Fix CPU hotplug callbacks to disable interrupts on UP kernels.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmk74mgRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1jS2g/+NPDw1R7yAPHlTaZO6CduYSENXzTOjmG3
 BxdWERuta3Z78CNJZ5mtbrL1mBccG29oN+EZFGrKbDuxrR6SoglWUr1x1pYJRDyp
 h0DvBfzewXcVwOCiBQpqVzuQIzPqsF1IfdDP6eIGnkhnSAEi6ObIZeAbzBzZRovD
 dccU5e0LAIffTmAyKFYIqD4Fu90bzwJ3dAE1b0tP4mnm+jFGitdd8vb8mowiftOk
 Lij8hsy8bg2A5VThIlKow0ya4uc6Bb3ZGj6aiMHoGMPbB2pu3o8bNH/K9d1MsKIe
 AdZ6Y8mFriYYk3GEI3aWaoRkEXCZFX2IcOUS++yqvrOb88iJpW7jujgRIRvX0Px4
 5xgHomQwW9XQKJgNYU/xLgpQSvBH4IzGDX5Uf8oU+hqcjYJBJjy21Dk9JGJymjv/
 /jTq11Bd9xqzyv9W2Ysg2CfOA29+jGe8XlZU9ucOKE1bz09D+8R+H8X/LZtldjMa
 Xbr+7HG9AD13gLJW+PfRQbJR5CwoCvh9dPMzWtFLykxBYT/mQK5gs4OQDaG+JFsz
 8ov+F28O1KBCtcK+v2M/2mQlo51y6RI/t5cw1sVSosgORjHPIVpPjbbTGi0r4MKw
 PHBGdw0mb1dgsXMRNnCNwvfxZP/S1TnmbIkaT4THC0PqJHOloyrsVbXGD1u6F9In
 Gaodcvn7MbA=
 =jbkd
 -----END PGP SIGNATURE-----

Merge tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug fix from Ingo Molnar:

 - Fix CPU hotplug callbacks to disable interrupts on UP kernels

* tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu: Make atomic hotplug callbacks run with interrupts disabled on UP
master
Linus Torvalds 2025-12-14 06:12:46 +12:00
commit 4a298a43f5
1 changed files with 16 additions and 9 deletions

View File

@ -249,6 +249,14 @@ err:
return ret;
}
/*
* The former STARTING/DYING states, ran with IRQs disabled and must not fail.
*/
static bool cpuhp_is_atomic_state(enum cpuhp_state state)
{
return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE;
}
#ifdef CONFIG_SMP
static bool cpuhp_is_ap_state(enum cpuhp_state state)
{
@ -271,14 +279,6 @@ static inline void complete_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
complete(done);
}
/*
* The former STARTING/DYING states, ran with IRQs disabled and must not fail.
*/
static bool cpuhp_is_atomic_state(enum cpuhp_state state)
{
return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE;
}
/* Synchronization state management */
enum cpuhp_sync_state {
SYNC_STATE_DEAD,
@ -2364,7 +2364,14 @@ static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
else
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
#else
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
if (cpuhp_is_atomic_state(state)) {
guard(irqsave)();
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
/* STARTING/DYING must not fail! */
WARN_ON_ONCE(ret);
} else {
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
}
#endif
BUG_ON(ret && !bringup);
return ret;