Precede a 'sev' with a 'dsb' in bakery lock code
This patch fixes a bug in the bakery lock implementation where a data
synchronisation barrier instruction is not issued before sending an event as
mandated by the ARMv8 ARM. This can cause a event to be signalled before the
related memory accesses have completed resulting in erroneous execution.
Fixes ARM-software/tf-issues#272
Change-Id: I5ce02bf70afb001d967b9fa4c3f77442931d5349
diff --git a/lib/locks/bakery/bakery_lock.c b/lib/locks/bakery/bakery_lock.c
index 877f526..7e71dec 100644
--- a/lib/locks/bakery/bakery_lock.c
+++ b/lib/locks/bakery/bakery_lock.c
@@ -107,6 +107,7 @@
++my_ticket;
bakery->number[me] = my_ticket;
bakery->entering[me] = 0;
+ dsb();
sev();
return my_ticket;
@@ -189,5 +190,6 @@
*/
bakery->owner = NO_OWNER;
bakery->number[me] = 0;
+ dsb();
sev();
}