bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/io_uring/sqpoll.h b/io_uring/sqpoll.h
new file mode 100644
index 000000000..fd2f6f29b
--- /dev/null
+++ b/io_uring/sqpoll.h
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+
+struct io_sq_data {
+	refcount_t		refs;
+	atomic_t		park_pending;
+	struct mutex		lock;
+
+	/* ctx's that are using this sqd */
+	struct list_head	ctx_list;
+
+	struct task_struct __rcu *thread;
+	struct wait_queue_head	wait;
+
+	unsigned		sq_thread_idle;
+	int			sq_cpu;
+	pid_t			task_pid;
+	pid_t			task_tgid;
+
+	u64			work_time;
+	unsigned long		state;
+	struct completion	exited;
+};
+
+int io_sq_offload_create(struct io_ring_ctx *ctx, struct io_uring_params *p);
+void io_sq_thread_finish(struct io_ring_ctx *ctx);
+void io_sq_thread_stop(struct io_sq_data *sqd);
+void io_sq_thread_park(struct io_sq_data *sqd);
+void io_sq_thread_unpark(struct io_sq_data *sqd);
+void io_put_sq_data(struct io_sq_data *sqd);
+void io_sqpoll_wait_sq(struct io_ring_ctx *ctx);
+int io_sqpoll_wq_cpu_affinity(struct io_ring_ctx *ctx, cpumask_var_t mask);
+u64 io_sq_cpu_usec(struct task_struct *tsk);
+
+static inline struct task_struct *sqpoll_task_locked(struct io_sq_data *sqd)
+{
+	return rcu_dereference_protected(sqd->thread,
+					 lockdep_is_held(&sqd->lock));
+}