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

Masami Hiramatsu
2019-06-19T15:08:24Z

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@kernel.org>
---
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 *