linux-master/kernel/rseq.c

40  *                     init(rseq_cs)
42  *   [1]               TLS->rseq::rseq_cs = rseq_cs
58  *   1.  Userspace stores the address of the struct rseq_cs assembly
59  *       block descriptor into the rseq_cs field of the registered
70  *       clears TLS->__rseq_abi::rseq_cs, and sets the user-space return
152 static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
154 	struct rseq_cs __user *urseq_cs;
161 	if (get_user(ptr, &t->rseq->rseq_cs))
164 	if (copy_from_user(&ptr, &t->rseq->rseq_cs, sizeof(ptr)))
168 		memset(rseq_cs, 0, sizeof(*rseq_cs));
173 	urseq_cs = (struct rseq_cs __user *)(unsigned long)ptr;
174 	if (copy_from_user(rseq_cs, urseq_cs, sizeof(*rseq_cs)))
177 	if (rseq_cs->start_ip >= TASK_SIZE ||
178 	    rseq_cs->start_ip + rseq_cs->post_commit_offset >= TASK_SIZE ||
179 	    rseq_cs->abort_ip >= TASK_SIZE ||
180 	    rseq_cs->version > 0)
183 	if (rseq_cs->start_ip + rseq_cs->post_commit_offset < rseq_cs->start_ip)
186 	if (rseq_cs->abort_ip - rseq_cs->start_ip < rseq_cs->post_commit_offset)
189 	usig = (u32 __user *)(unsigned long)(rseq_cs->abort_ip - sizeof(u32));
223 	if (rseq_warn_flags("rseq_cs", cs_flags))
249 	 * The rseq_cs field is set to NULL on preemption or signal
252 	 * a lazy clear of the rseq_cs field.
254 	 * Set rseq_cs to NULL.
257 	return put_user(0UL, &t->rseq->rseq_cs);
259 	if (clear_user(&t->rseq->rseq_cs, sizeof(t->rseq->rseq_cs)))
269 static bool in_rseq_cs(unsigned long ip, struct rseq_cs *rseq_cs)
271 	return ip - rseq_cs->start_ip < rseq_cs->post_commit_offset;
278 	struct rseq_cs rseq_cs;
281 	ret = rseq_get_rseq_cs(t, &rseq_cs);
288 	 * Clear the rseq_cs pointer and return.
290 	if (!in_rseq_cs(ip, &rseq_cs))
292 	ret = rseq_need_restart(t, rseq_cs.flags);
298 	trace_rseq_ip_fixup(ip, rseq_cs.start_ip, rseq_cs.post_commit_offset,
299 			    rseq_cs.abort_ip);
300 	instruction_pointer_set(regs, (unsigned long)rseq_cs.abort_ip);
325 	 * fixup and leave rseq_cs as is so that rseq_sycall() will detect and
352 	struct rseq_cs rseq_cs;
356 	if (rseq_get_rseq_cs(t, &rseq_cs) || in_rseq_cs(ip, &rseq_cs))