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Commit 292f60c0 authored by Julia Lawall's avatar Julia Lawall Committed by Steven Rostedt
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ring-buffer: Add missing unlock 

In some error handling cases the lock is not unlocked.  The return is
converted to a goto, to share the unlock at the end of the function.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irq (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>

Signed-off-by: default avatarJulia Lawall <julia@diku.dk>
LKML-Reference: <Pine.LNX.4.64.1003291736440.21896@ask.diku.dk>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent e36673ec

kernel/trace/ring_buffer.c

+5 −3
Original line number Diff line number Diff line
@@ -1209,18 +1209,19 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) 


	for (i = 0; i < nr_pages; i++) {

		if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))

			return;

			goto out;

		p = cpu_buffer->pages->next;

		bpage = list_entry(p, struct buffer_page, list);

		list_del_init(&bpage->list);

		free_buffer_page(bpage);

	}

	if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))

		return;

		goto out;



	rb_reset_cpu(cpu_buffer);

	rb_check_pages(cpu_buffer);



out:

	spin_unlock_irq(&cpu_buffer->reader_lock);

}
@@ -1237,7 +1238,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, 


	for (i = 0; i < nr_pages; i++) {

		if (RB_WARN_ON(cpu_buffer, list_empty(pages)))

			return;

			goto out;

		p = pages->next;

		bpage = list_entry(p, struct buffer_page, list);

		list_del_init(&bpage->list);
@@ -1246,6 +1247,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, 
	rb_reset_cpu(cpu_buffer);

	rb_check_pages(cpu_buffer);



out:

	spin_unlock_irq(&cpu_buffer->reader_lock);

}