android_kernel_samsung_sm8650/kernel/trace
Masami Hiramatsu ab51e15d53 fprobe: Introduce FPROBE_FL_KPROBE_SHARED flag for fprobe
Introduce FPROBE_FL_KPROBE_SHARED flag for sharing fprobe callback with
kprobes safely from the viewpoint of recursion.

Since the recursion safety of the fprobe (and ftrace) is a bit different
from the kprobes, this may cause an issue if user wants to run the same
code from the fprobe and the kprobes.

The kprobes has per-cpu 'current_kprobe' variable which protects the
kprobe handler from recursion in any case. On the other hand, the fprobe
uses only ftrace_test_recursion_trylock(), which will allow interrupt
context calls another (or same) fprobe during the fprobe user handler is
running.

This is not a matter in cases if the common callback shared among the
kprobes and the fprobe has its own recursion detection, or it can handle
the recursion in the different contexts (normal/interrupt/NMI.)
But if it relies on the 'current_kprobe' recursion lock, it has to check
kprobe_running() and use kprobe_busy_*() APIs.

Fprobe has FPROBE_FL_KPROBE_SHARED flag to do this. If your common callback
code will be shared with kprobes, please set FPROBE_FL_KPROBE_SHARED
*before* registering the fprobe, like;

 fprobe.flags = FPROBE_FL_KPROBE_SHARED;

 register_fprobe(&fprobe, "func*", NULL);

This will protect your common callback from the nested call.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735293127.1084943.15687374237275817599.stgit@devnote2
2022-03-17 20:17:02 -07:00
..
blktrace.c blktrace: switch trace spinlock to a raw spinlock 2021-12-20 13:50:14 -07:00
bpf_trace.c bpf: Add bpf_copy_from_user_task() helper 2022-01-24 19:59:27 -08:00
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 x86/ftrace: Make function graph use ftrace directly 2021-10-20 23:44:43 -04:00
fprobe.c fprobe: Introduce FPROBE_FL_KPROBE_SHARED flag for fprobe 2022-03-17 20:17:02 -07:00
ftrace_internal.h x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up 2020-05-12 18:24:34 -04:00
ftrace.c ftrace: Add ftrace_set_filter_ips function 2022-03-17 20:15:17 -07:00
Kconfig fprobe: Add exit_handler support 2022-03-17 20:16:52 -07:00
kprobe_event_gen_test.c tracing: Add kprobe event command generation test module 2020-01-30 09:46:28 -05:00
Makefile rethook: Add a generic return hook 2022-03-17 20:16:29 -07:00
pid_list.c tracing: Initialize upper and lower vars in pid_list_refill_irq() 2021-10-07 09:56:38 -04:00
pid_list.h tracing: Create a sparse bitmask for pid filtering 2021-10-05 17:38:45 -04:00
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 kernel: trace: preemptirq_delay_test: add cpu affinity 2021-02-02 17:02:07 -05:00
rethook.c rethook: Add a generic return hook 2022-03-17 20:16:29 -07:00
ring_buffer_benchmark.c sched,tracing: Convert to sched_set_fifo() 2020-07-29 11:43:53 +02:00
ring_buffer.c ring-buffer: make use of the helper function kthread_run_on_cpu() 2022-01-15 16:30:23 +02:00
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: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_benchmark.c tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00
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: Fix missing trace_boot_init_histograms kstrdup NULL checks 2021-10-26 09:18:10 -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: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
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 eprobes: Remove redundant event type information 2022-02-25 12:07:01 -05:00
trace_event_perf.c tracing: Show size of requested perf buffer 2021-10-27 12:25:09 -04:00
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: Add ustring operation to filtering string pointers 2022-01-14 03:42:24 -05:00
trace_events_hist.c tracing: Propagate is_signed to expression 2022-01-27 19:15:49 -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 updates for 5.17: 2022-01-16 10:15:32 +02:00
trace_events_trigger.c tracing: Uninline trace_trigger_soft_disabled() partly 2022-02-25 12:07:01 -05:00
trace_events.c tracing: Remove duplicate warnings when calling trace_create_file() 2022-01-13 17:02:42 -05:00
trace_export.c tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00
trace_functions_graph.c tracing: in_irq() cleanup 2021-10-13 18:19:41 -04:00
trace_functions.c ftrace: disable preemption when recursion locked 2021-10-27 11:21:49 -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_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 Tracing updates for 5.17: 2022-01-16 10:15:32 +02:00
trace_mmiotrace.c tracing: Remove definition of DEBUG in trace_mmiotrace.c 2021-02-02 17:02:07 -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_osnoise.c tracing/osnoise: Make osnoise_main to sleep for microseconds 2022-02-25 12:07:01 -05:00
trace_output.c tracing: Account bottom half disabled sections. 2022-01-13 16:23:04 -05:00
trace_output.h ftrace: Add recording of functions that caused recursion 2020-11-06 08:42:26 -05:00
trace_preemptirq.c lockdep: fix order in trace_hardirqs_off_caller() 2020-09-14 10:08:07 +02:00
trace_printk.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -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_probe.c eprobes: Remove redundant event type information 2022-02-25 12:07:01 -05:00
trace_probe.h eprobes: Remove redundant event type information 2022-02-25 12:07:01 -05:00
trace_recursion_record.c tracing: Disable "other" permission bits in the tracefs files 2021-10-08 18:08:43 -04:00
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: Change variable type as bool for clean-up 2021-06-30 09:19:14 -04:00
trace_selftest_dynamic.c ftrace: Mark function tracer test functions noinline/noclone 2018-01-23 15:57:29 -05:00
trace_selftest.c tracing: Fix selftest config check for function graph start up test 2022-02-25 21:05:29 -05:00
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 tracing: Use generic type for comparator function 2019-11-14 13:15:11 -05:00
trace_synth.h tracing: synth events: increase max fields count 2021-09-08 15:29:16 -04:00
trace_syscalls.c tracing: Have syscall trace events use trace_event_buffer_lock_reserve() 2022-01-13 16:23:05 -05:00
trace_uprobe.c Tracing updates for 5.17: 2022-01-16 10:15:32 +02:00
trace.c tracing: Ensure trace buffer is at least 4096 bytes large 2022-02-25 12:07:01 -05:00
trace.h eprobes: Remove redundant event type information 2022-02-25 12:07:01 -05:00
tracing_map.c tracing: Fix a kmemleak false positive in tracing_map 2021-12-01 21:04:34 -05:00
tracing_map.h tracing: Fix some typos in comments 2020-11-10 20:39:40 -05:00