smp/hotplug: Undo tglxs brainfart
The attempt to prevent overwriting an active state resulted in a
disaster which effectively disables all dynamically allocated hotplug
states.
Cleanup the mess.
Fixes: dc280d936239 ("cpu/hotplug: Prevent overwriting of callbacks")
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 042fd7e..f75c4d0 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1471,6 +1471,7 @@ int __cpuhp_setup_state(enum cpuhp_state state,
bool multi_instance)
{
int cpu, ret = 0;
+ bool dynstate;
if (cpuhp_cb_check(state) || !name)
return -EINVAL;
@@ -1480,6 +1481,12 @@ int __cpuhp_setup_state(enum cpuhp_state state,
ret = cpuhp_store_callbacks(state, name, startup, teardown,
multi_instance);
+ dynstate = state == CPUHP_AP_ONLINE_DYN;
+ if (ret > 0 && dynstate) {
+ state = ret;
+ ret = 0;
+ }
+
if (ret || !invoke || !startup)
goto out;
@@ -1508,7 +1515,7 @@ int __cpuhp_setup_state(enum cpuhp_state state,
* If the requested state is CPUHP_AP_ONLINE_DYN, return the
* dynamically allocated state in case of success.
*/
- if (!ret && state == CPUHP_AP_ONLINE_DYN)
+ if (!ret && dynstate)
return state;
return ret;
}
