uprobes/tracing: Introduce is_trace_uprobe_enabled()
probe_event_enable/disable() check tu->consumer != NULL to avoid the
wrong uprobe_register/unregister().
We are going to kill this pointer and "struct uprobe_trace_consumer",
so we add the new helper, is_trace_uprobe_enabled(), which can rely
on TP_FLAG_TRACE/TP_FLAG_PROFILE instead.
Note: the current logic doesn't look optimal, it is not clear why
TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably
change this later.
Also kill the unused TP_FLAG_UPROBE.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f7838cf..d6c6e2a 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -539,12 +539,17 @@
return TRACE_TYPE_PARTIAL_LINE;
}
+static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu)
+{
+ return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE);
+}
+
static int probe_event_enable(struct trace_uprobe *tu, int flag)
{
struct uprobe_trace_consumer *utc;
int ret = 0;
- if (tu->consumer)
+ if (is_trace_uprobe_enabled(tu))
return -EINTR;
utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
@@ -568,7 +573,7 @@
static void probe_event_disable(struct trace_uprobe *tu, int flag)
{
- if (!tu->consumer)
+ if (!is_trace_uprobe_enabled(tu))
return;
uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);