perf probe: Check symbols in symtab/kallsyms
Masami Hiramatsu [Tue, 15 Dec 2009 15:32:40 +0000 (10:32 -0500)]
Check symbols in symtab/kallsyms when no debuginfo
is available.

e.g.

 # perf probe test
  Fatal: Kernel symbol 'test' not found - probe not added.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091215153239.17436.55034.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-probe.c

index 0584b7a..6b0e4cf 100644 (file)
@@ -59,6 +59,7 @@ static struct {
        struct strlist *dellist;
        struct symbol_conf conf;
        struct perf_session *psession;
+       struct map *kmap;
 } session;
 
 
@@ -115,22 +116,26 @@ static int opt_del_probe_event(const struct option *opt __used,
        return 0;
 }
 
+/* Currently just checking function name from symbol map */
+static void evaluate_probe_point(struct probe_point *pp)
+{
+       struct symbol *sym;
+       sym = map__find_symbol_by_name(session.kmap, pp->function,
+                                      session.psession, NULL);
+       if (!sym)
+               die("Kernel symbol \'%s\' not found - probe not added.",
+                   pp->function);
+}
+
 #ifndef NO_LIBDWARF
 static int open_vmlinux(void)
 {
-       struct map *kmap;
-       kmap = map_groups__find_by_name(&session.psession->kmaps,
-                                       MAP__FUNCTION, "[kernel.kallsyms]");
-       if (!kmap) {
-               pr_debug("Could not find kernel map.\n");
-               return -ENOENT;
-       }
-       if (map__load(kmap, session.psession, NULL) < 0) {
+       if (map__load(session.kmap, session.psession, NULL) < 0) {
                pr_debug("Failed to load kernel map.\n");
                return -EINVAL;
        }
-       pr_debug("Try to open %s\n", kmap->dso->long_name);
-       return open(kmap->dso->long_name, O_RDONLY);
+       pr_debug("Try to open %s\n", session.kmap->dso->long_name);
+       return open(session.kmap->dso->long_name, O_RDONLY);
 }
 #endif
 
@@ -219,6 +224,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
        }
 
        /* Initialize symbol maps for vmlinux */
+       session.conf.sort_by_name = true;
        if (session.conf.vmlinux_name == NULL)
                session.conf.try_vmlinux_path = true;
        if (symbol__init(&session.conf) < 0)
@@ -227,6 +233,11 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
                                             &session.conf);
        if (session.psession == NULL)
                die("Failed to init perf_session.");
+       session.kmap = map_groups__find_by_name(&session.psession->kmaps,
+                                               MAP__FUNCTION,
+                                               "[kernel.kallsyms]");
+       if (!session.kmap)
+               die("Could not find kernel map.\n");
 
        if (session.need_dwarf)
 #ifdef NO_LIBDWARF
@@ -277,6 +288,7 @@ end_dwarf:
                if (pp->found)  /* This probe is already found. */
                        continue;
 
+               evaluate_probe_point(pp);
                ret = synthesize_trace_kprobe_event(pp);
                if (ret == -E2BIG)
                        die("probe point definition becomes too long.");