linux/kernel/trace
Andrii Nakryiko d4dd9775ec bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpers
Add sleepable implementations of bpf_get_stack() and
bpf_get_task_stack() helpers and allow them to be used from sleepable
BPF program (e.g., sleepable uprobes).

Note, the stack trace IPs capturing itself is not sleepable (that would
need to be a separate project), only build ID fetching is sleepable and
thus more reliable, as it will wait for data to be paged in, if
necessary. For that we make use of sleepable build_id_parse()
implementation.

Now that build ID related internals in kernel/bpf/stackmap.c can be used
both in sleepable and non-sleepable contexts, we need to add additional
rcu_read_lock()/rcu_read_unlock() protection around fetching
perf_callchain_entry, but with the refactoring in previous commit it's
now pretty straightforward. We make sure to do rcu_read_unlock (in
sleepable mode only) right before stack_map_get_build_id_offset() call
which can sleep. By that time we don't have any more use of
perf_callchain_entry.

Note, bpf_get_task_stack() will fail for user mode if task != current.
And for kernel mode build ID are irrelevant. So in that sense adding
sleepable bpf_get_task_stack() implementation is a no-op. It feel right
to wire this up for symmetry and completeness, but I'm open to just
dropping it until we support `user && crosstask` condition.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240829174232.3133883-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11 09:58:31 -07:00
..
rv rv: Update rv_en(dis)able_monitor doc to match kernel-doc 2024-05-21 19:03:35 -04:00
blktrace.c blktrace: convert strncpy() to strscpy_pad() 2024-04-25 21:07:08 -07:00
bpf_trace.c bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpers 2024-09-11 09:58:31 -07:00
bpf_trace.h tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
error_report-traces.c
fgraph.c function_graph: Fix the ret_stack used by ftrace_graph_ret_addr() 2024-08-07 20:20:30 -04:00
fprobe.c fprobe: Fix to allocate entry_data_size buffer with rethook instances 2024-03-01 09:18:24 +09:00
ftrace_internal.h function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE 2024-06-10 18:08:23 -04:00
ftrace.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
Kconfig tracing: Build event generation tests only as modules 2024-06-12 08:43:12 +09:00
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 trace/pid_list: Change gfp flags in pid_list_fill_irq() 2024-07-15 15:07:14 -04:00
pid_list.h
power-traces.c
preemptirq_delay_test.c minmax: make generic MIN() and MAX() macros available everywhere 2024-07-28 15:49:18 -07:00
rethook.c rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get() 2024-05-01 23:18:48 +09:00
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
ring_buffer.c ring-buffer: Remove unused function ring_buffer_nr_pages() 2024-08-07 20:26:44 -04:00
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_benchmark.c tracing: Improve benchmark test performance by using do_div() 2024-05-13 20:00:57 -04:00
trace_benchmark.h
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
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
trace_events_filter_test.h
trace_events_filter.c tracing: Have trace_event_file have ref counters 2023-11-01 23:44:44 -04:00
trace_events_hist.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_inject.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -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: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_user.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
trace_events.c tracing: Use refcount for trace_event_file reference counter 2024-08-07 18:12:46 -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 '%pd' type for print struct dentry's name 2024-05-01 23:18:47 +09:00
trace_functions_graph.c function_graph: Move graph notrace bit to shadow stack global var 2024-06-04 10:37:44 -04:00
trace_functions.c ftrace: Hide one more entry in stack trace when ftrace_pid is enabled 2024-06-06 15:22:18 -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 function_graph: Move set_graph_function tests to shadow stack global var 2024-06-04 10:37:35 -04:00
trace_kdb.c
trace_kprobe_selftest.c tracing: arm64: Avoid missing-prototype warnings 2023-07-12 12:06:04 -04:00
trace_kprobe_selftest.h
trace_kprobe.c tracing/kprobes: Fix build error when find_module() is not available 2024-07-10 09:47:00 +09:00
trace_mmiotrace.c
trace_nop.c
trace_osnoise.c rtla/osnoise: set the default threshold to 1us 2024-07-01 18:54:31 -04:00
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_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_probe.c tracing/probes: fix error check in parse_btf_field() 2024-05-27 21:32:35 +09:00
trace_probe.h tracing/probes: support '%pd' type for print struct dentry's name 2024-05-01 23:18:47 +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 function_graph: Move set_graph_function tests to shadow stack global var 2024-06-04 10:37:35 -04:00
trace_selftest_dynamic.c
trace_selftest.c fgraph: Use str_plural() in test_graph_storage_single() 2024-07-01 19:57:51 -04:00
trace_seq.c trace_seq: Increase the buffer size to almost two pages 2023-12-18 23:14:16 -05:00
trace_stack.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
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 uprobes: prevent mutex_lock() under rcu_read_lock() 2024-05-24 07:44:44 +09:00
trace.c tracing: Return from tracing_buffers_read() if the file has been closed 2024-08-09 12:59:35 -04:00
trace.h tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
tracing_map.c tracing: Fix overflow in get_free_elt() 2024-08-07 20:23:12 -04:00
tracing_map.h tracing: Remove unused extern declaration tracing_map_set_field_descr() 2023-07-23 11:08:14 -04:00