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authorMasami Hiramatsu <mhiramat@kernel.org>2019-09-18 11:55:46 +0300
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-09-19 18:09:16 +0300
commitfe60b0ce8e7335269722ec080173a9411a9d58a5 (patch)
treeeb5e1017f436280c01a4d0ef65710437bfaa6d88 /kernel/trace/trace_uprobe.c
parent44d00dc7ceab1732ebd5f5aae601b24dacdf10c5 (diff)
downloadlinux-fe60b0ce8e7335269722ec080173a9411a9d58a5.tar.xz
tracing/probe: Reject exactly same probe event
Reject exactly same probe events as existing probes. Multiprobe allows user to define multiple probes on same event. If user appends a probe which exactly same definition (same probe address and same arguments) on existing event, the event will record same probe information twice. That can be confusing users, so reject it. Link: http://lkml.kernel.org/r/156879694602.31056.5533024778165036763.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_uprobe.c')
-rw-r--r--kernel/trace/trace_uprobe.c52
1 files changed, 44 insertions, 8 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index cbf4da4bf367..34dd6d0016a3 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -410,10 +410,53 @@ unreg:
return 0;
}
+static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
+ struct trace_uprobe *comp)
+{
+ struct trace_probe_event *tpe = orig->tp.event;
+ struct trace_probe *pos;
+ struct inode *comp_inode = d_real_inode(comp->path.dentry);
+ int i;
+
+ list_for_each_entry(pos, &tpe->probes, list) {
+ orig = container_of(pos, struct trace_uprobe, tp);
+ if (comp_inode != d_real_inode(orig->path.dentry) ||
+ comp->offset != orig->offset)
+ continue;
+
+ /*
+ * trace_probe_compare_arg_type() ensured that nr_args and
+ * each argument name and type are same. Let's compare comm.
+ */
+ for (i = 0; i < orig->tp.nr_args; i++) {
+ if (strcmp(orig->tp.args[i].comm,
+ comp->tp.args[i].comm))
+ continue;
+ }
+
+ return true;
+ }
+
+ return false;
+}
+
static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
{
int ret;
+ ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
+ if (ret) {
+ /* Note that argument starts index = 2 */
+ trace_probe_log_set_index(ret + 1);
+ trace_probe_log_err(0, DIFF_ARG_TYPE);
+ return -EEXIST;
+ }
+ if (trace_uprobe_has_same_uprobe(to, tu)) {
+ trace_probe_log_set_index(0);
+ trace_probe_log_err(0, SAME_PROBE);
+ return -EEXIST;
+ }
+
/* Append to existing event */
ret = trace_probe_append(&tu->tp, &to->tp);
if (!ret)
@@ -469,14 +512,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
trace_probe_log_err(0, DIFF_PROBE_TYPE);
ret = -EEXIST;
} else {
- ret = trace_probe_compare_arg_type(&tu->tp, &old_tu->tp);
- if (ret) {
- /* Note that argument starts index = 2 */
- trace_probe_log_set_index(ret + 1);
- trace_probe_log_err(0, DIFF_ARG_TYPE);
- ret = -EEXIST;
- } else
- ret = append_trace_uprobe(tu, old_tu);
+ ret = append_trace_uprobe(tu, old_tu);
}
goto end;
}