* [PATCH v4] perf-probe: Support escaped character in parser
@ 2017-12-12 15:05 Masami Hiramatsu
2017-12-12 15:27 ` Arnaldo Carvalho de Melo
2017-12-28 15:32 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
0 siblings, 2 replies; 6+ messages in thread
From: Masami Hiramatsu @ 2017-12-12 15:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: Masami Hiramatsu, bhargavb, linux-kernel, Paul Clarke,
Ravi Bangoria, Thomas Richter, linux-rt-users, linux-perf-users
Support the special characters escaped by '\' in parser.
This allows user to specify versions directly like below.
=====
# ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
Added new event:
probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
You can now use it in all perf tools, such as:
perf record -e probe_libc:malloc_get_state -aR sleep 1
=====
Or, you can use separators in source filename, e.g.
=====
# ./perf probe -x /opt/test/a.out foo+bar.c:3
Semantic error :There is non-digit character in offset.
Error: Command Parse Error.
=====
Usually "+" in source file cause parser error, but
=====
# ./perf probe -x /opt/test/a.out foo\\+bar.c:4
Added new event:
probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
You can now use it in all perf tools, such as:
perf record -e probe_a:main -aR sleep 1
=====
escaped "\+" allows you to specify that.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
---
Changes in v2:
- Add a description and samples in Documentation/perf-probe.txt
Changes in v3:
- Update for new series.
Changes in v4:
- Fix a build error (Thanks for Arnaldo!)
This time, I ensured that I ran "make build-test" and it passed.
---
tools/perf/Documentation/perf-probe.txt | 16 +++++++++
tools/perf/util/probe-event.c | 58 +++++++++++++++++++------------
2 files changed, 51 insertions(+), 23 deletions(-)
diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index f96382692f42..b6866a05edd2 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -182,6 +182,14 @@ Note that before using the SDT event, the target binary (on which SDT events are
For details of the SDT, see below.
https://sourceware.org/gdb/onlinedocs/gdb/Static-Probe-Points.html
+ESCAPED CHARACTER
+-----------------
+
+In the probe syntax, '=', '@', '+', ':' and ';' are treated as a special character. You can use a backslash ('\') to escape the special characters.
+This is useful if you need to probe on a specific versioned symbols, like @GLIBC_... suffixes, or also you need to specify a source file which includes the special characters.
+Note that usually single backslash is consumed by shell, so you might need to pass double backslash (\\) or wrapping with single quotes (\'AAA\@BBB').
+See EXAMPLES how it is used.
+
PROBE ARGUMENT
--------------
Each probe argument follows below syntax.
@@ -277,6 +285,14 @@ Add a USDT probe to a target process running in a different mount namespace
./perf probe --target-ns <target pid> -x /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-0.b13.el7_3.x86_64/jre/lib/amd64/server/libjvm.so %sdt_hotspot:thread__sleep__end
+Add a probe on specific versioned symbol by backslash escape
+
+ ./perf probe -x /lib64/libc-2.25.so 'malloc_get_state\@GLIBC_2.2.5'
+
+Add a probe in a source file using special characters by backslash escape
+
+ ./perf probe -x /opt/test/a.out 'foo\+bar.c:4'
+
SEE ALSO
--------
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0d6c66d51939..e1dbc9821617 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1325,27 +1325,30 @@ static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
{
char *ptr;
- ptr = strchr(*arg, ':');
+ ptr = strpbrk_esc(*arg, ":");
if (ptr) {
*ptr = '\0';
if (!pev->sdt && !is_c_func_name(*arg))
goto ng_name;
- pev->group = strdup(*arg);
+ pev->group = strdup_esc(*arg);
if (!pev->group)
return -ENOMEM;
*arg = ptr + 1;
} else
pev->group = NULL;
- if (!pev->sdt && !is_c_func_name(*arg)) {
+
+ pev->event = strdup_esc(*arg);
+ if (pev->event == NULL)
+ return -ENOMEM;
+
+ if (!pev->sdt && !is_c_func_name(pev->event)) {
+ zfree(&pev->event);
ng_name:
+ zfree(&pev->group);
semantic_error("%s is bad for event name -it must "
"follow C symbol-naming rule.\n", *arg);
return -EINVAL;
}
- pev->event = strdup(*arg);
- if (pev->event == NULL)
- return -ENOMEM;
-
return 0;
}
@@ -1373,7 +1376,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
arg++;
}
- ptr = strpbrk(arg, ";=@+%");
+ ptr = strpbrk_esc(arg, ";=@+%");
if (pev->sdt) {
if (ptr) {
if (*ptr != '@') {
@@ -1387,7 +1390,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
pev->target = build_id_cache__origname(tmp);
free(tmp);
} else
- pev->target = strdup(ptr + 1);
+ pev->target = strdup_esc(ptr + 1);
if (!pev->target)
return -ENOMEM;
*ptr = '\0';
@@ -1421,13 +1424,14 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
*
* Otherwise, we consider arg to be a function specification.
*/
- if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) {
+ if (!strpbrk_esc(arg, "+@%")) {
+ ptr = strpbrk_esc(arg, ";:");
/* This is a file spec if it includes a '.' before ; or : */
- if (memchr(arg, '.', ptr - arg))
+ if (ptr && memchr(arg, '.', ptr - arg))
file_spec = true;
}
- ptr = strpbrk(arg, ";:+@%");
+ ptr = strpbrk_esc(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
@@ -1436,7 +1440,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
if (arg[0] == '\0')
tmp = NULL;
else {
- tmp = strdup(arg);
+ tmp = strdup_esc(arg);
if (tmp == NULL)
return -ENOMEM;
}
@@ -1469,12 +1473,12 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
arg = ptr;
c = nc;
if (c == ';') { /* Lazy pattern must be the last part */
- pp->lazy_line = strdup(arg);
+ pp->lazy_line = strdup(arg); /* let leave escapes */
if (pp->lazy_line == NULL)
return -ENOMEM;
break;
}
- ptr = strpbrk(arg, ";:+@%");
+ ptr = strpbrk_esc(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
@@ -1501,7 +1505,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
semantic_error("SRC@SRC is not allowed.\n");
return -EINVAL;
}
- pp->file = strdup(arg);
+ pp->file = strdup_esc(arg);
if (pp->file == NULL)
return -ENOMEM;
break;
@@ -2803,23 +2807,31 @@ static int find_probe_functions(struct map *map, char *name,
struct rb_node *tmp;
const char *norm, *ver;
char *buf = NULL;
+ bool cut_version = true;
if (map__load(map) < 0)
return 0;
+ /* If user gives a version, don't cut off the version from symbols */
+ if (strchr(name, '@'))
+ cut_version = false;
+
map__for_each_symbol(map, sym, tmp) {
norm = arch__normalize_symbol_name(sym->name);
if (!norm)
continue;
- /* We don't care about default symbol or not */
- ver = strchr(norm, '@');
- if (ver) {
- buf = strndup(norm, ver - norm);
- if (!buf)
- return -ENOMEM;
- norm = buf;
+ if (cut_version) {
+ /* We don't care about default symbol or not */
+ ver = strchr(norm, '@');
+ if (ver) {
+ buf = strndup(norm, ver - norm);
+ if (!buf)
+ return -ENOMEM;
+ norm = buf;
+ }
}
+
if (strglobmatch(norm, name)) {
found++;
if (syms && found < probe_conf.max_probes)
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v4] perf-probe: Support escaped character in parser
2017-12-12 15:05 [PATCH v4] perf-probe: Support escaped character in parser Masami Hiramatsu
@ 2017-12-12 15:27 ` Arnaldo Carvalho de Melo
2017-12-13 13:40 ` Masami Hiramatsu
2017-12-28 15:32 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
1 sibling, 1 reply; 6+ messages in thread
From: Arnaldo Carvalho de Melo @ 2017-12-12 15:27 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: bhargavb, linux-kernel, Paul Clarke, Ravi Bangoria,
Thomas Richter, linux-rt-users, linux-perf-users
Em Wed, Dec 13, 2017 at 12:05:12AM +0900, Masami Hiramatsu escreveu:
> Support the special characters escaped by '\' in parser.
> This allows user to specify versions directly like below.
>
> =====
> # ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> Added new event:
> probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe_libc:malloc_get_state -aR sleep 1
>
> =====
>
> Or, you can use separators in source filename, e.g.
>
> =====
> # ./perf probe -x /opt/test/a.out foo+bar.c:3
> Semantic error :There is non-digit character in offset.
> Error: Command Parse Error.
> =====
>
> Usually "+" in source file cause parser error, but
>
> =====
> # ./perf probe -x /opt/test/a.out foo\\+bar.c:4
> Added new event:
> probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe_a:main -aR sleep 1
> =====
>
> escaped "\+" allows you to specify that.
<SNIP>
> Changes in v4:
> - Fix a build error (Thanks for Arnaldo!)
> This time, I ensured that I ran "make build-test" and it passed.
Thanks, testing it I still have that artifact:
---------------------------------------
[root@jouet perf]# perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
Added new event:
probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
You can now use it in all perf tools, such as:
perf record -e probe_libc:malloc_get_state -aR sleep 1
[root@jouet perf]# perf probe -l
Failed to find debug information for address dd38eca7
probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
[root@jouet perf]#
---------------------------------------
I mean the "on 0xdd38eca7" part:
That failed to find debug information part:
[root@jouet perf]# perf probe -vv -l
Add filter: *
Opening /sys/kernel/debug/tracing//kprobe_events write=0
Opening /sys/kernel/debug/tracing//uprobe_events write=0
Parsing probe_events: p:probe_libc/malloc_get_state /usr/lib64/libc-2.25.so:0x00000000dd38eca7
Group:probe_libc Event:malloc_get_state probe:p
try to find information at dd38eca7 in /usr/lib64/libc-2.25.so
Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.25.so.debug
Failed to find debug information for address dd38eca7
Failed to find corresponding probes from debuginfo.
symsrc__init: build id mismatch for /usr/lib/debug/usr/lib64/libc-2.25.so.debug.
Failed to find probe point from both of dwarf and map.
probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
[root@jouet perf]#
Ok, so build-id mismatch, lets see:
[root@jouet perf]# rpm -q glibc glibc-debuginfo
glibc-2.25-10.fc26.x86_64
glibc-2.25-10.fc26.i686
glibc-debuginfo-2.25-12.fc26.x86_64
[root@jouet perf]#
Ok, the debuginfo file is newer than the glibc installed, updating glibc
now...
We could have a more informative message in this case, right? I.e.
something like:
[root@jouet perf]# perf probe -l
There was a build-id mismatch while trying to resolve 0xdd38eca7, please
check your system's debuginfo files for mismatches, e.g. check the
versions for glibc and glibc-debuginfo.
probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
[root@jouet perf]#
- Arnaldo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] perf-probe: Support escaped character in parser
2017-12-12 15:27 ` Arnaldo Carvalho de Melo
@ 2017-12-13 13:40 ` Masami Hiramatsu
2017-12-13 15:42 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 6+ messages in thread
From: Masami Hiramatsu @ 2017-12-13 13:40 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: bhargavb, linux-kernel, Paul Clarke, Ravi Bangoria,
Thomas Richter, linux-rt-users, linux-perf-users
On Tue, 12 Dec 2017 12:27:24 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Em Wed, Dec 13, 2017 at 12:05:12AM +0900, Masami Hiramatsu escreveu:
> > Support the special characters escaped by '\' in parser.
> > This allows user to specify versions directly like below.
> >
> > =====
> > # ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> > Added new event:
> > probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
> >
> > You can now use it in all perf tools, such as:
> >
> > perf record -e probe_libc:malloc_get_state -aR sleep 1
> >
> > =====
> >
> > Or, you can use separators in source filename, e.g.
> >
> > =====
> > # ./perf probe -x /opt/test/a.out foo+bar.c:3
> > Semantic error :There is non-digit character in offset.
> > Error: Command Parse Error.
> > =====
> >
> > Usually "+" in source file cause parser error, but
> >
> > =====
> > # ./perf probe -x /opt/test/a.out foo\\+bar.c:4
> > Added new event:
> > probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
> >
> > You can now use it in all perf tools, such as:
> >
> > perf record -e probe_a:main -aR sleep 1
> > =====
> >
> > escaped "\+" allows you to specify that.
>
> <SNIP>
>
> > Changes in v4:
> > - Fix a build error (Thanks for Arnaldo!)
> > This time, I ensured that I ran "make build-test" and it passed.
>
> Thanks, testing it I still have that artifact:
>
> ---------------------------------------
>
> [root@jouet perf]# perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> Added new event:
> probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe_libc:malloc_get_state -aR sleep 1
>
> [root@jouet perf]# perf probe -l
> Failed to find debug information for address dd38eca7
> probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> [root@jouet perf]#
>
> ---------------------------------------
>
> I mean the "on 0xdd38eca7" part:
>
>
> That failed to find debug information part:
>
> [root@jouet perf]# perf probe -vv -l
> Add filter: *
> Opening /sys/kernel/debug/tracing//kprobe_events write=0
> Opening /sys/kernel/debug/tracing//uprobe_events write=0
> Parsing probe_events: p:probe_libc/malloc_get_state /usr/lib64/libc-2.25.so:0x00000000dd38eca7
> Group:probe_libc Event:malloc_get_state probe:p
> try to find information at dd38eca7 in /usr/lib64/libc-2.25.so
> Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.25.so.debug
> Failed to find debug information for address dd38eca7
> Failed to find corresponding probes from debuginfo.
> symsrc__init: build id mismatch for /usr/lib/debug/usr/lib64/libc-2.25.so.debug.
> Failed to find probe point from both of dwarf and map.
> probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> [root@jouet perf]#
Ah, I got it. So symsrc__init checks debugfile to get symbols,
but failed.
>
> Ok, so build-id mismatch, lets see:
>
> [root@jouet perf]# rpm -q glibc glibc-debuginfo
> glibc-2.25-10.fc26.x86_64
> glibc-2.25-10.fc26.i686
> glibc-debuginfo-2.25-12.fc26.x86_64
> [root@jouet perf]#
>
> Ok, the debuginfo file is newer than the glibc installed, updating glibc
> now...
>
> We could have a more informative message in this case, right? I.e.
> something like:
>
> [root@jouet perf]# perf probe -l
> There was a build-id mismatch while trying to resolve 0xdd38eca7, please
> check your system's debuginfo files for mismatches, e.g. check the
> versions for glibc and glibc-debuginfo.
> probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
OK, I'll try to check how debuginfo is searched in such environment.
Thank you,
> [root@jouet perf]#
>
> - Arnaldo
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] perf-probe: Support escaped character in parser
2017-12-13 13:40 ` Masami Hiramatsu
@ 2017-12-13 15:42 ` Arnaldo Carvalho de Melo
2017-12-16 14:52 ` Masami Hiramatsu
0 siblings, 1 reply; 6+ messages in thread
From: Arnaldo Carvalho de Melo @ 2017-12-13 15:42 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: bhargavb, linux-kernel, Paul Clarke, Ravi Bangoria,
Thomas Richter, linux-rt-users, linux-perf-users
Em Wed, Dec 13, 2017 at 10:40:24PM +0900, Masami Hiramatsu escreveu:
> On Tue, 12 Dec 2017 12:27:24 -0300
> Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> > Em Wed, Dec 13, 2017 at 12:05:12AM +0900, Masami Hiramatsu escreveu:
> > > Support the special characters escaped by '\' in parser.
> > > This allows user to specify versions directly like below.
> > >
> > > =====
> > > # ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> > > Added new event:
> > > probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
> > >
> > > You can now use it in all perf tools, such as:
> > >
> > > perf record -e probe_libc:malloc_get_state -aR sleep 1
> > >
> > > =====
> > >
> > > Or, you can use separators in source filename, e.g.
> > >
> > > =====
> > > # ./perf probe -x /opt/test/a.out foo+bar.c:3
> > > Semantic error :There is non-digit character in offset.
> > > Error: Command Parse Error.
> > > =====
> > >
> > > Usually "+" in source file cause parser error, but
> > >
> > > =====
> > > # ./perf probe -x /opt/test/a.out foo\\+bar.c:4
> > > Added new event:
> > > probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
> > >
> > > You can now use it in all perf tools, such as:
> > >
> > > perf record -e probe_a:main -aR sleep 1
> > > =====
> > >
> > > escaped "\+" allows you to specify that.
> >
> > <SNIP>
> >
> > > Changes in v4:
> > > - Fix a build error (Thanks for Arnaldo!)
> > > This time, I ensured that I ran "make build-test" and it passed.
> >
> > Thanks, testing it I still have that artifact:
> >
> > ---------------------------------------
> >
> > [root@jouet perf]# perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> > Added new event:
> > probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
> >
> > You can now use it in all perf tools, such as:
> >
> > perf record -e probe_libc:malloc_get_state -aR sleep 1
> >
> > [root@jouet perf]# perf probe -l
> > Failed to find debug information for address dd38eca7
> > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> > [root@jouet perf]#
> >
> > ---------------------------------------
> >
> > I mean the "on 0xdd38eca7" part:
> >
> >
> > That failed to find debug information part:
> >
> > [root@jouet perf]# perf probe -vv -l
> > Add filter: *
> > Opening /sys/kernel/debug/tracing//kprobe_events write=0
> > Opening /sys/kernel/debug/tracing//uprobe_events write=0
> > Parsing probe_events: p:probe_libc/malloc_get_state /usr/lib64/libc-2.25.so:0x00000000dd38eca7
> > Group:probe_libc Event:malloc_get_state probe:p
> > try to find information at dd38eca7 in /usr/lib64/libc-2.25.so
> > Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.25.so.debug
> > Failed to find debug information for address dd38eca7
> > Failed to find corresponding probes from debuginfo.
> > symsrc__init: build id mismatch for /usr/lib/debug/usr/lib64/libc-2.25.so.debug.
> > Failed to find probe point from both of dwarf and map.
> > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> > [root@jouet perf]#
>
> Ah, I got it. So symsrc__init checks debugfile to get symbols,
> but failed.
>
> >
> > Ok, so build-id mismatch, lets see:
> >
> > [root@jouet perf]# rpm -q glibc glibc-debuginfo
> > glibc-2.25-10.fc26.x86_64
> > glibc-2.25-10.fc26.i686
> > glibc-debuginfo-2.25-12.fc26.x86_64
> > [root@jouet perf]#
> >
> > Ok, the debuginfo file is newer than the glibc installed, updating glibc
> > now...
> >
> > We could have a more informative message in this case, right? I.e.
> > something like:
> >
> > [root@jouet perf]# perf probe -l
> > There was a build-id mismatch while trying to resolve 0xdd38eca7, please
> > check your system's debuginfo files for mismatches, e.g. check the
> > versions for glibc and glibc-debuginfo.
> > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
>
> OK, I'll try to check how debuginfo is searched in such environment.
So, tools/perf/util/symbol.c, function dso__load(), it will have this
loop:
/*
* Read the build id if possible. This is required for
* DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
*/
if (!dso->has_build_id && is_regular_file(dso->long_name)) {
__symbol__join_symfs(name, PATH_MAX, dso->long_name);
if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0)
dso__set_build_id(dso, build_id);
}
/*
* Iterate over candidate debug images.
* Keep track of "interesting" ones (those which have a symtab, dynsym,
* and/or opd section) for processing.
*/
for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
if (dso__read_binary_type_filename(dso, symtab_type, root_dir, name, PATH_MAX))
-------------------
So the glibc file _has_ a build id, it reads it and then will try to
find a file that has that build id, that 'name' variable will have
the file being tried, which may be, for instance, at:
[acme@jouet ~]$ perf buildid-list -i /lib64/libc-2.25.so
7a4787e7c1263dc25461a7b2f2abd2acaa186102
[acme@jouet ~]$ ls -la /usr/lib/debug/.build-id/7a/4787e7c1263dc25461a7b2f2abd2acaa186102
lrwxrwxrwx. 1 root root 33 Oct 11 09:49 /usr/lib/debug/.build-id/7a/4787e7c1263dc25461a7b2f2abd2acaa186102 -> ../../../../../lib64/libc-2.25.so
[acme@jouet ~]$
etc.
So perhaps we can have a routine that does just that loop and prints the
files it finds with the debuginfo they have to help tell which files
where considered?
But perhaps the message I suggested may be good enough?
- Arnaldo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] perf-probe: Support escaped character in parser
2017-12-13 15:42 ` Arnaldo Carvalho de Melo
@ 2017-12-16 14:52 ` Masami Hiramatsu
0 siblings, 0 replies; 6+ messages in thread
From: Masami Hiramatsu @ 2017-12-16 14:52 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: bhargavb, linux-kernel, Paul Clarke, Ravi Bangoria,
Thomas Richter, linux-rt-users, linux-perf-users
On Wed, 13 Dec 2017 12:42:27 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Em Wed, Dec 13, 2017 at 10:40:24PM +0900, Masami Hiramatsu escreveu:
> > On Tue, 12 Dec 2017 12:27:24 -0300
> > Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> >
> > > Em Wed, Dec 13, 2017 at 12:05:12AM +0900, Masami Hiramatsu escreveu:
> > > > Support the special characters escaped by '\' in parser.
> > > > This allows user to specify versions directly like below.
> > > >
> > > > =====
> > > > # ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> > > > Added new event:
> > > > probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
> > > >
> > > > You can now use it in all perf tools, such as:
> > > >
> > > > perf record -e probe_libc:malloc_get_state -aR sleep 1
> > > >
> > > > =====
> > > >
> > > > Or, you can use separators in source filename, e.g.
> > > >
> > > > =====
> > > > # ./perf probe -x /opt/test/a.out foo+bar.c:3
> > > > Semantic error :There is non-digit character in offset.
> > > > Error: Command Parse Error.
> > > > =====
> > > >
> > > > Usually "+" in source file cause parser error, but
> > > >
> > > > =====
> > > > # ./perf probe -x /opt/test/a.out foo\\+bar.c:4
> > > > Added new event:
> > > > probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
> > > >
> > > > You can now use it in all perf tools, such as:
> > > >
> > > > perf record -e probe_a:main -aR sleep 1
> > > > =====
> > > >
> > > > escaped "\+" allows you to specify that.
> > >
> > > <SNIP>
> > >
> > > > Changes in v4:
> > > > - Fix a build error (Thanks for Arnaldo!)
> > > > This time, I ensured that I ran "make build-test" and it passed.
> > >
> > > Thanks, testing it I still have that artifact:
> > >
> > > ---------------------------------------
> > >
> > > [root@jouet perf]# perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
> > > Added new event:
> > > probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
> > >
> > > You can now use it in all perf tools, such as:
> > >
> > > perf record -e probe_libc:malloc_get_state -aR sleep 1
> > >
> > > [root@jouet perf]# perf probe -l
> > > Failed to find debug information for address dd38eca7
> > > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> > > [root@jouet perf]#
> > >
> > > ---------------------------------------
> > >
> > > I mean the "on 0xdd38eca7" part:
> > >
> > >
> > > That failed to find debug information part:
> > >
> > > [root@jouet perf]# perf probe -vv -l
> > > Add filter: *
> > > Opening /sys/kernel/debug/tracing//kprobe_events write=0
> > > Opening /sys/kernel/debug/tracing//uprobe_events write=0
> > > Parsing probe_events: p:probe_libc/malloc_get_state /usr/lib64/libc-2.25.so:0x00000000dd38eca7
> > > Group:probe_libc Event:malloc_get_state probe:p
> > > try to find information at dd38eca7 in /usr/lib64/libc-2.25.so
> > > Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.25.so.debug
> > > Failed to find debug information for address dd38eca7
> > > Failed to find corresponding probes from debuginfo.
> > > symsrc__init: build id mismatch for /usr/lib/debug/usr/lib64/libc-2.25.so.debug.
> > > Failed to find probe point from both of dwarf and map.
> > > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> > > [root@jouet perf]#
> >
> > Ah, I got it. So symsrc__init checks debugfile to get symbols,
> > but failed.
> >
> > >
> > > Ok, so build-id mismatch, lets see:
> > >
> > > [root@jouet perf]# rpm -q glibc glibc-debuginfo
> > > glibc-2.25-10.fc26.x86_64
> > > glibc-2.25-10.fc26.i686
> > > glibc-debuginfo-2.25-12.fc26.x86_64
> > > [root@jouet perf]#
> > >
> > > Ok, the debuginfo file is newer than the glibc installed, updating glibc
> > > now...
> > >
> > > We could have a more informative message in this case, right? I.e.
> > > something like:
> > >
> > > [root@jouet perf]# perf probe -l
> > > There was a build-id mismatch while trying to resolve 0xdd38eca7, please
> > > check your system's debuginfo files for mismatches, e.g. check the
> > > versions for glibc and glibc-debuginfo.
> > > probe_libc:malloc_get_state (on 0xdd38eca7 in /usr/lib64/libc-2.25.so)
> >
> > OK, I'll try to check how debuginfo is searched in such environment.
>
> So, tools/perf/util/symbol.c, function dso__load(), it will have this
> loop:
>
>
> /*
> * Read the build id if possible. This is required for
> * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
> */
> if (!dso->has_build_id && is_regular_file(dso->long_name)) {
> __symbol__join_symfs(name, PATH_MAX, dso->long_name);
> if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0)
> dso__set_build_id(dso, build_id);
> }
>
> /*
> * Iterate over candidate debug images.
> * Keep track of "interesting" ones (those which have a symtab, dynsym,
> * and/or opd section) for processing.
> */
> for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
>
> if (dso__read_binary_type_filename(dso, symtab_type, root_dir, name, PATH_MAX))
>
>
> -------------------
>
> So the glibc file _has_ a build id, it reads it and then will try to
> find a file that has that build id, that 'name' variable will have
> the file being tried, which may be, for instance, at:
>
> [acme@jouet ~]$ perf buildid-list -i /lib64/libc-2.25.so
> 7a4787e7c1263dc25461a7b2f2abd2acaa186102
> [acme@jouet ~]$ ls -la /usr/lib/debug/.build-id/7a/4787e7c1263dc25461a7b2f2abd2acaa186102
> lrwxrwxrwx. 1 root root 33 Oct 11 09:49 /usr/lib/debug/.build-id/7a/4787e7c1263dc25461a7b2f2abd2acaa186102 -> ../../../../../lib64/libc-2.25.so
> [acme@jouet ~]$
>
> etc.
>
> So perhaps we can have a routine that does just that loop and prints the
> files it finds with the debuginfo they have to help tell which files
> where considered?
Hmm, as far as I can see, this occured in debuginfo__new(),
struct debuginfo *debuginfo__new(const char *path)
{
enum dso_binary_type *type;
char buf[PATH_MAX], nil = '\0';
struct dso *dso;
struct debuginfo *dinfo = NULL;
/* Try to open distro debuginfo files */
dso = dso__new(path);
if (!dso)
goto out;
for (type = distro_dwarf_types;
!dinfo && *type != DSO_BINARY_TYPE__NOT_FOUND;
type++) {
if (dso__read_binary_type_filename(dso, *type, &nil,
buf, PATH_MAX) < 0)
continue;
dinfo = __debuginfo__new(buf);
}
dso__put(dso);
out:
/* if failed to open all distro debuginfo, open given binary */
return dinfo ? : __debuginfo__new(path);
}
And dso__read_binary_type_filename() makes a debuginfo path
from target path but doesn't check build-id. So,
(I still can not reproduce your situation but) I guess,
dso__read_binary_type_filename() returns some path, but
__debuginfo__new() just failed to open it.
Or, __debuginfo_new() opened it but since its buildid is
different, it really failed to find any lines on given address.
>
> But perhaps the message I suggested may be good enough?
Yeah, but this means we need to check the buildid of both
binaries.
Thank you,
>
> - Arnaldo
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip:perf/core] perf probe: Support escaped character in parser
2017-12-12 15:05 [PATCH v4] perf-probe: Support escaped character in parser Masami Hiramatsu
2017-12-12 15:27 ` Arnaldo Carvalho de Melo
@ 2017-12-28 15:32 ` tip-bot for Masami Hiramatsu
1 sibling, 0 replies; 6+ messages in thread
From: tip-bot for Masami Hiramatsu @ 2017-12-28 15:32 UTC (permalink / raw)
To: linux-tip-commits
Cc: bhargavaramudu, linux-kernel, mingo, acme, pc, tglx, mhiramat,
ravi.bangoria, hpa, tmricht
Commit-ID: c588d158124d5b60184fc612e551a19720720d68
Gitweb: https://git.kernel.org/tip/c588d158124d5b60184fc612e551a19720720d68
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Wed, 13 Dec 2017 00:05:12 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 27 Dec 2017 12:15:55 -0300
perf probe: Support escaped character in parser
Support the special characters escaped by '\' in parser. This allows
user to specify versions directly like below.
=====
# ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5
Added new event:
probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
You can now use it in all perf tools, such as:
perf record -e probe_libc:malloc_get_state -aR sleep 1
=====
Or, you can use separators in source filename, e.g.
=====
# ./perf probe -x /opt/test/a.out foo+bar.c:3
Semantic error :There is non-digit character in offset.
Error: Command Parse Error.
=====
Usually "+" in source file cause parser error, but
=====
# ./perf probe -x /opt/test/a.out foo\\+bar.c:4
Added new event:
probe_a:main (on @foo+bar.c:4 in /opt/test/a.out)
You can now use it in all perf tools, such as:
perf record -e probe_a:main -aR sleep 1
=====
escaped "\+" allows you to specify that.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: bhargavb <bhargavaramudu@gmail.com>
Cc: linux-rt-users@vger.kernel.org
Link: http://lkml.kernel.org/r/151309111236.18107.5634753157435343410.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/Documentation/perf-probe.txt | 16 +++++++++
tools/perf/util/probe-event.c | 58 ++++++++++++++++++++-------------
2 files changed, 51 insertions(+), 23 deletions(-)
diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index f963826..b6866a0 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -182,6 +182,14 @@ Note that before using the SDT event, the target binary (on which SDT events are
For details of the SDT, see below.
https://sourceware.org/gdb/onlinedocs/gdb/Static-Probe-Points.html
+ESCAPED CHARACTER
+-----------------
+
+In the probe syntax, '=', '@', '+', ':' and ';' are treated as a special character. You can use a backslash ('\') to escape the special characters.
+This is useful if you need to probe on a specific versioned symbols, like @GLIBC_... suffixes, or also you need to specify a source file which includes the special characters.
+Note that usually single backslash is consumed by shell, so you might need to pass double backslash (\\) or wrapping with single quotes (\'AAA\@BBB').
+See EXAMPLES how it is used.
+
PROBE ARGUMENT
--------------
Each probe argument follows below syntax.
@@ -277,6 +285,14 @@ Add a USDT probe to a target process running in a different mount namespace
./perf probe --target-ns <target pid> -x /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-0.b13.el7_3.x86_64/jre/lib/amd64/server/libjvm.so %sdt_hotspot:thread__sleep__end
+Add a probe on specific versioned symbol by backslash escape
+
+ ./perf probe -x /lib64/libc-2.25.so 'malloc_get_state\@GLIBC_2.2.5'
+
+Add a probe in a source file using special characters by backslash escape
+
+ ./perf probe -x /opt/test/a.out 'foo\+bar.c:4'
+
SEE ALSO
--------
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0d6c66d..e1dbc98 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1325,27 +1325,30 @@ static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
{
char *ptr;
- ptr = strchr(*arg, ':');
+ ptr = strpbrk_esc(*arg, ":");
if (ptr) {
*ptr = '\0';
if (!pev->sdt && !is_c_func_name(*arg))
goto ng_name;
- pev->group = strdup(*arg);
+ pev->group = strdup_esc(*arg);
if (!pev->group)
return -ENOMEM;
*arg = ptr + 1;
} else
pev->group = NULL;
- if (!pev->sdt && !is_c_func_name(*arg)) {
+
+ pev->event = strdup_esc(*arg);
+ if (pev->event == NULL)
+ return -ENOMEM;
+
+ if (!pev->sdt && !is_c_func_name(pev->event)) {
+ zfree(&pev->event);
ng_name:
+ zfree(&pev->group);
semantic_error("%s is bad for event name -it must "
"follow C symbol-naming rule.\n", *arg);
return -EINVAL;
}
- pev->event = strdup(*arg);
- if (pev->event == NULL)
- return -ENOMEM;
-
return 0;
}
@@ -1373,7 +1376,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
arg++;
}
- ptr = strpbrk(arg, ";=@+%");
+ ptr = strpbrk_esc(arg, ";=@+%");
if (pev->sdt) {
if (ptr) {
if (*ptr != '@') {
@@ -1387,7 +1390,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
pev->target = build_id_cache__origname(tmp);
free(tmp);
} else
- pev->target = strdup(ptr + 1);
+ pev->target = strdup_esc(ptr + 1);
if (!pev->target)
return -ENOMEM;
*ptr = '\0';
@@ -1421,13 +1424,14 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
*
* Otherwise, we consider arg to be a function specification.
*/
- if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) {
+ if (!strpbrk_esc(arg, "+@%")) {
+ ptr = strpbrk_esc(arg, ";:");
/* This is a file spec if it includes a '.' before ; or : */
- if (memchr(arg, '.', ptr - arg))
+ if (ptr && memchr(arg, '.', ptr - arg))
file_spec = true;
}
- ptr = strpbrk(arg, ";:+@%");
+ ptr = strpbrk_esc(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
@@ -1436,7 +1440,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
if (arg[0] == '\0')
tmp = NULL;
else {
- tmp = strdup(arg);
+ tmp = strdup_esc(arg);
if (tmp == NULL)
return -ENOMEM;
}
@@ -1469,12 +1473,12 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
arg = ptr;
c = nc;
if (c == ';') { /* Lazy pattern must be the last part */
- pp->lazy_line = strdup(arg);
+ pp->lazy_line = strdup(arg); /* let leave escapes */
if (pp->lazy_line == NULL)
return -ENOMEM;
break;
}
- ptr = strpbrk(arg, ";:+@%");
+ ptr = strpbrk_esc(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
@@ -1501,7 +1505,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
semantic_error("SRC@SRC is not allowed.\n");
return -EINVAL;
}
- pp->file = strdup(arg);
+ pp->file = strdup_esc(arg);
if (pp->file == NULL)
return -ENOMEM;
break;
@@ -2803,23 +2807,31 @@ static int find_probe_functions(struct map *map, char *name,
struct rb_node *tmp;
const char *norm, *ver;
char *buf = NULL;
+ bool cut_version = true;
if (map__load(map) < 0)
return 0;
+ /* If user gives a version, don't cut off the version from symbols */
+ if (strchr(name, '@'))
+ cut_version = false;
+
map__for_each_symbol(map, sym, tmp) {
norm = arch__normalize_symbol_name(sym->name);
if (!norm)
continue;
- /* We don't care about default symbol or not */
- ver = strchr(norm, '@');
- if (ver) {
- buf = strndup(norm, ver - norm);
- if (!buf)
- return -ENOMEM;
- norm = buf;
+ if (cut_version) {
+ /* We don't care about default symbol or not */
+ ver = strchr(norm, '@');
+ if (ver) {
+ buf = strndup(norm, ver - norm);
+ if (!buf)
+ return -ENOMEM;
+ norm = buf;
+ }
}
+
if (strglobmatch(norm, name)) {
found++;
if (syms && found < probe_conf.max_probes)
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-12-28 15:35 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-12-12 15:05 [PATCH v4] perf-probe: Support escaped character in parser Masami Hiramatsu
2017-12-12 15:27 ` Arnaldo Carvalho de Melo
2017-12-13 13:40 ` Masami Hiramatsu
2017-12-13 15:42 ` Arnaldo Carvalho de Melo
2017-12-16 14:52 ` Masami Hiramatsu
2017-12-28 15:32 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
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