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Commit b64b0077 authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

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: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
parent 7e4e28c5

kernel/trace/trace_probe.h

+0 −1
Original line number Original line Diff line number Diff line
@@ -66,7 +66,6 @@ 
#define TP_FLAG_TRACE		1

#define TP_FLAG_TRACE		1

#define TP_FLAG_PROFILE		2

#define TP_FLAG_PROFILE		2

#define TP_FLAG_REGISTERED	4

#define TP_FLAG_REGISTERED	4

#define TP_FLAG_UPROBE		8









/* data_rloc: data relative location, compatible with u32 */

/* data_rloc: data relative location, compatible with u32 */

kernel/trace/trace_uprobe.c

+7 −2
Original line number Original line Diff line number Diff line
@@ -539,12 +539,17 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e 
	return TRACE_TYPE_PARTIAL_LINE;

	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)

static int probe_event_enable(struct trace_uprobe *tu, int flag)

{

{

	struct uprobe_trace_consumer *utc;

	struct uprobe_trace_consumer *utc;

	int ret = 0;

	int ret = 0;





	if (tu->consumer)

	if (is_trace_uprobe_enabled(tu))

		return -EINTR;

		return -EINTR;





	utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);

	utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
@@ -568,7 +573,7 @@ static int probe_event_enable(struct trace_uprobe *tu, int flag) 




static void probe_event_disable(struct trace_uprobe *tu, int flag)

static void probe_event_disable(struct trace_uprobe *tu, int flag)

{

{

	if (!tu->consumer)

	if (!is_trace_uprobe_enabled(tu))

		return;

		return;





	uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);

	uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);