perf probe: Add lazy line matching support

Add lazy line matching support for specifying new probes.
This also changes the syntax of perf probe a bit. Now
perf probe accepts one of below probe event definitions.

1) Define event based on function name
 [EVENT=]FUNC[@SRC][:RLN|+OFF|%return|;PTN] [ARG ...]

2) Define event based on source file with line number
 [EVENT=]SRC:ALN [ARG ...]

3) Define event based on source file with lazy pattern
 [EVENT=]SRC;PTN [ARG ...]

- New lazy matching pattern(PTN) follows ';' (semicolon). And it
  must be put the end of the definition.
- So, @SRC is no longer the part which must be put at the end
  of the definition.

Note that ';' (semicolon) can be interpreted as the end of
a command by the shell. This means that you need to quote it.
(anyway you will need to quote the lazy pattern itself too,
because it may contains other sensitive characters, like
'[',']' etc.).

Lazy matching
-------------
The lazy line matching is similar to glob matching except
ignoring spaces in both of pattern and target.

e.g.
'a=*' can matches 'a=b', 'a = b', 'a == b' and so on.

This provides some sort of flexibility and robustness to
probe point definitions against minor code changes.
(for example, actual 10th line of schedule() can be changed
 easily by modifying schedule(), but the same line matching
 'rq=cpu_rq*' may still exist.)

Changes in v3:
 - Cast Dwarf_Addr to uintmax_t for printf-formats.

Changes in v2:
 - Cast Dwarf_Addr to unsigned long long for printf-formats.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133611.6725.45078.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 30 insertions, 18 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 91f55f24fa9d..fa156f008e0b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -119,14 +119,14 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
         char c, nc = 0;
         /*
          * <Syntax>
-         * perf probe [EVENT=]SRC:LN
-         * perf probe [EVENT=]FUNC[+OFFS|%return][@SRC]
+         * perf probe [EVENT=]SRC[:LN|;PTN]
+         * perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
          *
          * TODO:Group name support
          */
 
-        ptr = strchr(arg, '=');
-        if (ptr) {      /* Event name */
+        ptr = strpbrk(arg, ";=@+%");
+        if (ptr && *ptr == '=') {       /* Event name */
                 *ptr = '\0';
                 tmp = ptr + 1;
                 ptr = strchr(arg, ':');
@@ -139,7 +139,7 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
                 arg = tmp;
         }
 
-        ptr = strpbrk(arg, ":+@%");
+        ptr = strpbrk(arg, ";:+@%");
         if (ptr) {
                 nc = *ptr;
                 *ptr++ = '\0';
@@ -156,7 +156,11 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
         while (ptr) {
                 arg = ptr;
                 c = nc;
-                ptr = strpbrk(arg, ":+@%");
+                if (c == ';') { /* Lazy pattern must be the last part */
+                        pp->lazy_line = strdup(arg);
+                        break;
+                }
+                ptr = strpbrk(arg, ";:+@%");
                 if (ptr) {
                         nc = *ptr;
                         *ptr++ = '\0';
@@ -165,13 +169,13 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
                 case ':':       /* Line number */
                         pp->line = strtoul(arg, &tmp, 0);
                         if (*tmp != '\0')
-                                semantic_error("There is non-digit charactor"
-                                                " in line number.");
+                                semantic_error("There is non-digit char"
+                                               " in line number.");
                         break;
                 case '+':       /* Byte offset from a symbol */
                         pp->offset = strtoul(arg, &tmp, 0);
                         if (*tmp != '\0')
-                                semantic_error("There is non-digit charactor"
+                                semantic_error("There is non-digit character"
                                                 " in offset.");
                         break;
                 case '@':       /* File name */
@@ -179,9 +183,6 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
                                 semantic_error("SRC@SRC is not allowed.");
                         pp->file = strdup(arg);
                         DIE_IF(pp->file == NULL);
-                        if (ptr)
-                                semantic_error("@SRC must be the last "
-                                               "option.");
                         break;
                 case '%':       /* Probe places */
                         if (strcmp(arg, "return") == 0) {
@@ -196,11 +197,18 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
         }
 
         /* Exclusion check */
+        if (pp->lazy_line && pp->line)
+                semantic_error("Lazy pattern can't be used with line number.");
+
+        if (pp->lazy_line && pp->offset)
+                semantic_error("Lazy pattern can't be used with offset.");
+
         if (pp->line && pp->offset)
                 semantic_error("Offset can't be used with line number.");
 
-        if (!pp->line && pp->file && !pp->function)
-                semantic_error("File always requires line number.");
+        if (!pp->line && !pp->lazy_line && pp->file && !pp->function)
+                semantic_error("File always requires line number or "
+                               "lazy pattern.");
 
         if (pp->offset && !pp->function)
                 semantic_error("Offset requires an entry function.");
@@ -208,11 +216,13 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
         if (pp->retprobe && !pp->function)
                 semantic_error("Return probe requires an entry function.");
 
-        if ((pp->offset || pp->line) && pp->retprobe)
-                semantic_error("Offset/Line can't be used with return probe.");
+        if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe)
+                semantic_error("Offset/Line/Lazy pattern can't be used with "
+                               "return probe.");
 
-        pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
-                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
+        pr_debug("symbol:%s file:%s line:%d offset:%d return:%d lazy:%s\n",
+                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
+                 pp->lazy_line);
 }
 
 /* Parse perf-probe event definition */
@@ -456,6 +466,8 @@ static void clear_probe_point(struct probe_point *pp)
                 free(pp->function);
         if (pp->file)
                 free(pp->file);
+        if (pp->lazy_line)
+                free(pp->lazy_line);
         for (i = 0; i < pp->nr_args; i++)
                 free(pp->args[i]);
         if (pp->args)