Pull locking fixes from Thomas Gleixner: "Two fixes for locking and jump labels: - Ensure that the atomic_cmpxchg() conditions are correct and evaluating to true on any non-zero value except 1. The missing check of the return value leads to inconsisted state of the jump label counter. - Add a missing type conversion in the paravirt spinlock code which makes loongson build again" * tag 'locking-urgent-2024-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: jump_label: Fix the fix, brown paper bags galore locking/pvqspinlock: Correct the type of "old" variable in pv_kick_node()
Unified · Split
| @@ -236,7 +236,7 @@ void static_key_disable_cpuslocked(struct static_key *key) · 235 unmodified lines | |||
| 236 | } | 236 | } |
| 237 | 237 | ||
| 238 | jump_label_lock(); | 238 | jump_label_lock(); |
| 239 | if (atomic_cmpxchg(&key->enabled, 1, 0)) | 239 | if (atomic_cmpxchg(&key->enabled, 1, 0) == 1) |
| 240 | jump_label_update(key); | 240 | jump_label_update(key); |
| 241 | jump_label_unlock(); | 241 | jump_label_unlock(); |
| 242 | } | 242 | } |
| @@ -289,7 +289,7 @@ static void __static_key_slow_dec_cpuslocked(struct static_key *key) · 46 unmodified lines | |||
| 289 | return; | 289 | return; |
| 290 | 290 | ||
| 291 | guard(mutex)(&jump_label_mutex); | 291 | guard(mutex)(&jump_label_mutex); |
| 292 | if (atomic_cmpxchg(&key->enabled, 1, 0)) | 292 | if (atomic_cmpxchg(&key->enabled, 1, 0) == 1) |
| 293 | jump_label_update(key); | 293 | jump_label_update(key); |
| 294 | else | 294 | else |
| 295 | WARN_ON_ONCE(!static_key_slow_try_dec(key)); | 295 | WARN_ON_ONCE(!static_key_slow_try_dec(key)); |
| @@ -357,7 +357,7 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev) · 356 unmodified lines | |||
| 357 | static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node) | 357 | static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node) |
| 358 | { | 358 | { |
| 359 | struct pv_node *pn = (struct pv_node *)node; | 359 | struct pv_node *pn = (struct pv_node *)node; |
| 360 | enum vcpu_state old = vcpu_halted; | 360 | u8 old = vcpu_halted; |
| 361 | /* | 361 | /* |
| 362 | * If the vCPU is indeed halted, advance its state to match that of | 362 | * If the vCPU is indeed halted, advance its state to match that of |
| 363 | * pv_wait_node(). If OTOH this fails, the vCPU was running and will | 363 | * pv_wait_node(). If OTOH this fails, the vCPU was running and will |