linux/kernel/trace
Jiri Olsa e2bb9e01d5 bpf: Remove trace_printk_lock
Both bpf_trace_printk and bpf_trace_vprintk helpers use static buffer guarded
with trace_printk_lock spin lock.

The spin lock contention causes issues with bpf programs attached to
contention_begin tracepoint [1][2].

Andrii suggested we could get rid of the contention by using trylock, but we
could actually get rid of the spinlock completely by using percpu buffers the
same way as for bin_args in bpf_bprintf_prepare function.

Adding new return 'buf' argument to struct bpf_bprintf_data and making
bpf_bprintf_prepare to return also the buffer for printk helpers.

  [1] https://lore.kernel.org/bpf/CACkBjsakT_yWxnSWr4r-0TpPvbKm9-OBmVUhJb7hV3hY8fdCkw@mail.gmail.com/
  [2] https://lore.kernel.org/bpf/CACkBjsaCsTovQHFfkqJKto6S4Z8d02ud1D7MPESrHa1cVNNTrw@mail.gmail.com/

Reported-by: Hao Sun <sunhao.th@gmail.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221215214430.1336195-4-jolsa@kernel.org
2022-12-19 22:08:37 +01:00
..
rv rv/monitor: Add __init/__exit annotations to module init/exit funcs 2022-09-26 18:10:51 -04:00
Kconfig ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses 2022-11-18 13:56:41 +00:00
Makefile rv: Add Runtime Verification (RV) interface 2022-07-30 14:01:28 -04:00
blktrace.c blktrace: Fix output non-blktrace event when blk_classic option enabled 2022-12-08 09:26:11 -07:00
bpf_trace.c bpf: Remove trace_printk_lock 2022-12-19 22:08:37 +01:00
bpf_trace.h bpf: Use dedicated bpf_trace_printk event instead of trace_printk() 2020-07-13 16:55:49 -07:00
error_report-traces.c tracing: add error_report_end trace point 2021-02-26 09:41:02 -08:00
fgraph.c arm64 fixes for 5.19-rc1: 2022-06-03 14:05:34 -07:00
fprobe.c tracing/fprobe: Fix to check whether fprobe is registered correctly 2022-11-04 08:50:07 +09:00
ftrace.c Networking changes for 6.2. 2022-12-13 15:47:48 -08:00
ftrace_internal.h
kprobe_event_gen_test.c tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit() 2022-11-18 10:15:34 +09:00
pid_list.c tracing: Cleanup double word in comment 2022-04-26 17:58:50 -04:00
pid_list.h tracing: Create a sparse bitmask for pid filtering 2021-10-05 17:38:45 -04:00
power-traces.c
preemptirq_delay_test.c kernel: trace: preemptirq_delay_test: add cpu affinity 2021-02-02 17:02:07 -05:00
rethook.c rethook: fix a potential memleak in rethook_alloc() 2022-11-18 10:15:34 +09:00
ring_buffer.c ring_buffer: Do not deactivate non-existant pages 2022-11-17 17:10:40 -05:00
ring_buffer_benchmark.c sched,tracing: Convert to sched_set_fifo() 2020-07-29 11:43:53 +02:00
rpm-traces.c
synth_event_gen_test.c tracing: Fix memory leak in test_gen_synth_cmd() and test_empty_synth_event() 2022-11-17 17:51:38 -05:00
trace.c tracing: Add tracing_reset_all_online_cpus_unlocked() function 2022-11-23 19:06:11 -05:00
trace.h tracing: Add tracing_reset_all_online_cpus_unlocked() function 2022-11-23 19:06:11 -05:00
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: Initialize integer variable to prevent garbage return value 2022-05-26 21:13:00 -04:00
trace_branch.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_clock.c tracing: Do no increment trace_clock_global() by one 2021-06-18 09:10:00 -04:00
trace_dynevent.c tracing: Free buffers when a used dynamic event is removed 2022-11-23 19:07:12 -05:00
trace_dynevent.h tracing: Add DYNAMIC flag for dynamic events 2021-08-18 18:10:32 -04:00
trace_entries.h trace: Add timerlat tracer 2021-06-25 19:57:24 -04:00
trace_eprobe.c tracing/probes: Fixes for v6.1 2022-11-20 15:31:20 -08:00
trace_event_perf.c tracing/perf: Fix double put of trace event when init fails 2022-08-21 15:56:07 -04:00
trace_events.c tracing: Free buffers when a used dynamic event is removed 2022-11-23 19:07:12 -05:00
trace_events_filter.c tracing/filter: Call filter predicate functions directly via a switch statement 2022-09-26 13:01:10 -04:00
trace_events_filter_test.h
trace_events_hist.c tracing: Fix race where histograms can be called before the event 2022-11-23 19:05:50 -05:00
trace_events_inject.c tracing: Support __rel_loc relative dynamic data location attribute 2021-12-06 15:37:21 -05:00
trace_events_synth.c tracing: Add tracing_reset_all_online_cpus_unlocked() function 2022-11-23 19:06:11 -05:00
trace_events_trigger.c tracing: Fix to check event_mutex is held while accessing trigger list 2022-09-06 22:26:00 -04:00
trace_events_user.c iov_iter work; most of that is about getting rid of 2022-12-12 18:29:54 -08:00
trace_export.c tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00
trace_functions.c ftrace: disable preemption when recursion locked 2021-10-27 11:21:49 -04:00
trace_functions_graph.c tracing: in_irq() cleanup 2021-10-13 18:19:41 -04:00
trace_hwlat.c trace/hwlat: make use of the helper function kthread_run_on_cpu() 2022-01-15 16:30:24 +02:00
trace_irqsoff.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_kdb.c kdb: Rename members of struct kdbtab_t 2021-07-27 17:05:06 +01:00
trace_kprobe.c tracing: Move duplicate code of trace_kprobe/eprobe.c into header 2022-10-12 13:50:00 -04:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c tracing: Remove definition of DEBUG in trace_mmiotrace.c 2021-02-02 17:02:07 -05:00
trace_nop.c
trace_osnoise.c tracing/osnoise: Fix duration type 2022-11-22 18:12:01 -05:00
trace_output.c tracing: Remove usage of list iterator after the loop body 2022-04-27 17:19:30 -04:00
trace_output.h ftrace: Add recording of functions that caused recursion 2020-11-06 08:42:26 -05:00
trace_preemptirq.c tracing: hold caller_addr to hardirq_{enable,disable}_ip 2022-09-06 22:26:00 -04:00
trace_printk.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_probe.c tracing/probes: Have kprobes and uprobes use $COMM too 2022-08-21 15:56:08 -04:00
trace_probe.h tracing/eprobe: Add eprobe filter support 2022-09-26 13:01:08 -04:00
trace_probe_kernel.h tracing: Add "(fault)" name injection to kernel probes 2022-10-12 13:50:20 -04:00
trace_probe_tmpl.h tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs 2021-08-19 09:09:03 -04:00
trace_recursion_record.c tracing: Use trace_create_file() to simplify creation of tracefs entries 2022-05-26 21:12:52 -04:00
trace_sched_switch.c sched/tracing: Append prev_state to tp args instead 2022-05-12 00:37:11 +02:00
trace_sched_wakeup.c sched/tracing: Append prev_state to tp args instead 2022-05-12 00:37:11 +02:00
trace_selftest.c tracing: Reset the function filter after completing trampoline/graph selftest 2022-05-25 16:57:37 -04:00
trace_selftest_dynamic.c
trace_seq.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_stack.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_stat.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
trace_stat.h
trace_synth.h tracing: synth events: increase max fields count 2021-09-08 15:29:16 -04:00
trace_syscalls.c tracing: Remove unused __bad_type_size() method 2022-11-17 20:21:06 -05:00
trace_uprobe.c Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
tracing_map.c tracing: Remove unused variable 'dups' 2022-10-03 12:20:31 -04:00
tracing_map.h tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00