linux/kernel/trace
Ravi Bangoria ba16293dad tracing: Fix kernel crash while using empty filter with perf
Kernel is crashing when user tries to record 'ftrace:function' event
with empty filter:

  # perf record -e ftrace:function --filter="" ls

  # dmesg
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  Oops: 0000 [#1] SMP PTI
  ...
  RIP: 0010:ftrace_profile_set_filter+0x14b/0x2d0
  RSP: 0018:ffffa4a7c0da7d20 EFLAGS: 00010246
  RAX: ffffa4a7c0da7d64 RBX: 0000000000000000 RCX: 0000000000000006
  RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffff8c48ffc968f0
  ...
  Call Trace:
   _perf_ioctl+0x54a/0x6b0
   ? rcu_all_qs+0x5/0x30
  ...

After patch:
  # perf record -e ftrace:function --filter="" ls
  failed to set filter "" on event ftrace:function with 22 (Invalid argument)

Also, if user tries to echo "" > filter, it used to throw an error.
This behavior got changed by commit 80765597bc ("tracing: Rewrite
filter logic to be simpler and faster"). This patch restores the
behavior as a side effect:

Before patch:
  # echo "" > filter
  #

After patch:
  # echo "" > filter
  bash: echo: write error: Invalid argument
  #

Link: http://lkml.kernel.org/r/20180420150758.19787-1-ravi.bangoria@linux.ibm.com

Fixes: 80765597bc ("tracing: Rewrite filter logic to be simpler and faster")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-25 10:27:55 -04:00
..
blktrace.c blktrace: fix trace mutex deadlock 2017-11-27 12:03:58 -07:00
bpf_trace.c bpf: Check attach type at prog load time 2018-03-31 02:14:44 +02:00
ftrace.c ftrace: Drop a VLA in module_exists() 2018-04-06 08:56:48 -04:00
Kconfig tracing: Add inter-event blurb to HIST_TRIGGERS config option 2018-03-10 16:06:05 -05:00
Makefile Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
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
ring_buffer_benchmark.c ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU 2017-08-02 14:23:02 -04:00
ring_buffer.c ring-buffer: Add set/clear_current_oom_origin() during allocations 2018-04-06 08:56:52 -04:00
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
trace_benchmark.c trace: Eliminate cond_resched_rcu_qs() in favor of cond_resched() 2017-12-04 10:28:58 -08:00
trace_benchmark.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_branch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_clock.c tracing: Hide global trace clock from lockdep 2018-04-06 08:56:52 -04:00
trace_entries.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_event_perf.c perf/core: Fix perf_uprobe_init() 2018-04-10 07:33:10 +02:00
trace_events_filter_test.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_events_filter.c tracing: Fix kernel crash while using empty filter with perf 2018-04-25 10:27:55 -04:00
trace_events_hist.c tracing: Uninitialized variable in create_tracing_map_fields() 2018-04-06 08:56:50 -04:00
trace_events_trigger.c tracing: Add variable reference handling to hist triggers 2018-03-10 16:05:58 -05:00
trace_events.c tracing: Make sure the parsed string always terminates with '\0' 2018-01-23 15:57:28 -05:00
trace_export.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions_graph.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions.c tracing: Update stack trace skipping for ORC unwinder 2018-01-23 15:57:00 -05:00
trace_hwlat.c trace: make trace_hwlat timestamp y2038 safe 2017-05-08 17:15:15 -07:00
trace_irqsoff.c tracing: Add support for preempt and irq enable/disable events 2017-10-10 18:58:43 -04:00
trace_kdb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_kprobe.c Merge branch 'perf/urgent' into perf/core 2018-03-29 16:03:48 +02:00
trace_mmiotrace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 sched/debug: Rename task-state printing helpers 2017-10-10 11:43:29 +02:00
trace_output.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_printk.c treewide: Align function definition open/close braces 2018-03-26 11:13:09 +02:00
trace_probe.c tracing: probeevent: Fix to support minus offset from symbol 2018-03-23 12:02:37 -04:00
trace_probe.h Merge branch 'perf/urgent' into perf/core 2018-03-29 16:03:48 +02:00
trace_sched_switch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_sched_wakeup.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
trace_selftest_dynamic.c ftrace: Mark function tracer test functions noinline/noclone 2018-01-23 15:57:29 -05:00
trace_selftest.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_seq.c
trace_stack.c tracing: Have stack trace not record if RCU is not watching 2017-12-14 20:48:22 -05:00
trace_stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_stat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_syscalls.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_uprobe.c Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-15 12:36:31 -07:00
trace.c New features: 2018-04-10 11:27:30 -07:00
trace.h tracing: Rewrite filter logic to be simpler and faster 2018-03-14 12:35:39 -04:00
tracing_map.c tracing: Add per-element variable support to tracing_map 2018-03-10 16:05:53 -05:00
tracing_map.h tracing: Add per-element variable support to tracing_map 2018-03-10 16:05:53 -05:00