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tracing/kprobes: Fix handling of argument names

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Set "argN" name for each argument automatically if it has no specified name.
Since dynamic trace event(kprobe_events) accepts special characters for its
argument, its format can show those special characters (e.g. '$', '%', '+').
However, perf can't parse those format because of the character (especially
'%') mess up the format.  This sets "argX" name for those arguments if user
omitted the argument names.

E.g.
 # echo 'p do_fork %ax IP=%ip $stack' > tracing/kprobe_events
 # cat tracing/kprobe_events
 p:kprobes/p_do_fork_0 do_fork arg1=%ax IP=%ip arg3=$stack

Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20100827113906.22882.59312.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2010-08-27 20:39:06 +09:00 committed by Arnaldo Carvalho de Melo
parent 367e94c100
commit aba91595cf
1 changed files with 10 additions and 7 deletions
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17
kernel/trace/trace_kprobe.c
View file

@ -997,15 +997,18 @@ static int create_trace_probe(int argc, char **argv)
/* Parse argument name */
arg = strchr(argv[i], '=');
if (arg)
if (arg) {
*arg++ = '\0';
else
tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
} else {
arg = argv[i];
/* If argument name is omitted, set "argN" */
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
tp->args[i].name = kstrdup(buf, GFP_KERNEL);
}
tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
if (!tp->args[i].name) {
pr_info("Failed to allocate argument%d name '%s'.\n",
i, argv[i]);
pr_info("Failed to allocate argument[%d] name.\n", i);
ret = -ENOMEM;
goto error;
}
@ -1014,7 +1017,7 @@ static int create_trace_probe(int argc, char **argv)
*tmp = '_'; /* convert : to _ */
if (conflict_field_name(tp->args[i].name, tp->args, i)) {
pr_info("Argument%d name '%s' conflicts with "
pr_info("Argument[%d] name '%s' conflicts with "
"another field.\n", i, argv[i]);
ret = -EINVAL;
goto error;
@ -1023,7 +1026,7 @@ static int create_trace_probe(int argc, char **argv)
/* Parse fetch argument */
ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
if (ret) {
pr_info("Parse error at argument%d. (%d)\n", i, ret);
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
}
}