tracing: Integrate similar probe argument parsers

Integrate similar argument parsers for kprobes and uprobes events
into traceprobe_parse_probe_arg().

Link: http://lkml.kernel.org/r/154140850016.17322.9836787731210512176.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 44 insertions, 3 deletions

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index bd30e9398d2a..449150c6a87f 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -348,7 +348,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
 }
 
 /* String length checking wrapper */
-int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
+static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
 		struct probe_arg *parg, unsigned int flags)
 {
 	struct fetch_insn *code, *scode, *tmp = NULL;
@@ -491,8 +491,8 @@ fail:
 }
 
 /* Return 1 if name is reserved or already used by another argument */
-int traceprobe_conflict_field_name(const char *name,
-			       struct probe_arg *args, int narg)
+static int traceprobe_conflict_field_name(const char *name,
+					  struct probe_arg *args, int narg)
 {
 	int i;
 
@@ -507,6 +507,47 @@ int traceprobe_conflict_field_name(const char *name,
 	return 0;
 }
 
+int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
+				unsigned int flags)
+{
+	struct probe_arg *parg = &tp->args[i];
+	char *body;
+	int ret;
+
+	/* Increment count for freeing args in error case */
+	tp->nr_args++;
+
+	body = strchr(arg, '=');
+	if (body) {
+		parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
+		body++;
+	} else {
+		/* If argument name is omitted, set "argN" */
+		parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
+		body = arg;
+	}
+	if (!parg->name)
+		return -ENOMEM;
+
+	if (!is_good_name(parg->name)) {
+		pr_info("Invalid argument[%d] name: %s\n",
+			i, parg->name);
+		return -EINVAL;
+	}
+
+	if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
+		pr_info("Argument[%d]: '%s' conflicts with another field.\n",
+			i, parg->name);
+		return -EINVAL;
+	}
+
+	/* Parse fetch argument */
+	ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags);
+	if (ret)
+		pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
+	return ret;
+}
+
 void traceprobe_free_probe_arg(struct probe_arg *arg)
 {
 	struct fetch_insn *code = arg->code;