[PATCH v2 07/12] tracing/uprobe: Add per-probe delete from event

[Masami Hiramatsu]

Add per-probe delete method from one event passing the head of
definition. In other words, the events which match the head
N parameters are deleted.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
 Changes in v2:
  - Swap the checking order of filename for avoiding unexpected memory
    access.
---
 kernel/trace/trace_uprobe.c |   31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c568f7b16f5c..878219552177 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -284,13 +284,42 @@ static bool trace_uprobe_is_busy(struct dyn_event *ev)
 	return trace_probe_is_enabled(&tu->tp);
 }
 
+static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
+					    int argc, const char **argv)
+{
+	char buf[MAX_ARGSTR_LEN + 1];
+	int len;
+
+	if (!argc)
+		return true;
+
+	len = strlen(tu->filename);
+	if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
+		return false;
+
+	if (tu->ref_ctr_offset == 0)
+		snprintf(buf, sizeof(buf), "0x%0*lx",
+				(int)(sizeof(void *) * 2), tu->offset);
+	else
+		snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
+				(int)(sizeof(void *) * 2), tu->offset,
+				tu->ref_ctr_offset);
+	if (strcmp(buf, &argv[0][len + 1]))
+		return false;
+
+	argc--; argv++;
+
+	return trace_probe_match_command_args(&tu->tp, argc, argv);
+}
+
 static bool trace_uprobe_match(const char *system, const char *event,
 			int argc, const char **argv, struct dyn_event *ev)
 {
 	struct trace_uprobe *tu = to_trace_uprobe(ev);
 
 	return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
-	    (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0);
+	   (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
+	   trace_uprobe_match_command_head(tu, argc, argv);
 }
 
 static nokprobe_inline struct trace_uprobe *