace_internal.h | ||
ftrace.c | ||
Kconfig | ||
kprobe_event_gen_test.c | ||
Makefile | ||
power-traces.c | ||
preemptirq_delay_test.c | ||
ring_buffer_benchmark.c | ||
ring_buffer.c | ||
rpm-traces.c | ||
synth_event_gen_test.c | ||
trace_benchmark.c | ||
trace_benchmark.h | ||
trace_boot.c | ||
trace_branch.c | ||
trace_clock.c | ||
trace_dynevent.c | ||
trace_dynevent.h | ||
trace_entries.h | ||
trace_event_perf.c | ||
trace_events_filter_test.h | ||
trace_events_filter.c | ||
trace_events_hist.c | ||
trace_events_inject.c | ||
trace_events_trigger.c | ||
trace_events.c | ||
trace_export.c | ||
trace_functions_graph.c | ||
trace_functions.c | ||
trace_hwlat.c | ||
trace_irqsoff.c | ||
trace_kdb.c | ||
trace_kprobe_selftest.c | ||
trace_kprobe_selftest.h | ||
trace_kprobe.c | ||
trace_mmiotrace.c | ||
trace_nop.c | ||
trace_output.c | ||
trace_output.h | ||
trace_preemptirq.c | ||
trace_printk.c | ||
trace_probe_tmpl.h | ||
trace_probe.c | ||
trace_probe.h | ||
trace_sched_switch.c | ||
trace_sched_wakeup.c | ||
trace_selftest_dynamic.c | ||
trace_selftest.c | ||
trace_seq.c | ||
trace_stack.c | ||
trace_stat.c | ||
trace_stat.h | ||
trace_syscalls.c | ||
trace_uprobe.c | ||
trace.c | ||
trace.h | ||
tracing_map.c | ||
tracing_map.h |