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-rw-r--r--kernel/bpf/helpers.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a74972b07e74..a411fc17d265 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -221,6 +221,102 @@ const struct bpf_func_proto bpf_get_current_comm_proto = {
.arg2_type = ARG_CONST_SIZE,
};
+#if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
+
+static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
+{
+ arch_spinlock_t *l = (void *)lock;
+ union {
+ __u32 val;
+ arch_spinlock_t lock;
+ } u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
+
+ compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
+ BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
+ BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
+ arch_spin_lock(l);
+}
+
+static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
+{
+ arch_spinlock_t *l = (void *)lock;
+
+ arch_spin_unlock(l);
+}
+
+#else
+
+static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
+{
+ atomic_t *l = (void *)lock;
+
+ BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
+ do {
+ atomic_cond_read_relaxed(l, !VAL);
+ } while (atomic_xchg(l, 1));
+}
+
+static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
+{
+ atomic_t *l = (void *)lock;
+
+ atomic_set_release(l, 0);
+}
+
+#endif
+
+static DEFINE_PER_CPU(unsigned long, irqsave_flags);
+
+notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __bpf_spin_lock(lock);
+ __this_cpu_write(irqsave_flags, flags);
+ return 0;
+}
+
+const struct bpf_func_proto bpf_spin_lock_proto = {
+ .func = bpf_spin_lock,
+ .gpl_only = false,
+ .ret_type = RET_VOID,
+ .arg1_type = ARG_PTR_TO_SPIN_LOCK,
+};
+
+notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+ unsigned long flags;
+
+ flags = __this_cpu_read(irqsave_flags);
+ __bpf_spin_unlock(lock);
+ local_irq_restore(flags);
+ return 0;
+}
+
+const struct bpf_func_proto bpf_spin_unlock_proto = {
+ .func = bpf_spin_unlock,
+ .gpl_only = false,
+ .ret_type = RET_VOID,
+ .arg1_type = ARG_PTR_TO_SPIN_LOCK,
+};
+
+void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
+ bool lock_src)
+{
+ struct bpf_spin_lock *lock;
+
+ if (lock_src)
+ lock = src + map->spin_lock_off;
+ else
+ lock = dst + map->spin_lock_off;
+ preempt_disable();
+ ____bpf_spin_lock(lock);
+ copy_map_value(map, dst, src);
+ ____bpf_spin_unlock(lock);
+ preempt_enable();
+}
+
#ifdef CONFIG_CGROUPS
BPF_CALL_0(bpf_get_current_cgroup_id)
{