34 static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex);
38 	struct bpf_trampoline *tr = ops->private;  in bpf_tramp_ftrace_ops_func()  local
45 		lockdep_assert_held_once(&tr->mutex);  in bpf_tramp_ftrace_ops_func()
52 		if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) &&  in bpf_tramp_ftrace_ops_func()
53 		    !(tr->flags & BPF_TRAMP_F_ORIG_STACK)) {  in bpf_tramp_ftrace_ops_func()
54 			if (WARN_ON_ONCE(tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY))  in bpf_tramp_ftrace_ops_func()
57 			tr->flags |= BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
76 	if (!mutex_trylock(&tr->mutex)) {  in bpf_tramp_ftrace_ops_func()
86 		tr->flags |= BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
88 		if ((tr->flags & BPF_TRAMP_F_CALL_ORIG) &&  in bpf_tramp_ftrace_ops_func()
89 		    !(tr->flags & BPF_TRAMP_F_ORIG_STACK))  in bpf_tramp_ftrace_ops_func()
90 			ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);  in bpf_tramp_ftrace_ops_func()
93 		tr->flags &= ~BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_tramp_ftrace_ops_func()
95 		if (tr->flags & BPF_TRAMP_F_ORIG_STACK)  in bpf_tramp_ftrace_ops_func()
96 			ret = bpf_trampoline_update(tr, false /* lock_direct_mutex */);  in bpf_tramp_ftrace_ops_func()
103 	mutex_unlock(&tr->mutex);  in bpf_tramp_ftrace_ops_func()
137 	struct bpf_trampoline *tr;  in bpf_trampoline_lookup()  local
143 	hlist_for_each_entry(tr, head, hlist) {  in bpf_trampoline_lookup()
144 		if (tr->key == key) {  in bpf_trampoline_lookup()
145 			refcount_inc(&tr->refcnt);  in bpf_trampoline_lookup()
149 	tr = kzalloc(sizeof(*tr), GFP_KERNEL);  in bpf_trampoline_lookup()
150 	if (!tr)  in bpf_trampoline_lookup()
153 	tr->fops = kzalloc(sizeof(struct ftrace_ops), GFP_KERNEL);  in bpf_trampoline_lookup()
154 	if (!tr->fops) {  in bpf_trampoline_lookup()
155 		kfree(tr);  in bpf_trampoline_lookup()
156 		tr = NULL;  in bpf_trampoline_lookup()
159 	tr->fops->private = tr;  in bpf_trampoline_lookup()
160 	tr->fops->ops_func = bpf_tramp_ftrace_ops_func;  in bpf_trampoline_lookup()
163 	tr->key = key;  in bpf_trampoline_lookup()
164 	INIT_HLIST_NODE(&tr->hlist);  in bpf_trampoline_lookup()
165 	hlist_add_head(&tr->hlist, head);  in bpf_trampoline_lookup()
166 	refcount_set(&tr->refcnt, 1);  in bpf_trampoline_lookup()
167 	mutex_init(&tr->mutex);  in bpf_trampoline_lookup()
169 		INIT_HLIST_HEAD(&tr->progs_hlist[i]);  in bpf_trampoline_lookup()
172 	return tr;  in bpf_trampoline_lookup()
175 static int bpf_trampoline_module_get(struct bpf_trampoline *tr)  in bpf_trampoline_module_get()  argument
181 	mod = __module_text_address((unsigned long) tr->func.addr);  in bpf_trampoline_module_get()
185 	tr->mod = mod;  in bpf_trampoline_module_get()
189 static void bpf_trampoline_module_put(struct bpf_trampoline *tr)  in bpf_trampoline_module_put()  argument
191 	module_put(tr->mod);  in bpf_trampoline_module_put()
192 	tr->mod = NULL;  in bpf_trampoline_module_put()
195 static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)  in unregister_fentry()  argument
197 	void *ip = tr->func.addr;  in unregister_fentry()
200 	if (tr->func.ftrace_managed)  in unregister_fentry()
201 		ret = unregister_ftrace_direct_multi(tr->fops, (long)old_addr);  in unregister_fentry()
206 		bpf_trampoline_module_put(tr);  in unregister_fentry()
210 static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr,  in modify_fentry()  argument
213 	void *ip = tr->func.addr;  in modify_fentry()
216 	if (tr->func.ftrace_managed) {  in modify_fentry()
218 			ret = modify_ftrace_direct_multi(tr->fops, (long)new_addr);  in modify_fentry()
220 			ret = modify_ftrace_direct_multi_nolock(tr->fops, (long)new_addr);  in modify_fentry()
228 static int register_fentry(struct bpf_trampoline *tr, void *new_addr)  in register_fentry()  argument
230 	void *ip = tr->func.addr;  in register_fentry()
236 		if (!tr->fops)  in register_fentry()
238 		tr->func.ftrace_managed = true;  in register_fentry()
241 	if (bpf_trampoline_module_get(tr))  in register_fentry()
244 	if (tr->func.ftrace_managed) {  in register_fentry()
245 		ftrace_set_filter_ip(tr->fops, (unsigned long)ip, 0, 1);  in register_fentry()
246 		ret = register_ftrace_direct_multi(tr->fops, (long)new_addr);  in register_fentry()
252 		bpf_trampoline_module_put(tr);  in register_fentry()
257 bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_arg)  in bpf_trampoline_get_progs()  argument
270 		tlinks[kind].nr_links = tr->progs_cnt[kind];  in bpf_trampoline_get_progs()
271 		*total += tr->progs_cnt[kind];  in bpf_trampoline_get_progs()
274 		hlist_for_each_entry(link, &tr->progs_hlist[kind], tramp_hlist) {  in bpf_trampoline_get_progs()
416 static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex)  in bpf_trampoline_update()  argument
420 	u32 orig_flags = tr->flags;  in bpf_trampoline_update()
424 	tlinks = bpf_trampoline_get_progs(tr, &total, &ip_arg);  in bpf_trampoline_update()
429 		err = unregister_fentry(tr, tr->cur_image->image);  in bpf_trampoline_update()
430 		bpf_tramp_image_put(tr->cur_image);  in bpf_trampoline_update()
431 		tr->cur_image = NULL;  in bpf_trampoline_update()
432 		tr->selector = 0;  in bpf_trampoline_update()
436 	im = bpf_tramp_image_alloc(tr->key, tr->selector);  in bpf_trampoline_update()
443 	tr->flags &= BPF_TRAMP_F_SHARE_IPMODIFY;  in bpf_trampoline_update()
450 		tr->flags |= BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME;  in bpf_trampoline_update()
452 		tr->flags |= BPF_TRAMP_F_RESTORE_REGS;  in bpf_trampoline_update()
456 		tr->flags |= BPF_TRAMP_F_IP_ARG;  in bpf_trampoline_update()
460 	if ((tr->flags & BPF_TRAMP_F_SHARE_IPMODIFY) &&  in bpf_trampoline_update()
461 	    (tr->flags & BPF_TRAMP_F_CALL_ORIG))  in bpf_trampoline_update()
462 		tr->flags |= BPF_TRAMP_F_ORIG_STACK;  in bpf_trampoline_update()
466 					  &tr->func.model, tr->flags, tlinks,  in bpf_trampoline_update()
467 					  tr->func.addr);  in bpf_trampoline_update()
474 	WARN_ON(tr->cur_image && tr->selector == 0);  in bpf_trampoline_update()
475 	WARN_ON(!tr->cur_image && tr->selector);  in bpf_trampoline_update()
476 	if (tr->cur_image)  in bpf_trampoline_update()
478 		err = modify_fentry(tr, tr->cur_image->image, im->image, lock_direct_mutex);  in bpf_trampoline_update()
481 		err = register_fentry(tr, im->image);  in bpf_trampoline_update()
490 		tr->fops->func = NULL;  in bpf_trampoline_update()
491 		tr->fops->trampoline = 0;  in bpf_trampoline_update()
502 	if (tr->cur_image)  in bpf_trampoline_update()
503 		bpf_tramp_image_put(tr->cur_image);  in bpf_trampoline_update()
504 	tr->cur_image = im;  in bpf_trampoline_update()
505 	tr->selector++;  in bpf_trampoline_update()
509 		tr->flags = orig_flags;  in bpf_trampoline_update()
536 static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in __bpf_trampoline_link_prog()  argument
544 	if (tr->extension_prog)  in __bpf_trampoline_link_prog()
551 		cnt += tr->progs_cnt[i];  in __bpf_trampoline_link_prog()
557 		tr->extension_prog = link->link.prog;  in __bpf_trampoline_link_prog()
558 		return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,  in __bpf_trampoline_link_prog()
566 	hlist_for_each_entry(link_exiting, &tr->progs_hlist[kind], tramp_hlist) {  in __bpf_trampoline_link_prog()
573 	hlist_add_head(&link->tramp_hlist, &tr->progs_hlist[kind]);  in __bpf_trampoline_link_prog()
574 	tr->progs_cnt[kind]++;  in __bpf_trampoline_link_prog()
575 	err = bpf_trampoline_update(tr, true /* lock_direct_mutex */);  in __bpf_trampoline_link_prog()
578 		tr->progs_cnt[kind]--;  in __bpf_trampoline_link_prog()
583 int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in bpf_trampoline_link_prog()  argument
587 	mutex_lock(&tr->mutex);  in bpf_trampoline_link_prog()
588 	err = __bpf_trampoline_link_prog(link, tr);  in bpf_trampoline_link_prog()
589 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_prog()
593 static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in __bpf_trampoline_unlink_prog()  argument
600 		WARN_ON_ONCE(!tr->extension_prog);  in __bpf_trampoline_unlink_prog()
601 		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,  in __bpf_trampoline_unlink_prog()
602 					 tr->extension_prog->bpf_func, NULL);  in __bpf_trampoline_unlink_prog()
603 		tr->extension_prog = NULL;  in __bpf_trampoline_unlink_prog()
607 	tr->progs_cnt[kind]--;  in __bpf_trampoline_unlink_prog()
608 	return bpf_trampoline_update(tr, true /* lock_direct_mutex */);  in __bpf_trampoline_unlink_prog()
612 int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)  in bpf_trampoline_unlink_prog()  argument
616 	mutex_lock(&tr->mutex);  in bpf_trampoline_unlink_prog()
617 	err = __bpf_trampoline_unlink_prog(link, tr);  in bpf_trampoline_unlink_prog()
618 	mutex_unlock(&tr->mutex);  in bpf_trampoline_unlink_prog()
684 static struct bpf_shim_tramp_link *cgroup_shim_find(struct bpf_trampoline *tr,  in cgroup_shim_find()  argument
691 		hlist_for_each_entry(link, &tr->progs_hlist[kind], tramp_hlist) {  in cgroup_shim_find()
707 	struct bpf_trampoline *tr;  in bpf_trampoline_link_cgroup_shim()  local
722 	tr = bpf_trampoline_get(key, &tgt_info);  in bpf_trampoline_link_cgroup_shim()
723 	if (!tr)  in bpf_trampoline_link_cgroup_shim()
726 	mutex_lock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
728 	shim_link = cgroup_shim_find(tr, bpf_func);  in bpf_trampoline_link_cgroup_shim()
733 		mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
734 		bpf_trampoline_put(tr); /* bpf_trampoline_get above */  in bpf_trampoline_link_cgroup_shim()
746 	err = __bpf_trampoline_link_prog(&shim_link->link, tr);  in bpf_trampoline_link_cgroup_shim()
750 	shim_link->trampoline = tr;  in bpf_trampoline_link_cgroup_shim()
753 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
757 	mutex_unlock(&tr->mutex);  in bpf_trampoline_link_cgroup_shim()
763 	bpf_trampoline_put(tr); /* bpf_trampoline_get above */  in bpf_trampoline_link_cgroup_shim()
771 	struct bpf_trampoline *tr;  in bpf_trampoline_unlink_cgroup_shim()  local
779 	tr = bpf_trampoline_lookup(key);  in bpf_trampoline_unlink_cgroup_shim()
780 	if (WARN_ON_ONCE(!tr))  in bpf_trampoline_unlink_cgroup_shim()
783 	mutex_lock(&tr->mutex);  in bpf_trampoline_unlink_cgroup_shim()
784 	shim_link = cgroup_shim_find(tr, bpf_func);  in bpf_trampoline_unlink_cgroup_shim()
785 	mutex_unlock(&tr->mutex);  in bpf_trampoline_unlink_cgroup_shim()
790 	bpf_trampoline_put(tr); /* bpf_trampoline_lookup above */  in bpf_trampoline_unlink_cgroup_shim()
797 	struct bpf_trampoline *tr;  in bpf_trampoline_get()  local
799 	tr = bpf_trampoline_lookup(key);  in bpf_trampoline_get()
800 	if (!tr)  in bpf_trampoline_get()
803 	mutex_lock(&tr->mutex);  in bpf_trampoline_get()
804 	if (tr->func.addr)  in bpf_trampoline_get()
807 	memcpy(&tr->func.model, &tgt_info->fmodel, sizeof(tgt_info->fmodel));  in bpf_trampoline_get()
808 	tr->func.addr = (void *)tgt_info->tgt_addr;  in bpf_trampoline_get()
810 	mutex_unlock(&tr->mutex);  in bpf_trampoline_get()
811 	return tr;  in bpf_trampoline_get()
814 void bpf_trampoline_put(struct bpf_trampoline *tr)  in bpf_trampoline_put()  argument
818 	if (!tr)  in bpf_trampoline_put()
821 	if (!refcount_dec_and_test(&tr->refcnt))  in bpf_trampoline_put()
823 	WARN_ON_ONCE(mutex_is_locked(&tr->mutex));  in bpf_trampoline_put()
826 		if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[i])))  in bpf_trampoline_put()
835 	hlist_del(&tr->hlist);  in bpf_trampoline_put()
836 	if (tr->fops) {  in bpf_trampoline_put()
837 		ftrace_free_filter(tr->fops);  in bpf_trampoline_put()
838 		kfree(tr->fops);  in bpf_trampoline_put()
840 	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()
1005 arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,  in arch_prepare_bpf_trampoline()  argument