33 static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex);
37 	struct bpf_trampoline *tr = ops->private;  in bpf_tramp_ftrace_ops_func()  local
44 		lockdep_assert_held_once(&tr->mutex);  in bpf_tramp_ftrace_ops_func()
51 		if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) &&  in bpf_tramp_ftrace_ops_func()
52 		    !(tr->flags & BPF_TRAMP_F_ORIG_STACK)) {  in bpf_tramp_ftrace_ops_func()
53 			if (WARN_ON_ONCE(tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY))  in bpf_tramp_ftrace_ops_func()
56 			tr->flags |= BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
75 	if (!mutex_trylock(&tr->mutex)) {  in bpf_tramp_ftrace_ops_func()
85 		tr->flags |= BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
87 		if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) &&  in bpf_tramp_ftrace_ops_func()
88 		    !(tr->flags & BPF_TRAMP_F_ORIG_STACK))  in bpf_tramp_ftrace_ops_func()
89 			ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);  in bpf_tramp_ftrace_ops_func()
92 		tr->flags &= ~BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
94 		if (tr->flags & BPF_TRAMP_F_ORIG_STACK)  in bpf_tramp_ftrace_ops_func()
95 			ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);  in bpf_tramp_ftrace_ops_func()
102 	mutex_unlock(&tr->mutex);  in bpf_tramp_ftrace_ops_func()
136 	struct bpf_trampoline *tr;  in bpf_trampoline_lookup()  local
142 	hlist_for_each_entry(tr, head, hlist) {  in bpf_trampoline_lookup()
143 		if (tr->key == key) {  in bpf_trampoline_lookup()
144 			refcount_inc(&tr->refcnt);  in bpf_trampoline_lookup()
148 	tr = kzalloc(sizeof(*tr), GFP_KERNEL);  in bpf_trampoline_lookup()
149 	if (!tr)  in bpf_trampoline_lookup()
152 	tr->fops = kzalloc(sizeof(struct ftrace_ops), GFP_KERNEL);  in bpf_trampoline_lookup()
153 	if (!tr->fops) {  in bpf_trampoline_lookup()
154 		kfree(tr);  in bpf_trampoline_lookup()
155 		tr = NULL;  in bpf_trampoline_lookup()
158 	tr->fops->private = tr;  in bpf_trampoline_lookup()
159 	tr->fops->ops_func = bpf_tramp_ftrace_ops_func;  in bpf_trampoline_lookup()
162 	tr->key = key;  in bpf_trampoline_lookup()
163 	INIT_HLIST_NODE(&tr->hlist);  in bpf_trampoline_lookup()
164 	hlist_add_head(&tr->hlist, head);  in bpf_trampoline_lookup()
165 	refcount_set(&tr->refcnt, 1);  in bpf_trampoline_lookup()
166 	mutex_init(&tr->mutex);  in bpf_trampoline_lookup()
168 		INIT_HLIST_HEAD(&tr->progs_hlist[i]);  in bpf_trampoline_lookup()
171 	return tr;  in bpf_trampoline_lookup()
174 static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)  in unregister_fentry()  argument
176 	void *ip = tr->func.addr;  in unregister_fentry()
179 	if (tr->func.ftrace_managed)  in unregister_fentry()
180 		ret = unregister_ftrace_direct(tr->fops, (long)old_addr, false);  in unregister_fentry()
187 static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr,  in modify_fentry()  argument
190 	void *ip = tr->func.addr;  in modify_fentry()
193 	if (tr->func.ftrace_managed) {  in modify_fentry()
195 			ret = modify_ftrace_direct(tr->fops, (long)new_addr);  in modify_fentry()
197 			ret = modify_ftrace_direct_nolock(tr->fops, (long)new_addr);  in modify_fentry()
205 static int register_fentry(struct bpf_trampoline *tr, void *new_addr)  in register_fentry()  argument
207 	void *ip = tr->func.addr;  in register_fentry()
213 		if (!tr->fops)  in register_fentry()
215 		tr->func.ftrace_managed = true;  in register_fentry()
218 	if (tr->func.ftrace_managed) {  in register_fentry()
219 		ftrace_set_filter_ip(tr->fops, (unsigned long)ip, 0, 1);  in register_fentry()
220 		ret = register_ftrace_direct(tr->fops, (long)new_addr);  in register_fentry()
229 bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_arg)  in bpf_trampoline_get_progs()  argument
242 		tlinks[kind].nr_links = tr->progs_cnt[kind];  in bpf_trampoline_get_progs()
243 		*total += tr->progs_cnt[kind];  in bpf_trampoline_get_progs()
246 		hlist_for_each_entry(link, &tr->progs_hlist[kind], tramp_hlist) {  in bpf_trampoline_get_progs()
393 static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex)  in bpf_trampoline_update()  argument
397 	u32 orig_flags = tr->flags;  in bpf_trampoline_update()
401 	tlinks = bpf_trampoline_get_progs(tr, &total, &ip_arg);  in bpf_trampoline_update()
406 		err = unregister_fentry(tr, tr->cur_image->image);  in bpf_trampoline_update()
407 		bpf_tramp_image_put(tr->cur_image);  in bpf_trampoline_update()
408 		tr->cur_image = NULL;  in bpf_trampoline_update()
412 	im = bpf_tramp_image_alloc(tr->key);  in bpf_trampoline_update()
419 	tr->flags &= (BPF_TRAMP_F_SHARE_IPMODIFY | BPF_TRAMP_F_TAIL_CALL_CTX);  in bpf_trampoline_update()
426 		tr->flags |= BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME;  in bpf_trampoline_update()
428 		tr->flags |= BPF_TRAMP_F_RESTORE_REGS;  in bpf_trampoline_update()
432 		tr->flags |= BPF_TRAMP_F_IP_ARG;  in bpf_trampoline_update()
436 	if ((tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY) &&  in bpf_trampoline_update()
437 	    (tr->flags & BPF_TRAMP_F_CALL_ORIG))  in bpf_trampoline_update()
438 		tr->flags |= BPF_TRAMP_F_ORIG_STACK;  in bpf_trampoline_update()
442 					  &tr->func.model, tr->flags, tlinks,  in bpf_trampoline_update()
443 					  tr->func.addr);  in bpf_trampoline_update()
449 	WARN_ON(tr->cur_image && total == 0);  in bpf_trampoline_update()
450 	if (tr->cur_image)  in bpf_trampoline_update()
452 		err = modify_fentry(tr, tr->cur_image->image, im->image, lock_direct_mutex);  in bpf_trampoline_update()
455 		err = register_fentry(tr, im->image);  in bpf_trampoline_update()
464 		tr->fops->func = NULL;  in bpf_trampoline_update()
465 		tr->fops->trampoline = 0;  in bpf_trampoline_update()
476 	if (tr->cur_image)  in bpf_trampoline_update()
477 		bpf_tramp_image_put(tr->cur_image);  in bpf_trampoline_update()
478 	tr->cur_image = im;  in bpf_trampoline_update()
482 		tr->flags = orig_flags;  in bpf_trampoline_update()
513 static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in __bpf_trampoline_link_prog()  argument
521 	if (tr->extension_prog)  in __bpf_trampoline_link_prog()
528 		cnt += tr->progs_cnt[i];  in __bpf_trampoline_link_prog()
534 		tr->extension_prog = link->link.prog;  in __bpf_trampoline_link_prog()
535 		return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,  in __bpf_trampoline_link_prog()
543 	hlist_for_each_entry(link_exiting, &tr->progs_hlist[kind], tramp_hlist) {  in __bpf_trampoline_link_prog()
550 	hlist_add_head(&link->tramp_hlist, &tr->progs_hlist[kind]);  in __bpf_trampoline_link_prog()
551 	tr->progs_cnt[kind]++;  in __bpf_trampoline_link_prog()
552 	err = bpf_trampoline_update(tr, true /* lock_direct_mutex */);  in __bpf_trampoline_link_prog()
555 		tr->progs_cnt[kind]--;  in __bpf_trampoline_link_prog()
560 int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in bpf_trampoline_link_prog()  argument
564 	mutex_lock(&tr->mutex);  in bpf_trampoline_link_prog()
565 	err = __bpf_trampoline_link_prog(link, tr);  in bpf_trampoline_link_prog()
566 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_prog()
570 static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in __bpf_trampoline_unlink_prog()  argument
577 		WARN_ON_ONCE(!tr->extension_prog);  in __bpf_trampoline_unlink_prog()
578 		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,  in __bpf_trampoline_unlink_prog()
579 					 tr->extension_prog->bpf_func, NULL);  in __bpf_trampoline_unlink_prog()
580 		tr->extension_prog = NULL;  in __bpf_trampoline_unlink_prog()
584 	tr->progs_cnt[kind]--;  in __bpf_trampoline_unlink_prog()
585 	return bpf_trampoline_update(tr, true /* lock_direct_mutex */);  in __bpf_trampoline_unlink_prog()
589 int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in bpf_trampoline_unlink_prog()  argument
593 	mutex_lock(&tr->mutex);  in bpf_trampoline_unlink_prog()
594 	err = __bpf_trampoline_unlink_prog(link, tr);  in bpf_trampoline_unlink_prog()
595 	mutex_unlock(&tr->mutex);  in bpf_trampoline_unlink_prog()
661 static struct bpf_shim_tramp_link *cgroup_shim_find(struct bpf_trampoline *tr,  in cgroup_shim_find()  argument
668 		hlist_for_each_entry(link, &tr->progs_hlist[kind], tramp_hlist) {  in cgroup_shim_find()
684 	struct bpf_trampoline *tr;  in bpf_trampoline_link_cgroup_shim()  local
699 	tr = bpf_trampoline_get(key, &tgt_info);  in bpf_trampoline_link_cgroup_shim()
700 	if (!tr)  in bpf_trampoline_link_cgroup_shim()
703 	mutex_lock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
705 	shim_link = cgroup_shim_find(tr, bpf_func);  in bpf_trampoline_link_cgroup_shim()
710 		mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
711 		bpf_trampoline_put(tr); /* bpf_trampoline_get above */  in bpf_trampoline_link_cgroup_shim()
723 	err = __bpf_trampoline_link_prog(&shim_link->link, tr);  in bpf_trampoline_link_cgroup_shim()
727 	shim_link->trampoline = tr;  in bpf_trampoline_link_cgroup_shim()
730 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
734 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
740 	bpf_trampoline_put(tr); /* bpf_trampoline_get above */  in bpf_trampoline_link_cgroup_shim()
748 	struct bpf_trampoline *tr;  in bpf_trampoline_unlink_cgroup_shim()  local
756 	tr = bpf_trampoline_lookup(key);  in bpf_trampoline_unlink_cgroup_shim()
757 	if (WARN_ON_ONCE(!tr))  in bpf_trampoline_unlink_cgroup_shim()
760 	mutex_lock(&tr->mutex);  in bpf_trampoline_unlink_cgroup_shim()
761 	shim_link = cgroup_shim_find(tr, bpf_func);  in bpf_trampoline_unlink_cgroup_shim()
762 	mutex_unlock(&tr->mutex);  in bpf_trampoline_unlink_cgroup_shim()
767 	bpf_trampoline_put(tr); /* bpf_trampoline_lookup above */  in bpf_trampoline_unlink_cgroup_shim()
774 	struct bpf_trampoline *tr;  in bpf_trampoline_get()  local
776 	tr = bpf_trampoline_lookup(key);  in bpf_trampoline_get()
777 	if (!tr)  in bpf_trampoline_get()
780 	mutex_lock(&tr->mutex);  in bpf_trampoline_get()
781 	if (tr->func.addr)  in bpf_trampoline_get()
784 	memcpy(&tr->func.model, &tgt_info->fmodel, sizeof(tgt_info->fmodel));  in bpf_trampoline_get()
785 	tr->func.addr = (void *)tgt_info->tgt_addr;  in bpf_trampoline_get()
787 	mutex_unlock(&tr->mutex);  in bpf_trampoline_get()
788 	return tr;  in bpf_trampoline_get()
791 void bpf_trampoline_put(struct bpf_trampoline *tr)  in bpf_trampoline_put()  argument
795 	if (!tr)  in bpf_trampoline_put()
798 	if (!refcount_dec_and_test(&tr->refcnt))  in bpf_trampoline_put()
800 	WARN_ON_ONCE(mutex_is_locked(&tr->mutex));  in bpf_trampoline_put()
803 		if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[i])))  in bpf_trampoline_put()
812 	hlist_del(&tr->hlist);  in bpf_trampoline_put()
813 	if (tr->fops) {  in bpf_trampoline_put()
814 		ftrace_free_filter(tr->fops);  in bpf_trampoline_put()
815 		kfree(tr->fops);  in bpf_trampoline_put()
817 	kfree(tr);  in bpf_trampoline_put()
994 void notrace __bpf_tramp_enter(struct bpf_tramp_image *tr)  in __bpf_tramp_enter()  argument
996 	percpu_ref_get(&tr->pcref);  in __bpf_tramp_enter()
999 void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr)  in __bpf_tramp_exit()  argument
1001 	percpu_ref_put(&tr->pcref);  in __bpf_tramp_exit()
1035 arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,  in arch_prepare_bpf_trampoline()  argument