IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
Valgrind was complaining:
$ valgrind ./perf list >/dev/null
==11643== Memcheck, a memory error detector
==11643== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==11643== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==11643== Command: ./perf list
==11643==
==11643== Conditional jump or move depends on uninitialised value(s)
==11643== at 0x4C30620: rindex (vg_replace_strmem.c:199)
==11643== by 0x49DAA9: build_id_cache__origname (build-id.c:198)
==11643== by 0x49E1C7: build_id_cache__valid_id (build-id.c:222)
==11643== by 0x49E1C7: build_id_cache__list_all (build-id.c:507)
==11643== by 0x4B9C8F: print_sdt_events (parse-events.c:2067)
==11643== by 0x4BB0B3: print_events (parse-events.c:2313)
==11643== by 0x439501: cmd_list (builtin-list.c:53)
==11643== by 0x497150: run_builtin (perf.c:359)
==11643== by 0x428CE0: handle_internal_command (perf.c:421)
==11643== by 0x428CE0: run_argv (perf.c:467)
==11643== by 0x428CE0: main (perf.c:614)
[...]
Additionally, a zero length result from readlink() is not very interesting.
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170322130624.21881-3-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Valgrind was complaining:
==2633== Syscall param open(filename) points to unaddressable byte(s)
==2633== at 0x5281CC0: __open_nocancel (syscall-template.S:84)
==2633== by 0x537D38: open (fcntl2.h:53)
==2633== by 0x537D38: get_sdt_note_list (symbol-elf.c:2017)
==2633== by 0x5396FD: probe_cache__scan_sdt (probe-file.c:700)
==2633== by 0x49EA2C: build_id_cache__add_sdt_cache (build-id.c:625)
==2633== by 0x49EA2C: build_id_cache__add_s (build-id.c:697)
==2633== by 0x49EE72: build_id_cache__add_b (build-id.c:717)
==2633== by 0x49EE72: dso__cache_build_id (build-id.c:782)
==2633== by 0x49F190: __dsos__cache_build_ids (build-id.c:793)
==2633== by 0x49F190: machine__cache_build_ids (build-id.c:801)
==2633== by 0x49F190: perf_session__cache_build_ids (build-id.c:815)
==2633== by 0x4CD4F2: write_build_id (header.c:165)
==2633== by 0x4D26F7: do_write_feat (header.c:2296)
==2633== by 0x4D26F7: perf_header__adds_write (header.c:2335)
==2633== by 0x4D26F7: perf_session__write_header (header.c:2414)
==2633== by 0x43B324: __cmd_record (builtin-record.c:1154)
==2633== by 0x43B324: cmd_record (builtin-record.c:1839)
==2633== by 0x455A07: __cmd_record (builtin-kmem.c:1868)
==2633== by 0x455A07: cmd_kmem (builtin-kmem.c:1944)
==2633== by 0x497150: run_builtin (perf.c:359)
==2633== by 0x428CE0: handle_internal_command (perf.c:421)
==2633== by 0x428CE0: run_argv (perf.c:467)
==2633== by 0x428CE0: main (perf.c:614)
==2633== Address 0x0 is not stack'd, malloc'd or (recently) free'd
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Link: http://lkml.kernel.org/r/20170322130624.21881-2-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support @BUILDID or @FILE suffix for SDT events. This allows perf to add
probes on SDTs/pre-cached events on given FILE or the file which has
given BUILDID (also, this complements BUILDID.)
For example, both gcc and libstdc++ has same SDTs as below. If you
would like to add a probe on sdt_libstdcxx:catch on gcc, you can do as
below.
----
# perf list sdt | tail -n 6
sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
# perf probe -a %sdt_libstdcxx:catch@0cc
Added new event:
sdt_libstdcxx:catch (on %catch in /usr/bin/gcc)
You can now use it in all perf tools, such as:
perf record -e sdt_libstdcxx:catch -aR sleep 1
----
Committer note:
Doing the full sequence of steps to get the results above:
With a clean build-id cache:
[root@jouet ~]# rm -rf ~/.debug/
[root@jouet ~]# perf list sdt
List of pre-defined events (to be used in -e):
[root@jouet ~]#
No events whatsoever, then, we can add all events in gcc to the build-id
cache, doing a --add + --dry-run:
[root@jouet ~]# perf probe --dry-run --cache -x /usr/bin/gcc --add %sdt_libstdcxx:\*
Added new events:
sdt_libstdcxx:throw (on %* in /usr/bin/gcc)
sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc)
sdt_libstdcxx:catch (on %* in /usr/bin/gcc)
You can now use it in all perf tools, such as:
perf record -e sdt_libstdcxx:catch -aR sleep 1
[root@jouet ~]#
It really didn't add any events, it just cached them:
[root@jouet ~]# perf probe -l
[root@jouet ~]#
We can see that it was cached as:
[root@jouet ~]# ls -la ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/
total 976
drwxr-xr-x. 2 root root 4096 Jul 13 21:47 .
drwxr-xr-x. 3 root root 4096 Jul 13 21:47 ..
-rwxr-xr-x. 4 root root 985912 Jun 22 18:52 elf
-rw-r--r--. 1 root root 303 Jul 13 21:47 probes
[root@jouet ~]# file ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf
/root/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/elf: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2, stripped
[root@jouet ~]# cat ~/.debug/usr/bin/gcc/9a0730e2bcc6d2a2003d21ac46807e8ee6bcb7c2/probes
%sdt_libstdcxx:throw=throw
p:sdt_libstdcxx/throw /usr/bin/gcc:0x71ffd
%sdt_libstdcxx:rethrow=rethrow
p:sdt_libstdcxx/rethrow /usr/bin/gcc:0x720b8
%sdt_libstdcxx:catch=catch
p:sdt_libstdcxx/catch /usr/bin/gcc:0x7307f
%sdt_libgcc:unwind=unwind
p:sdt_libgcc/unwind /usr/bin/gcc:0x7eec0
#sdt_libstdcxx:*=%*
[root@jouet ~]#
Ok, now we can use 'perf probe' to refer to those cached entries as:
Humm, nope, doing as above we end up with:
[root@jouet ~]# perf probe -a %sdt_libstdcxx:catch
Semantic error :* is bad for event name -it must follow C symbol-naming rule.
Error: Failed to add events.
[root@jouet ~]#
But it worked at some point, lets try not using --dry-run:
Resetting everything:
# rm -rf ~/.debug/
# perf probe -d *:*
# perf probe -l
# perf list sdt
List of pre-defined events (to be used in -e):
#
Ok, now it cached everything, even things we haven't asked it to
(sdt_libgcc:unwind):
[root@jouet ~]# perf probe -x /usr/bin/gcc --add %sdt_libstdcxx:\*
Added new events:
sdt_libstdcxx:throw (on %* in /usr/bin/gcc)
sdt_libstdcxx:rethrow (on %* in /usr/bin/gcc)
sdt_libstdcxx:catch (on %* in /usr/bin/gcc)
You can now use it in all perf tools, such as:
perf record -e sdt_libstdcxx:catch -aR sleep 1
[root@jouet ~]# perf list sdt
List of pre-defined events (to be used in -e):
sdt_libgcc:unwind [SDT event]
sdt_libstdcxx:catch [SDT event]
sdt_libstdcxx:rethrow [SDT event]
sdt_libstdcxx:throw [SDT event]
[root@jouet ~]#
And we have the events in place:
[root@jouet ~]# perf probe -l
sdt_libstdcxx:catch (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc)
sdt_libstdcxx:rethrow (on d_print_subexpr+280@libsupc++/cp-demangle.c in /usr/bin/gcc)
sdt_libstdcxx:throw (on d_print_subexpr+93@libsupc++/cp-demangle.c in /usr/bin/gcc)
[root@jouet ~]#
And trying to use them at least has 'perf trace --event sdt*:*' working.
Then, if we try to add the ones in libstdc++:
[root@jouet ~]# perf probe -x /usr/lib64/libstdc++.so.6 -a %sdt_libstdcxx:\*
Error: event "catch" already exists.
Hint: Remove existing event by 'perf probe -d'
or force duplicates by 'perf probe -f'
or set 'force=yes' in BPF source.
Error: Failed to add events.
[root@jouet ~]#
Doesn't work, dups, but at least this served to, unbeknownst to the user, add
the SDT probes in /usr/lib64/libstdc++.so.6!
[root@jouet ~]# perf list sdt
List of pre-defined events (to be used in -e):
sdt_libgcc:unwind [SDT event]
sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
sdt_libstdcxx:rethrow@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
sdt_libstdcxx:throw@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
[root@jouet ~]#
Now we should be able to get to the original cset comment, if we remove all
SDTs events in place, not from the cache, from the kernel, where it was set up as:
[root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/
total 0
drwxr-xr-x. 5 root root 0 Jul 13 22:00 .
drwxr-xr-x. 80 root root 0 Jul 13 21:56 ..
drwxr-xr-x. 2 root root 0 Jul 13 22:00 catch
-rw-r--r--. 1 root root 0 Jul 13 22:00 enable
-rw-r--r--. 1 root root 0 Jul 13 22:00 filter
drwxr-xr-x. 2 root root 0 Jul 13 22:00 rethrow
drwxr-xr-x. 2 root root 0 Jul 13 22:00 throw
[root@jouet ~]#
[root@jouet ~]# head -2 /sys/kernel/debug/tracing/events/sdt_libstdcxx/throw/format
name: throw
ID: 2059
[root@jouet ~]#
Now to remove it:
[root@jouet ~]# perf probe -d sdt_libstdc*:*
Removed event: sdt_libstdcxx:catch
Removed event: sdt_libstdcxx:rethrow
Removed event: sdt_libstdcxx:throw
[root@jouet ~]#
Which caused:
[root@jouet ~]# ls -la /sys/kernel/debug/tracing/events/sdt_libstdcxx/
ls: cannot access '/sys/kernel/debug/tracing/events/sdt_libstdcxx/': No such file or directory
[root@jouet ~]#
Ok, now we can do:
[root@jouet ~]# perf list sdt_libstdcxx:catch
List of pre-defined events (to be used in -e):
sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
[root@jouet ~]#
So, these are not really 'pre-defined events', i.e. we can't use them with
'perf record --event':
[root@jouet ~]# perf record --event sdt_libstdcxx:catch*
event syntax error: 'sdt_libstdcxx:catch*'
\___ unknown tracepoint
Error: File /sys/kernel/debug/tracing/events/sdt_libstdcxx/catch* not found.
Hint: Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
<SNIP>
[root@jouet ~]#
To have it really pre-defined we must use perf probe to get its definition from
the cache and set it up in the kernel, creating the tracepoint to _then_ use it
with 'perf record --event':
[root@jouet ~]# perf probe -a sdt_libstdcxx:catch
Semantic error :There is non-digit char in line number.
<SNIP>
Oops, there is another gotcha here, we need that pesky '%' character:
[root@jouet ~]# perf probe -a %sdt_libstdcxx:catch
Added new events:
sdt_libstdcxx:catch (on %catch in /usr/bin/gcc)
sdt_libstdcxx:catch_1 (on %catch in /usr/lib64/libstdc++.so.6.0.22)
You can now use it in all perf tools, such as:
perf record -e sdt_libstdcxx:catch_1 -aR sleep 1
[root@jouet ~]#
But then we added _two_ events, one with the name we expected, the other one
with a _ added, when doing the analysis we need to pay attention to who maps to
who.
And here is where we get to the point of this patch, which is to be able to
disambiguate those definitions for 'catch' in the build-id cache, but first we need
remove those events we just added:
[root@jouet ~]# perf probe -d %sdt_libstdcxx:catch
Oops, that didn't remove anything, we need to _remove_ that % char in this case:
[root@jouet ~]# perf probe -d sdt_libstdcxx:catch
Removed event: sdt_libstdcxx:catch
And we need to remove the other event added, i.e. I forgot to add a * at the end:
[root@jouet ~]# perf probe -d sdt_libstdcxx:catch*
Removed event: sdt_libstdcxx:catch_1
[root@jouet ~]#
Ok, disambiguating it using what is in this patch:
[root@jouet ~]# perf list sdt_libstdcxx:catch
List of pre-defined events (to be used in -e):
sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
[root@jouet ~]#
[root@jouet ~]# perf probe -a %sdt_libstdcxx:catch@9a07
Added new event:
sdt_libstdcxx:catch (on %catch in /usr/bin/gcc)
You can now use it in all perf tools, such as:
perf record -e sdt_libstdcxx:catch -aR sleep 1
[root@jouet ~]# perf probe -l
sdt_libstdcxx:catch (on execute_cfa_program+1551@../../../libgcc/unwind-dw2.c in /usr/bin/gcc)
[root@jouet ~]#
Yeah, it works! But we need to try and simplify this :-)
Update: Some aspects of this simplification take place in the following
patches.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831793746.17065.13065062753978236612.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make "perf probe --cache --list" show only available cached events by
checking build-id validity.
E.g. without this patch:
----
$ ./perf probe --cache --add oldevent=cmd_probe
$ make #(to update ./perf)
$ ./perf probe --cache --add newevent=cmd_probe
$ ./perf probe --cache --list
/home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
probe_perf:newevent=cmd_probe
/home/mhiramat/ksrc/linux/tools/perf/perf (c2e44d614e33e1
probe_perf:oldevent=cmd_probe
----
It shows both of old and new events but user can not use old one.
With this;
----
$ ./perf probe --cache -l
/home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
probe_perf:newevent=cmd_probe
----
This shows only new events which are on the existing binary.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831789417.17065.17896487479879669610.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf buildid-cache --add <binary> scans given binary and add
the SDT events to probe cache. "sdt_" prefix is appended for
all SDT providers to avoid event-name clash with other pre-defined
events. It is possible to use the cached SDT events as other cached
events, via perf probe --add "sdt_<provider>:<event>=<event>".
e.g.
----
# perf buildid-cache --add /lib/libc-2.17.so
# perf probe --cache --list | head -n 5
/usr/lib/libc-2.17.so (a6fb821bdf53660eb2c29f778757aef294d3d392):
sdt_libc:setjmp=setjmp
sdt_libc:longjmp=longjmp
sdt_libc:longjmp_target=longjmp_target
sdt_libc:memory_heap_new=memory_heap_new
# perf probe -x /usr/lib/libc-2.17.so \
-a sdt_libc:memory_heap_new=memory_heap_new
Added new event:
sdt_libc:memory_heap_new (on memory_heap_new
in /usr/lib/libc-2.17.so)
You can now use it in all perf tools, such as:
perf record -e sdt_libc:memory_heap_new -aR sleep 1
# perf probe -l
sdt_libc:memory_heap_new (on new_heap+183 in /usr/lib/libc-2.17.so)
----
Note that SDT event entries in probe-cache file is somewhat different
from normal cached events. Normal one starts with "#", but SDTs are
starting with "%".
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736025058.27797.13043265488541434502.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
build_id_cache__kallsyms_path() accepts a string buffer but also allocs
a buffer using asnprintf. Unfortunately, the its only user passes it a
stack-allocated buffer. Freeing it causes crashes like this:
$ perf script
*** Error in `/home/wangnan/perf': free(): invalid pointer: 0x00007fffffff9630 ***
======= Backtrace: =========
lib64/libc.so.6(+0x6eeef)[0x7ffff5dbaeef]
lib64/libc.so.6(+0x78cae)[0x7ffff5dc4cae]
lib64/libc.so.6(+0x79987)[0x7ffff5dc5987]
/home/w00229757/perf(build_id_cache__kallsyms_path+0x6b)[0x49681b]
/home/w00229757/perf[0x4bdd40]
/home/w00229757/perf(dso__load+0xa3a)[0x4c048a]
/home/w00229757/perf(map__load+0x6f)[0x4d561f]
/home/w00229757/perf(thread__find_addr_map+0x235)[0x49e935]
/home/w00229757/perf(machine__resolve+0x7d)[0x49ec6d]
/home/w00229757/perf[0x4555a8]
/home/w00229757/perf[0x4d9507]
/home/w00229757/perf[0x4d9e80]
/home/w00229757/perf(ordered_events__flush+0x354)[0x4dd444]
/home/w00229757/perf(perf_session__process_events+0x3d0)[0x4dc140]
/home/w00229757/perf(cmd_script+0x12b0)[0x4592e0]
/home/w00229757/perf[0x4911f1]
/home/w00229757/perf(main+0x68f)[0x4352ef]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7ffff5d6dbd5]
/home/w00229757/perf[0x435415]
======= Memory map: ========
This patch simplifies build_id_cache__kallsyms_path(), not even
considering allocating a string buffer, so never frees anything. Its
caller should manage memory allocation.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Fixes: 01412261d9 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid")
Link: http://lkml.kernel.org/r/1465271678-7392-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
write_buildid() increments 'name_len' with intention to take into
account trailing zero byte. However, 'name_len' was already incremented
in machine__write_buildid_table() before. So this leads to
out-of-bounds read in do_write():
$ ./perf record sleep 0
[ perf record: Woken up 1 times to write data ]
=================================================================
==15899==ERROR: AddressSanitizer: global-buffer-overflow on address 0x00000099fc92 at pc 0x7f1aa9c7eab5 bp 0x7fff940f84d0 sp 0x7fff940f7c78
READ of size 19 at 0x00000099fc92 thread T0
#0 0x7f1aa9c7eab4 (/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/libasan.so.2+0x44ab4)
#1 0x649c5b in do_write util/header.c:67
#2 0x649c5b in write_padded util/header.c:82
#3 0x57e8bc in write_buildid util/build-id.c:239
#4 0x57e8bc in machine__write_buildid_table util/build-id.c:278
...
0x00000099fc92 is located 0 bytes to the right of global variable '*.LC99' defined in 'util/symbol.c' (0x99fc80) of size 18
'*.LC99' is ascii string '[kernel.kallsyms]'
...
Shadow bytes around the buggy address:
0x00008012bf80: f9 f9 f9 f9 00 00 00 00 00 00 03 f9 f9 f9 f9 f9
=>0x00008012bf90: 00 00[02]f9 f9 f9 f9 f9 00 00 00 00 00 05 f9 f9
0x00008012bfa0: f9 f9 f9 f9 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461053847-5633-1-git-send-email-aryabinin@virtuozzo.com
[ Remove the off-by one at the origin, to keep len(s) == strlen(s) assumption ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before this patch, if a sample is triggered inside a module not in
/lib/modules/`uname -r`/, even if the module is in buildid-cache, 'perf
report' will still be unable to find the correct symbol. For example:
# rm -rf ~/.debug/
# perf buildid-cache -a ./mymodule.ko
# perf probe -m ./mymodule.ko -a get_mymodule_val
Added new event:
probe:get_mymodule_val (on get_mymodule_val in mymodule)
You can now use it in all perf tools, such as:
perf record -e probe:get_mymodule_val -aR sleep 1
# perf record -e probe:get_mymodule_val cat /proc/mymodule
mymodule:3
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.011 MB perf.data (1 samples) ]
# perf report --stdio
[SNIP]
#
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
100.00% cat [mymodule] [k] 0x0000000000000001
# perf report -vvvv --stdio
dso__load_sym: adjusting symbol: st_value: 0 sh_addr: 0 sh_offset: 0x70
symbol__new: get_mymodule_val 0x70-0x8a
[SNIP]
This is caused by dso__load() -> dso__load_sym(). In dso__load(), kmod
is true only when its file is found in some well know directories. All
files loaded from buildid-cache are treated as user programs. Following
dso__load_sym() set map->pgoff incorrectly.
This patch gives kernel modules in buildid-cache a chance to adjust
value of kmod. After dso__load() get the type of symbols, if it is
buildid, check the last 3 chars of original filename against '.ko', and
adjust the value of kmod if the file is a kernel module.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kirill Smelkov <kirr@nexedi.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1454680939-24963-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is a nasty confusion that, for kernel module, dso->kernel is not
necessary to be DSO_TYPE_KERNEL or DSO_TYPE_GUEST_KERNEL. These two
enums are for vmlinux. See thread [1]. We tried to fix this part but it
is costy.
Code machine__write_buildid_table() is another unfortunate function fall
into this trap that, when issuing buildid event for a kernel module,
cpumode it gives to the event is PERF_RECORD_MISC_USER, not
PERF_RECORD_MISC_KERNEL.
However, even with this bug, most of the time it doesn't causes real
problem. I find this issue when trying to use a perf before commit
3d39ac5386 ("perf machine: No need to have two DSOs lists") to parse a
perf.data generated by newest perf.
[1] https://lkml.org/lkml/2015/9/21/908
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1454089251-203152-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The --kernel option of perf buildid-list tool should show the running
kernel buildid. The functionality has been lost during other changes of
the related code.
The build_id__sprintf() function should return length of the build-id
string, but it was the length of the build-id raw data instead. Due to
that, some return value checking caused that the final string was not
printed out.
With this patch the build_id__sprintf() returns the correct value, so
the --kernel option works again.
Before:
# perf buildid-list --kernel
#
After:
# perf buildid-list --kernel
972c1edab5bdc06cc224af45d510af662a3c6972
#
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
LPU-Reference: 1448632089.24573.114.camel@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In addition to using refcounts for the struct thread lifetime
management, we need to protect access to machine->threads from
concurrent access.
That happens in 'perf top', where a thread processes events, inserting
and deleting entries from that rb_tree while another thread decays
hist_entries, that end up dropping references and ultimately deleting
threads from the rb_tree and releasing its resources when no further
hist_entry (or other data structures, like in 'perf sched') references
it.
So the rule is the same for refcounts + protected trees in the kernel,
get the tree lock, find object, bump the refcount, drop the tree lock,
return, use object, drop the refcount if no more use of it is needed,
keep it if storing it in some other data structure, drop when releasing
that data structure.
I.e. pair "t = machine__find(new)_thread()" with a "thread__put(t)", and
"perf_event__preprocess_sample(&al)" with "addr_location__put(&al)".
The addr_location__put() one is because as we return references to
several data structures, we may end up adding more reference counting
for the other data structures and then we'll drop it at
addr_location__put() time.
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-bs9rt4n0jw3hi9f3zxyy3xln@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
commit: f3b623b849 ("perf tools: Reference count struct thread")
appends every thread->node to dead_threads in machine__remove_thread()
and list_del_init() this node in thread__put().
perf_event__exit_del_thread() releases thread wihout using
machine__remove_thread(), and causes a NULL pointer crash when
list_del_init(&thread->node) is called. Fix this by using
machine_remove_thread() instead of using thread__put() directly.
This problem can be reproduced as following:
$ perf record ls
$ perf buildid-list --with-hits
[ 3874.195070] perf[1018]: segfault at 0 ip 00000000004b0b15 sp
00007ffc35b44780 error 6 in perf[400000+166000]
Segmentation fault
After this patch:
$ perf record ls
$ perf buildid-list --with-hits
bc23e7c3281e542650ba4324421d6acf78f4c23e /proc/kcore
643324cb0e969f30c56d660f167f84a150845511 [vdso]
0000000000000000000000000000000000000000 /bin/busybox
...
Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428658500-6483-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
const char *name, bool is_kallsyms, bool is_vdso)
{
...
if (access(filename, F_OK)) {
^--------------------------------------------------------- [1]
if (is_kallsyms) {
if (copyfile("/proc/kallsyms", filename))
goto out_free;
} else if (link(realname, filename) && copyfile(name, filename))
^-----------------------------^------------- [2]
\------------ [3]
goto out_free;
}
...
When multiple instances of perf record get to [1] at more or less same time and
run access() one or more may get failure because the file does not exist yet
(since the first instance did not have chance to link it yet).
At this point the race moves to link() at [2] where first thread to get
there links file and goes on but second one gets -EEXIST so it runs
copyfile [3] which truncates the file.
reproducer:
rm -rf /root/.debug
for cpu in $(awk '/processor/ {print $3}' /proc/cpuinfo); do
perf record -a -v -T -F 1000 -C $cpu \
-o perf-${cpu}.data sleep 5 2> /dev/null &
done
wait
and simply search for empty files by:
find /lib/modules/`uname -r`/kernel/* -size 0
Signed-off-by: Milos Vyletel <milos@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1426847846-11112-1-git-send-email-milos@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add --purge FILE to remove all caches of FILE.
Since the current --remove FILE removes a cache which has
same build-id of given FILE. Since the command takes a
FILE path, it can confuse user who tries to remove cache
about FILE path.
-----
# ./perf buildid-cache -v --add ./perf
Adding 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok
# (update the ./perf binary)
# ./perf buildid-cache -v --remove ./perf
Removing 305bbd1be68f66eca7e2d78db294653031edfa79 ./perf: FAIL
./perf wasn't in the cache
-----
Actually, the --remove's FAIL is not shown, it just silently fails.
So, this patch adds --purge FILE action for such usecase.
perf buildid-cache --purge FILE removes all caches which has same FILE
path.
In other words, it removes all caches including old binaries.
-----
# ./perf buildid-cache -v --add ./perf
Adding 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok
# (update the ./perf binary)
# ./perf buildid-cache -v --purge ./perf
Removing 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok
-----
BTW, if you want to purge all the caches, remove ~/.debug/* .
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150227045026.1999.64084.stgit@localhost.localdomain
[ s/dirname/dir_name/g to fix build on fedora14, where dirname is a global ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add new buildid cache if the update target file is not cached.
This can happen when an old binary is replaced by new one after caching
the old one. In this case, user sees his operation just failed.
But it does not look straight, since user just pass the binary "path",
not "build-id".
----
# ./perf buildid-cache --add ./perf
(update ./perf to new binary)
# ./perf buildid-cache --update ./perf
./perf wasn't in the cache
#
----
This patch adds given new binary to cache if the new binary is
not cached. So we'll not see the above error.
----
# ./perf buildid-cache --add ./perf
(update ./perf to new binary)
# ./perf buildid-cache --update ./perf
#
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150226065440.23912.1494.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch adds support for the new PERF_RECORD_MMAP2 record type
exposed by the kernel. This is an extended PERF_RECORD_MMAP record.
It adds for each file-backed mapping the device major, minor number and
the inode number and generation.
This triplet uniquely identifies the source of a file-backed mapping. It
can be used to detect identical virtual mappings between processes, for
instance.
The patch will prefer MMAP2 over MMAP.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1377079825-19057-3-git-send-email-eranian@google.com
[ Cope with 314add6 "Change machine__findnew_thread() to set thread pid",
fix 'perf test' regression test entry affected,
use perf_missing_features.mmap2 to fallback to not using .mmap2 in older kernels,
so that new tools can work with kernels where this feature is not present ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
