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linux/tools/perf/util
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Arnaldo Carvalho de Melo a8f23d8f8a perf trace: Improve messages related to /proc/sys/kernel/perf_event_paranoid 
kernel/events/core.c has:

  /*
   * perf event paranoia level:
   *  -1 - not paranoid at all
   *   0 - disallow raw tracepoint access for unpriv
   *   1 - disallow cpu events for unpriv
   *   2 - disallow kernel profiling for unpriv
   */
  int sysctl_perf_event_paranoid __read_mostly = 1;

So, with the default being 1, a non-root user can trace his stuff:

  [acme@zoo ~]$ cat /proc/sys/kernel/perf_event_paranoid
  1
  [acme@zoo ~]$ yes > /dev/null &
  [1] 15338
  [acme@zoo ~]$ trace -p 15338 | head -5
       0.005 ( 0.005 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.045 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.085 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.125 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.165 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
  [acme@zoo ~]$
  [acme@zoo ~]$ trace --duration 1 sleep 1
    1002.148 (1001.218 ms): nanosleep(rqtp: 0x7fff46c79250                           ) = 0
  [acme@zoo ~]$
  [acme@zoo ~]$ trace -- usleep 1 | tail -5
       0.905 ( 0.002 ms): brk(                                                     ) = 0x1c82000
       0.910 ( 0.003 ms): brk(brk: 0x1ca3000                                       ) = 0x1ca3000
       0.913 ( 0.001 ms): brk(                                                     ) = 0x1ca3000
       0.990 ( 0.059 ms): nanosleep(rqtp: 0x7fffe31a3280                           ) = 0
       0.995 ( 0.000 ms): exit_group(
  [acme@zoo ~]$

But can't do system wide tracing:

  [acme@zoo ~]$ trace
  Error:	Operation not permitted.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 1.
  [acme@zoo ~]$

  [acme@zoo ~]$ trace --cpu 0
  Error:	Operation not permitted.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 1.
  [acme@zoo ~]$

If the paranoid level is >= 2, i.e. turn this perf stuff off for !root users:

  [acme@zoo ~]$ sudo sh -c 'echo 2 > /proc/sys/kernel/perf_event_paranoid'
  [acme@zoo ~]$ cat /proc/sys/kernel/perf_event_paranoid
  2
  [acme@zoo ~]$
  [acme@zoo ~]$ trace usleep 1
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$
  [acme@zoo ~]$ trace
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$
  [acme@zoo ~]$ trace --cpu 1
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$

If the user manages to get what he/she wants, convincing root not
to be paranoid at all...

  [root@zoo ~]# echo -1 > /proc/sys/kernel/perf_event_paranoid
  [root@zoo ~]# cat /proc/sys/kernel/perf_event_paranoid
  -1
  [root@zoo ~]#

  [acme@zoo ~]$ ps -eo user,pid,comm | grep Xorg
  root       729 Xorg
  [acme@zoo ~]$
  [acme@zoo ~]$ trace -a --duration 0.001 -e \!select,ioctl,writev | grep Xorg  | head -5
      23.143 ( 0.003 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
      23.152 ( 0.004 ms): Xorg/729 read(fd: 31, buf: 0x2544af0, count: 4096     ) = 8
      23.161 ( 0.002 ms): Xorg/729 read(fd: 31, buf: 0x2544af0, count: 4096     ) = -1 EAGAIN Resource temporarily unavailable
      23.175 ( 0.002 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
      23.235 ( 0.002 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
  [acme@zoo ~]$

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-di28olfwd28rvkox7v3hqhu1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-17 17:38:29 -03:00
..
include tools/perf: Turn strlcpy() into a __weak function 2013-10-09 08:48:49 +02:00
scripting-engines perf scripting perl: Fix build error on Fedora 12 2013-10-15 08:34:00 -03:00
abspath.c
alias.c perf tools: Use __maybe_used for unused variables 2012-09-11 12:19:15 -03:00
annotate.c perf annotate: Find kcore symbols on other maps 2013-10-14 10:29:20 -03:00
annotate.h perf tools: Separate out GTK codes to libperf-gtk.so 2013-10-09 15:55:25 -03:00
bitmap.c perf tools: Add bitmap_or function into bitmap object 2012-02-13 23:28:10 -02:00
build-id.c perf tools: Add attr->mmap2 support 2013-09-11 10:09:32 -03:00
build-id.h perf tools: Move BUILD_ID_SIZE into build-id object 2012-10-29 11:35:32 -02:00
cache.h tools/perf: Turn strlcpy() into a __weak function 2013-10-09 08:48:49 +02:00
callchain.c perf callchain: Remove unnecessary validation 2013-08-29 15:11:29 -03:00
callchain.h perf callchain: Remove unnecessary validation 2013-08-29 15:11:29 -03:00
cgroup.c perf tools: Use __maybe_used for unused variables 2012-09-11 12:19:15 -03:00
cgroup.h perf tool: Add cgroup support 2011-02-16 13:30:48 +01:00
color.c perf tools: Use scnprintf where applicable 2012-03-14 12:36:19 -03:00
color.h
config.c perf tools: Use __maybe_used for unused variables 2012-09-11 12:19:15 -03:00
cpumap.c perf stat: Add per-core aggregation 2013-03-25 16:13:26 -03:00
cpumap.h perf tools: Rename cpu_map__all() to cpu_map__empty() 2013-07-12 13:45:44 -03:00
ctype.c perf tools: ctype.c only wants util.h 2012-02-13 23:17:40 -02:00
debug.c perf tools: Fix TUI helpline output 2012-12-09 08:46:07 -03:00
debug.h perf evsel: Introduce perf_evsel__open_strerror method 2013-01-24 16:40:09 -03:00
dso.c perf tools: Save failed result of get_srcline() 2013-10-09 16:02:02 -03:00
dso.h perf tools: Save failed result of get_srcline() 2013-10-09 16:02:02 -03:00
dwarf-aux.c perf probe: Fix to find line information for probe list 2013-10-04 15:16:05 -03:00
dwarf-aux.h perf probe: Fix to find line information for probe list 2013-10-04 15:16:05 -03:00
environment.c
event.c perf tools: Add attr->mmap2 support 2013-09-11 10:09:32 -03:00
event.h perf evlist: Fix perf_evlist__mmap_read event overflow 2013-10-11 12:17:40 -03:00
evlist.c perf trace: Improve messages related to /proc/sys/kernel/perf_event_paranoid 2013-10-17 17:38:29 -03:00
evlist.h perf trace: Improve messages related to /proc/sys/kernel/perf_event_paranoid 2013-10-17 17:38:29 -03:00
evsel.c perf evlist: Fix perf_evlist__mmap_read event overflow 2013-10-11 12:17:40 -03:00
evsel.h tools/perf/stat: Add perf stat --transaction 2013-10-04 10:06:07 +02:00
exec_cmd.c perf tools: Makefile: Remove various and sundry cruft 2011-02-18 07:43:06 -02:00
exec_cmd.h
generate-cmdlist.sh tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
header.c perf session: Fix infinite loop on invalid perf.data file 2013-10-04 15:17:46 -03:00
header.h perf header: Recognize version number for perf data file 2013-07-17 17:04:00 -03:00
help.c perf tools: Use __maybe_used for unused variables 2012-09-11 12:19:15 -03:00
help.h
hist.c perf annotate: Factor out get/free_srcline() 2013-10-09 15:59:39 -03:00
hist.h perf tools: Separate out GTK codes to libperf-gtk.so 2013-10-09 15:55:25 -03:00
hweight.c
intlist.c perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
intlist.h perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
levenshtein.c
levenshtein.h
machine.c perf symbols: Make a separate function to parse /proc/modules 2013-10-11 12:17:57 -03:00
machine.h perf machine: Add method to loop over threads and invoke handler 2013-10-11 12:17:51 -03:00
map.c perf annotate: Another fix for annotate_browser__callq() 2013-10-14 12:21:18 -03:00
map.h perf annotate: Another fix for annotate_browser__callq() 2013-10-14 12:21:18 -03:00
pager.c perf tools: Fix pager on minimal-install embedded systems 2012-05-30 15:10:39 -03:00
parse-events.c perf list: Skip unsupported events 2013-09-02 14:58:21 -03:00
parse-events.h perf parse events: Demystify memory allocations 2013-07-12 13:52:05 -03:00
parse-events.l perf tools: Move start conditions to start of the flex file 2013-10-11 12:17:31 -03:00
parse-events.y perf parse events: Demystify memory allocations 2013-07-12 13:52:05 -03:00
parse-options.c perf tools: Long option completion support for each subcommands 2012-10-02 18:36:44 -03:00
parse-options.h perf tools: Long option completion support for each subcommands 2012-10-02 18:36:44 -03:00
path.c tools/perf: Turn strlcpy() into a __weak function 2013-10-09 08:48:49 +02:00
perf_regs.h tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
PERF-VERSION-GEN perf tools: Align perf version output to other build messages 2013-10-11 12:18:10 -03:00
pmu.c tools/perf/stat: Add perf stat --transaction 2013-10-04 10:06:07 +02:00
pmu.h tools/perf/stat: Add perf stat --transaction 2013-10-04 10:06:07 +02:00
pmu.l perf tools: Add perf pmu object to access pmu format definition 2012-03-16 14:29:35 -03:00
pmu.y perf tools: Fix build with bison 2.3 and older. 2013-02-14 16:12:34 -03:00
probe-event.c tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
probe-event.h perf probe: Provide perf interface for uprobes 2012-05-11 13:58:17 -03:00
probe-finder.c perf probe: Fix to find line information for probe list 2013-10-04 15:16:05 -03:00
probe-finder.h tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
pstack.c perf tools: Stop using 'self' in pstack 2012-11-14 16:50:38 -03:00
pstack.h
python-ext-sources perf tools: Introduce tools/lib/lk library 2013-03-15 13:06:00 -03:00
python.c perf tools: Adding throttle event data struct support 2013-10-09 11:39:18 -03:00
quote.c
quote.h
rblist.c perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
rblist.h perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
record.c perf tools: Add support for PERF_SAMPLE_IDENTIFIER 2013-08-29 16:09:31 -03:00
run-command.c
run-command.h
session.c perf tools: Adding throttle event data struct support 2013-10-09 11:39:18 -03:00
session.h perf session: Check for SIGINT in more loops 2013-09-19 11:32:17 -03:00
setup.py perf tools: Merge all *CFLAGS* make variable into CFLAGS 2013-05-30 16:12:03 +03:00
sigchain.c
sigchain.h
sort.c perf tools: Fix srcline sort key behavior 2013-10-09 17:26:42 -03:00
sort.h tools/perf: Add support for record transaction flags 2013-10-04 10:06:12 +02:00
srcline.c perf tools: Fix old GCC build error in 'get_srcline' 2013-10-14 10:28:52 -03:00
stat.c perf stats: Add max and min stats 2013-08-07 17:35:26 -03:00
stat.h perf stats: Add max and min stats 2013-08-07 17:35:26 -03:00
strbuf.c perf tools: Fix strbuf_addf() when the buffer needs to grow 2012-10-30 10:32:56 -02:00
strbuf.h
strfilter.c perf: Fix missing strndup declaration 2011-03-04 01:17:18 +01:00
strfilter.h perf tools: Add strfilter for general purpose string filter 2011-01-28 09:19:38 -02:00
string.c perf tools: Default to cpu// for events v5 2013-07-12 13:53:52 -03:00
strlist.c perf probe: Fix segfault 2013-03-13 17:00:33 -03:00
strlist.h perf tools: Stop using 'self' in strlist 2013-01-25 12:49:28 -03:00
svghelper.c perf timechart: Fix black idle boxes in the title 2011-02-28 08:56:14 +01:00
svghelper.h
symbol-elf.c perf symbols: Fix a mmap and munmap mismatched bug 2013-10-14 12:21:23 -03:00
symbol-minimal.c perf buildid-cache: Add ability to add kcore to the cache 2013-10-14 12:20:38 -03:00
symbol.c perf symbols: Fix a memory leak due to symbol__delete not being used 2013-10-14 12:21:20 -03:00
symbol.h perf buildid-cache: Add ability to add kcore to the cache 2013-10-14 12:20:38 -03:00
sysfs.c perf tools: Fix possible (unlikely) buffer overflow 2013-01-24 16:40:18 -03:00
sysfs.h perf tools: Add sysfs mountpoint interface 2012-02-13 23:27:15 -02:00
target.c perf tools: Replace mempcpy with memcpy 2012-09-05 19:35:21 -03:00
target.h perf target: Add uses_mmap field 2012-05-17 12:32:54 -03:00
thread_map.c perf tools: fix thread_map__new_by_pid_str() memory leak in error path 2012-05-25 11:40:59 -03:00
thread_map.h perf evlist: Add thread_map__nr() helper 2013-03-15 13:06:02 -03:00
thread.c perf tools: Add pid to struct thread 2013-08-27 11:05:53 -03:00
thread.h perf tools: Add pid to struct thread 2013-08-27 11:05:53 -03:00
tool.h perf tools: Add attr->mmap2 support 2013-09-11 10:09:32 -03:00
top.c perf top: Fix percent output when no samples collected 2013-05-28 16:23:59 +03:00
top.h perf top: move CONSOLE_CLEAR to header file 2013-08-07 17:35:26 -03:00
trace-event-info.c perf util: No need to call read_trace_init() in tracing_data_header() 2013-07-12 13:52:31 -03:00
trace-event-parse.c perf tools: Remove unused trace-event-* code 2013-10-09 11:15:28 -03:00
trace-event-read.c perf util: Parse header_page to get proper long size 2013-07-12 13:52:24 -03:00
trace-event-scripting.c perf script: Fix named threads support 2013-07-22 11:55:53 -03:00
trace-event.h perf tools: Remove unused trace-event-* code 2013-10-09 11:15:28 -03:00
types.h perf tools: Add union u64_swap type for swapping u64 data 2012-05-22 12:50:25 -03:00
unwind.c perf tools: Remove filter parameter of thread__find_addr_map() 2013-08-12 10:31:12 -03:00
unwind.h tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
usage.c perf target: Introduce perf_target__parse_uid() 2012-05-07 16:46:48 -03:00
util.c perf tools: Introduce filename__read_int helper 2013-10-17 16:33:43 -03:00
util.h perf tools: Introduce filename__read_int helper 2013-10-17 16:33:43 -03:00
values.c perf tools: Fix a memory leak on perf_read_values_destroy 2011-12-20 13:41:34 -02:00
values.h
vdso.c perf symbols: Fix vdso list searching 2013-07-08 17:59:07 -03:00
vdso.h perf tools: Back [vdso] DSO with real data 2012-09-11 12:08:30 -03:00
wrapper.c perf tools: Use __maybe_used for unused variables 2012-09-11 12:19:15 -03:00
xyarray.c perf tools: Introduce event selectors 2011-01-03 16:39:04 -02:00
xyarray.h perf tools: Introduce event selectors 2011-01-03 16:39:04 -02:00