static bool stf_exit_reentrant = false;
static bool rfi_exit_reentrant = false;
+static DEFINE_MUTEX(exit_flush_lock);
static int __do_stf_barrier_fixups(void *data)
{
* low level interrupt exit code before patching. After the patching,
* if allowed, then flip the branch to allow fast exits.
*/
+
+ // Prevent static key update races with do_rfi_flush_fixups()
+ mutex_lock(&exit_flush_lock);
static_branch_enable(&interrupt_exit_not_reentrant);
stop_machine(__do_stf_barrier_fixups, &types, NULL);
if (stf_exit_reentrant && rfi_exit_reentrant)
static_branch_disable(&interrupt_exit_not_reentrant);
+
+ mutex_unlock(&exit_flush_lock);
}
void do_uaccess_flush_fixups(enum l1d_flush_type types)
* without stop_machine, so this could be achieved with a broadcast
* IPI instead, but this matches the stf sequence.
*/
+
+ // Prevent static key update races with do_stf_barrier_fixups()
+ mutex_lock(&exit_flush_lock);
static_branch_enable(&interrupt_exit_not_reentrant);
stop_machine(__do_rfi_flush_fixups, &types, NULL);
if (stf_exit_reentrant && rfi_exit_reentrant)
static_branch_disable(&interrupt_exit_not_reentrant);
+
+ mutex_unlock(&exit_flush_lock);
}
void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)