linux-stable/kernel/trace
Steven Rostedt (Google) 2048fdc275 tracing: Decrement the snapshot if the snapshot trigger fails to register
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a snapshot trigger was added, even if that snapshot trigger
failed.

 # cd /sys/kernel/tracing
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 -bash: echo: write error: File exists

That second one that fails increments the snapshot counter but doesn't
decrement it. It needs to be decremented when the snapshot fails.

Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.729055907@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:05 -04:00
..
rv tracing/tools: Updates for 6.4 2023-04-28 16:11:26 -07:00
blktrace.c block: remove more NULL checks after bdev_get_queue() 2023-02-21 09:23:22 -07:00
bpf_trace.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
bpf_trace.h
error_report-traces.c
fgraph.c tracing: arm64: Avoid missing-prototype warnings 2023-07-12 12:06:04 -04:00
fprobe.c fprobe: Fix to allocate entry_data_size buffer with rethook instances 2024-03-01 09:18:24 +09:00
ftrace.c tracing: Fix HAVE_DYNAMIC_FTRACE_WITH_REGS ifdef 2024-02-13 11:56:49 -05:00
ftrace_internal.h tracing: arm64: Avoid missing-prototype warnings 2023-07-12 12:06:04 -04:00
Kconfig Probes updates for v6.5: 2023-06-30 10:44:53 -07:00
kprobe_event_gen_test.c tracing: Fix wrong return in kprobe_event_gen_test.c 2023-03-19 12:20:48 -04:00
Makefile tracing/probes: Move finding func-proto API and getting func-param API to trace_btf 2023-08-23 09:39:45 +09:00
pid_list.c
pid_list.h
power-traces.c
preemptirq_delay_test.c
rethook.c rethook: Use __rcu pointer for rethook::handler 2023-12-01 14:53:56 +09:00
ring_buffer.c ring-buffer: Make wake once of ring_buffer_wait() more robust 2024-03-18 10:11:43 -04:00
ring_buffer_benchmark.c ring-buffer: Read and write to ring buffers with custom sub buffer size 2023-12-20 07:54:56 -05:00
rpm-traces.c
synth_event_gen_test.c tracing / synthetic: Disable events after testing in synth_event_gen_test_init() 2023-12-21 10:04:45 -05:00
trace.c tracing: Fix snapshot counter going between two tracers that use it 2024-03-18 10:33:05 -04:00
trace.h tracing: Add snapshot refcount 2024-03-18 10:12:47 -04:00
trace_benchmark.c tracing: Add numeric delta time to the trace event benchmark 2022-09-26 13:01:09 -04:00
trace_benchmark.h tracing: Add numeric delta time to the trace event benchmark 2022-09-26 13:01:09 -04:00
trace_boot.c tracing: Allow creating instances with specified system events 2023-12-18 23:14:16 -05:00
trace_branch.c
trace_btf.c tracing/probes: Fix to search structure fields correctly 2024-02-17 21:25:42 +09:00
trace_btf.h tracing/probes: Add a function to search a member of a struct/union 2023-08-23 09:40:16 +09:00
trace_clock.c
trace_dynevent.c tracing: Free buffers when a used dynamic event is removed 2022-11-23 19:07:12 -05:00
trace_dynevent.h
trace_entries.h tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure 2023-07-30 18:11:44 -04:00
trace_eprobe.c tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_event_perf.c tracing/perf: Use strndup_user instead of kzalloc/strncpy_from_user 2022-11-23 19:08:31 -05:00
trace_events.c ring-buffer: Page size per ring buffer 2023-12-20 07:54:55 -05:00
trace_events_filter.c tracing: Have trace_event_file have ref counters 2023-11-01 23:44:44 -04:00
trace_events_filter_test.h
trace_events_hist.c tracing histograms: Simplify parse_actions() function 2024-01-08 13:24:56 -05:00
trace_events_inject.c tracing: Have event inject files inc the trace array ref count 2023-09-07 16:38:54 -04:00
trace_events_synth.c tracing/synthetic: Fix trace_string() return value 2024-02-15 11:40:01 -05:00
trace_events_trigger.c tracing: Decrement the snapshot if the snapshot trigger fails to register 2024-03-18 10:33:05 -04:00
trace_events_user.c tracing/user_events: Introduce multi-format events 2024-03-18 10:13:03 -04:00
trace_export.c tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure 2023-07-30 18:11:44 -04:00
trace_fprobe.c tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_functions.c
trace_functions_graph.c function_graph: Support recording and printing the return value of function 2023-06-20 18:38:37 -04:00
trace_hwlat.c tracing: Remove extra space at the end of hwlat_detector/mode 2023-09-01 21:00:00 -04:00
trace_irqsoff.c tracing: Fix memleak due to race between current_tracer and trace 2023-08-17 13:49:37 -04:00
trace_kdb.c
trace_kprobe.c tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_kprobe_selftest.c tracing: arm64: Avoid missing-prototype warnings 2023-07-12 12:06:04 -04:00
trace_kprobe_selftest.h
trace_mmiotrace.c
trace_nop.c
trace_osnoise.c tracing/timerlat: Move hrtimer_init to timerlat_fd open() 2024-02-01 11:50:13 -05:00
trace_output.c tracing: Remove precision vsnprintf() check from print event 2024-03-06 13:26:26 -05:00
trace_output.h tracing: Add "fields" option to show raw trace event fields 2023-03-29 06:52:08 -04:00
trace_preemptirq.c cpuidle: tracing, preempt: Squash _rcuidle tracing 2023-01-31 15:01:46 +01:00
trace_printk.c
trace_probe.c tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_probe.h tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_probe_kernel.h tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails 2023-07-14 17:04:58 +09:00
trace_probe_tmpl.h tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
trace_recursion_record.c
trace_sched_switch.c tracing: Move saved_cmdline code into trace_sched_switch.c 2024-03-17 07:58:53 -04:00
trace_sched_wakeup.c tracing: Fix memleak due to race between current_tracer and trace 2023-08-17 13:49:37 -04:00
trace_selftest.c tracing: Have function_graph selftest call cond_resched() 2023-05-28 21:15:46 -04:00
trace_selftest_dynamic.c
trace_seq.c trace_seq: Increase the buffer size to almost two pages 2023-12-18 23:14:16 -05:00
trace_stack.c
trace_stat.c
trace_stat.h
trace_synth.h tracing: Allow synthetic events to pass around stacktraces 2023-01-25 10:31:24 -05:00
trace_syscalls.c bpf: Change syscall_nr type to int in struct syscall_tp_t 2023-10-13 12:39:36 -07:00
trace_uprobe.c tracing/probes: Support $argN in return probe (kprobe and fprobe) 2024-03-07 00:27:34 +09:00
tracing_map.c tracing: Ensure visibility when inserting an element into tracing_map 2024-01-22 17:15:40 -05:00
tracing_map.h tracing: Remove unused extern declaration tracing_map_set_field_descr() 2023-07-23 11:08:14 -04:00