perf probe: List probes with line number and file name

Improve --list to show current exist probes with line number and
file name. This enables user easily to check which line is
already probed.

for example:

 ./perf probe --list
 probe:vfs_read       (on vfs_read:8@linux-2.6-tip/fs/read_write.c)

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: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100316220619.32050.48702.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index b44ddfb..4e3c1ae 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -70,7 +70,6 @@ static int e_snprintf(char *str, size_t size, const char *format, ...)
        return ret;
 }
 
-
 static struct map_groups kmap_groups;
 static struct map *kmaps[MAP__NR_TYPES];
 
@@ -357,27 +356,39 @@ void parse_kprobe_trace_command(const char *cmd, struct kprobe_trace_event *tev)
 /* Compose only probe point (not argument) */
 static char *synthesize_perf_probe_point(struct perf_probe_point *pp)
 {
-       char *buf;
-       char offs[64] = "", line[64] = "";
-       int ret;
+       char *buf, *tmp;
+       char offs[32] = "", line[32] = "", file[32] = "";
+       int ret, len;
 
        buf = xzalloc(MAX_CMDLEN);
        if (pp->offset) {
-               ret = e_snprintf(offs, 64, "+%lu", pp->offset);
+               ret = e_snprintf(offs, 32, "+%lu", pp->offset);
                if (ret <= 0)
                        goto error;
        }
        if (pp->line) {
-               ret = e_snprintf(line, 64, ":%d", pp->line);
+               ret = e_snprintf(line, 32, ":%d", pp->line);
+               if (ret <= 0)
+                       goto error;
+       }
+       if (pp->file) {
+               len = strlen(pp->file) - 32;
+               if (len < 0)
+                       len = 0;
+               tmp = strchr(pp->file + len, '/');
+               if (!tmp)
+                       tmp = pp->file + len - 1;
+               ret = e_snprintf(file, 32, "@%s", tmp + 1);
                if (ret <= 0)
                        goto error;
        }
 
        if (pp->function)
-               ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->function,
-                                offs, pp->retprobe ? "%return" : "", line);
+               ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s%s", pp->function,
+                                offs, pp->retprobe ? "%return" : "", line,
+                                file);
        else
-               ret = e_snprintf(buf, MAX_CMDLEN, "%s%s", pp->file, line);
+               ret = e_snprintf(buf, MAX_CMDLEN, "%s%s", file, line);
        if (ret <= 0)
                goto error;
 
@@ -511,15 +522,32 @@ void convert_to_perf_probe_event(struct kprobe_trace_event *tev,
 {
        char buf[64];
        int i;
+#ifndef NO_DWARF_SUPPORT
+       struct symbol *sym;
+       int fd, ret = 0;
 
-       pev->event = xstrdup(tev->event);
-       pev->group = xstrdup(tev->group);
-
+       sym = map__find_symbol_by_name(kmaps[MAP__FUNCTION],
+                                      tev->point.symbol, NULL);
+       if (sym) {
+               fd = open_vmlinux();
+               ret = find_perf_probe_point(fd, sym->start + tev->point.offset,
+                                           &pev->point);
+               close(fd);
+       }
+       if (ret <= 0) {
+               pev->point.function = xstrdup(tev->point.symbol);
+               pev->point.offset = tev->point.offset;
+       }
+#else
        /* Convert trace_point to probe_point */
        pev->point.function = xstrdup(tev->point.symbol);
        pev->point.offset = tev->point.offset;
+#endif
        pev->point.retprobe = tev->point.retprobe;
 
+       pev->event = xstrdup(tev->event);
+       pev->group = xstrdup(tev->group);
+
        /* Convert trace_arg to probe_arg */
        pev->nargs = tev->nargs;
        pev->args = xzalloc(sizeof(struct perf_probe_arg) * pev->nargs);
@@ -650,7 +678,7 @@ static void show_perf_probe_event(struct perf_probe_event *pev)
        ret = e_snprintf(buf, 128, "%s:%s", pev->group, pev->event);
        if (ret < 0)
                die("Failed to copy event: %s", strerror(-ret));
-       printf("  %-40s (on %s", buf, place);
+       printf("  %-20s (on %s", buf, place);
 
        if (pev->nargs > 0) {
                printf(" with");
@@ -671,6 +699,7 @@ void show_perf_probe_events(void)
        struct str_node *ent;
 
        setup_pager();
+       init_vmlinux();
 
        memset(&tev, 0, sizeof(tev));
        memset(&pev, 0, sizeof(pev));

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 251b4c4..e02b607 100644 (file)
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -693,6 +693,76 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
        return pf.ntevs;
 }
 
+/* Reverse search */
+int find_perf_probe_point(int fd, unsigned long addr,
+                         struct perf_probe_point *ppt)
+{
+       Dwarf_Die cudie, spdie, indie;
+       Dwarf *dbg;
+       Dwarf_Line *line;
+       Dwarf_Addr laddr, eaddr;
+       const char *tmp;
+       int lineno, ret = 0;
+
+       dbg = dwarf_begin(fd, DWARF_C_READ);
+       if (!dbg)
+               return -ENOENT;
+
+       /* Find cu die */
+       if (!dwarf_addrdie(dbg, (Dwarf_Addr)addr, &cudie))
+               return -EINVAL;
+
+       /* Find a corresponding line */
+       line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr);
+       if (line) {
+               dwarf_lineaddr(line, &laddr);
+               if ((Dwarf_Addr)addr == laddr) {
+                       dwarf_lineno(line, &lineno);
+                       ppt->line = lineno;
+
+                       tmp = dwarf_linesrc(line, NULL, NULL);
+                       DIE_IF(!tmp);
+                       ppt->file = xstrdup(tmp);
+                       ret = 1;
+               }
+       }
+
+       /* Find a corresponding function */
+       if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) {
+               tmp = dwarf_diename(&spdie);
+               if (!tmp)
+                       goto end;
+
+               dwarf_entrypc(&spdie, &eaddr);
+               if (!lineno) {
+                       /* We don't have a line number, let's use offset */
+                       ppt->function = xstrdup(tmp);
+                       ppt->offset = addr - (unsigned long)eaddr;
+                       ret = 1;
+                       goto end;
+               }
+               if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, &indie)) {
+                       /* addr in an inline function */
+                       tmp = dwarf_diename(&indie);
+                       if (!tmp)
+                               goto end;
+                       dwarf_decl_line(&indie, &lineno);
+               } else {
+                       if (eaddr == addr)      /* No offset: function entry */
+                               lineno = ppt->line;
+                       else
+                               dwarf_decl_line(&spdie, &lineno);
+               }
+               ppt->function = xstrdup(tmp);
+               ppt->line -= lineno;    /* Make a relative line number */
+       }
+
+end:
+       dwarf_end(dbg);
+       return ret;
+}
+
+
 /* Find line range from its line number */
 static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
 {

diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 4949526..2f2307d 100644 (file)
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -20,6 +20,10 @@ static inline int is_c_varname(const char *name)
 extern int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
                                    struct kprobe_trace_event **tevs);
 
+/* Find a perf_probe_point from debuginfo */
+extern int find_perf_probe_point(int fd, unsigned long addr,
+                                struct perf_probe_point *ppt);
+
 extern int find_line_range(int fd, struct line_range *lr);
 
 #include <dwarf.h>