Daniel Xu fff7b64355 bpf: Add bpf_read_branch_records() helper ... Branch records are a CPU feature that can be configured to record certain branches that are taken during code execution. This data is particularly interesting for profile guided optimizations. perf has had branch record support for a while but the data collection can be a bit coarse grained. We (Facebook) have seen in experiments that associating metadata with branch records can improve results (after postprocessing). We generally use bpf_probe_read_*() to get metadata out of userspace. That's why bpf support for branch records is useful. Aside from this particular use case, having branch data available to bpf progs can be useful to get stack traces out of userspace applications that omit frame pointers. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200218030432.4600-2-dxu@dxuuu.xyz		2020-02-19 14:37:36 -08:00
..
blktrace.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
bpf_trace.c	bpf: Add bpf_read_branch_records() helper	2020-02-19 14:37:36 -08:00
fgraph.c	tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls	2020-01-02 21:56:44 -05:00
ftrace_internal.h	treewide: Rename rcu_dereference_raw_notrace() to _check()	2019-08-01 14:16:21 -07:00
ftrace.c	ftrace: Protect ftrace_graph_hash with ftrace_sync	2020-02-05 17:16:42 -05:00
Kconfig	tracing: Move tracing selftests to bottom of menu	2020-01-30 09:46:29 -05:00
kprobe_event_gen_test.c	tracing: Add kprobe event command generation test module	2020-01-30 09:46:28 -05:00
Makefile	tracing: Add kprobe event command generation test module	2020-01-30 09:46:28 -05:00
power-traces.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
preemptirq_delay_test.c	preemptirq_delay_test: Add the burst feature and a sysfs trigger	2019-11-13 09:37:28 -05:00
ring_buffer_benchmark.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
ring_buffer.c	ring-buffer: Remove abandoned macro RB_MISSED_FLAGS	2020-01-21 18:38:02 -05:00
rpm-traces.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
synth_event_gen_test.c	tracing: Add synth event generation test module	2020-01-30 09:46:28 -05:00
trace_benchmark.c	trace: Use pr_warn instead of pr_warning	2019-10-18 15:01:57 +02:00
trace_benchmark.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_boot.c	tracing: Change trace_boot to use synth_event interface	2020-01-31 12:59:26 -05:00
trace_branch.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_clock.c	tracing: Add SPDX License format tags to tracing files	2018-08-16 19:08:06 -04:00
trace_dynevent.c	tracing: Use seq_buf for building dynevent_cmd string	2020-02-01 13:10:15 -05:00
trace_dynevent.h	tracing: Remove check_arg() callbacks from dynevent args	2020-02-01 13:09:23 -05:00
trace_entries.h	Tracing updates:	2020-02-06 07:12:11 +00:00
trace_event_perf.c	Merge branch 'perf/urgent' into perf/core, to pick up fixes	2019-10-28 12:38:26 +01:00
trace_events_filter_test.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_events_filter.c	tracing: Avoid memory leak in process_system_preds()	2019-12-19 18:24:17 -05:00
trace_events_hist.c	Various fixes:	2020-02-11 16:39:18 -08:00
trace_events_inject.c	tracing: Initialize val to zero in parse_entry of inject code	2020-01-02 19:04:57 -05:00
trace_events_trigger.c	trigger_next should increase position index	2020-01-30 09:46:27 -05:00
trace_events.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace_export.c	Linux 5.5-rc1	2019-12-10 10:11:00 +01:00
trace_functions_graph.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_functions.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_hwlat.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace_irqsoff.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_kdb.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_kprobe_selftest.c	selftest/ftrace: Move kprobe selftest function to separate compile unit	2018-07-30 18:41:04 -04:00
trace_kprobe_selftest.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_kprobe.c	Various fixes:	2020-02-11 16:39:18 -08:00
trace_mmiotrace.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_nop.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
trace_output.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_output.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00
trace_preemptirq.c	kprobes: Prohibit probing on hardirq tracers	2019-02-13 08:16:40 +01:00
trace_printk.c	tracing: Add locked_down checks to the open calls of files created for tracefs	2019-10-12 20:48:06 -04:00
trace_probe_tmpl.h	tracing/probe: Support user-space dereference	2019-05-25 23:04:42 -04:00
trace_probe.c	tracing/kprobes: Have uname use __get_str() in print_fmt	2020-01-27 10:56:02 -05:00
trace_probe.h	tracing/uprobe: Fix to make trace_uprobe_filter alignment safe	2020-01-22 07:09:20 -05:00
trace_sched_switch.c	tracing: Fix sched switch start/stop refcount racy updates	2020-01-30 09:46:10 -05:00
trace_sched_wakeup.c	tracing: Make struct ring_buffer less ambiguous	2020-01-13 13:19:38 -05:00
trace_selftest_dynamic.c	ftrace: Mark function tracer test functions noinline/noclone	2018-01-23 15:57:29 -05:00
trace_selftest.c	tracing: Rename trace_buffer to array_buffer	2020-01-13 13:19:38 -05:00
trace_seq.c	tracing: Remove unused TRACE_SEQ_BUF_USED	2020-01-21 18:39:54 -05:00
trace_stack.c	tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined	2020-01-02 22:04:07 -05:00
trace_stat.c	tracing: Fix tracing_stat return values in error handling paths	2020-01-24 18:06:48 -05:00
trace_stat.h	tracing: Use generic type for comparator function	2019-11-14 13:15:11 -05:00
trace_syscalls.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace_uprobe.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace.c	Tracing updates:	2020-02-06 07:12:11 +00:00
trace.h	Tracing updates:	2020-02-06 07:12:11 +00:00
tracing_map.c	tracing: Have the histogram compare functions convert to u64 first	2019-12-19 18:26:00 -05:00
tracing_map.h	tracing: Fix SPDX format headers to use C++ style comments	2018-08-16 19:08:06 -04:00