3 files changed, 82 insertions, 0 deletions

diff --git a/include/asm-generic/rqspinlock.h b/include/asm-generic/rqspinlock.h
index 23abd0b8d0f9..6d4244d643df 100644
--- a/include/asm-generic/rqspinlock.h
+++ b/include/asm-generic/rqspinlock.h
@@ -23,6 +23,13 @@ struct rqspinlock {
 	};
 };
 
+/* Even though this is same as struct rqspinlock, we need to emit a distinct
+ * type in BTF for BPF programs.
+ */
+struct bpf_res_spin_lock {
+	u32 val;
+};
+
 struct qspinlock;
 #ifdef CONFIG_QUEUED_SPINLOCKS
 typedef struct qspinlock rqspinlock_t;
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 973a88d9b52b..e3928fb19c2c 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -30,6 +30,7 @@
 #include <linux/static_call.h>
 #include <linux/memcontrol.h>
 #include <linux/cfi.h>
+#include <asm/rqspinlock.h>
 
 struct bpf_verifier_env;
 struct bpf_verifier_log;
diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c
index ed21ee010063..b896c4a75a5c 100644
--- a/kernel/bpf/rqspinlock.c
+++ b/kernel/bpf/rqspinlock.c
@@ -15,6 +15,8 @@
 
 #include <linux/smp.h>
 #include <linux/bug.h>
+#include <linux/bpf.h>
+#include <linux/err.h>
 #include <linux/cpumask.h>
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
@@ -661,3 +663,75 @@ err_release_entry:
 EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);
 
 #endif /* CONFIG_QUEUED_SPINLOCKS */
+
+__bpf_kfunc_start_defs();
+
+__bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock)
+{
+	int ret;
+
+	BUILD_BUG_ON(sizeof(rqspinlock_t) != sizeof(struct bpf_res_spin_lock));
+	BUILD_BUG_ON(__alignof__(rqspinlock_t) != __alignof__(struct bpf_res_spin_lock));
+
+	preempt_disable();
+	ret = res_spin_lock((rqspinlock_t *)lock);
+	if (unlikely(ret)) {
+		preempt_enable();
+		return ret;
+	}
+	return 0;
+}
+
+__bpf_kfunc void bpf_res_spin_unlock(struct bpf_res_spin_lock *lock)
+{
+	res_spin_unlock((rqspinlock_t *)lock);
+	preempt_enable();
+}
+
+__bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)
+{
+	u64 *ptr = (u64 *)flags__irq_flag;
+	unsigned long flags;
+	int ret;
+
+	preempt_disable();
+	local_irq_save(flags);
+	ret = res_spin_lock((rqspinlock_t *)lock);
+	if (unlikely(ret)) {
+		local_irq_restore(flags);
+		preempt_enable();
+		return ret;
+	}
+	*ptr = flags;
+	return 0;
+}
+
+__bpf_kfunc void bpf_res_spin_unlock_irqrestore(struct bpf_res_spin_lock *lock, unsigned long *flags__irq_flag)
+{
+	u64 *ptr = (u64 *)flags__irq_flag;
+	unsigned long flags = *ptr;
+
+	res_spin_unlock((rqspinlock_t *)lock);
+	local_irq_restore(flags);
+	preempt_enable();
+}
+
+__bpf_kfunc_end_defs();
+
+BTF_KFUNCS_START(rqspinlock_kfunc_ids)
+BTF_ID_FLAGS(func, bpf_res_spin_lock, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_res_spin_unlock)
+BTF_ID_FLAGS(func, bpf_res_spin_lock_irqsave, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_res_spin_unlock_irqrestore)
+BTF_KFUNCS_END(rqspinlock_kfunc_ids)
+
+static const struct btf_kfunc_id_set rqspinlock_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set = &rqspinlock_kfunc_ids,
+};
+
+static __init int rqspinlock_register_kfuncs(void)
+{
+	return register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &rqspinlock_kfunc_set);
+}
+late_initcall(rqspinlock_register_kfuncs);