1 // SPDX-License-Identifier: GPL-2.0
3  * fprobe - Simple ftrace probe wrapper for function entry.
35 	if (fp->exit_handler) {  in __fprobe_handler()
36 		rh = rethook_try_get(fp->rethook);  in __fprobe_handler()
38 			fp->nmissed++;  in __fprobe_handler()
42 		fpr->entry_ip = ip;  in __fprobe_handler()
43 		fpr->entry_parent_ip = parent_ip;  in __fprobe_handler()
44 		if (fp->entry_data_size)  in __fprobe_handler()
45 			entry_data = fpr->data;  in __fprobe_handler()
48 	if (fp->entry_handler)  in __fprobe_handler()
49 		ret = fp->entry_handler(fp, ip, parent_ip, ftrace_get_regs(fregs), entry_data);  in __fprobe_handler()
75 		fp->nmissed++;  in fprobe_handler()
99 		fp->nmissed++;  in fprobe_kprobe_handler()
110 		fp->nmissed++;  in fprobe_kprobe_handler()
135 	 * we need to assure no calls to traceable functions in-between the  in fprobe_exit_handler()
138 	bit = ftrace_test_recursion_trylock(fpr->entry_ip, fpr->entry_parent_ip);  in fprobe_exit_handler()
140 		fp->nmissed++;  in fprobe_exit_handler()
144 	fp->exit_handler(fp, fpr->entry_ip, ret_ip, regs,  in fprobe_exit_handler()
145 			 fp->entry_data_size ? (void *)fpr->data : NULL);  in fprobe_exit_handler()
158 /* Convert ftrace location address from symbols */
166 		return ERR_PTR(-ENOMEM);  in get_ftrace_locations()
175 	return ERR_PTR(-ENOENT);  in get_ftrace_locations()
180 	fp->nmissed = 0;  in fprobe_init()
182 		fp->ops.func = fprobe_kprobe_handler;  in fprobe_init()
184 		fp->ops.func = fprobe_handler;  in fprobe_init()
185 	fp->ops.flags |= FTRACE_OPS_FL_SAVE_REGS;  in fprobe_init()
190 	int i, size;  in fprobe_init_rethook()  local
193 		return -EINVAL;  in fprobe_init_rethook()
195 	if (!fp->exit_handler) {  in fprobe_init_rethook()
196 		fp->rethook = NULL;  in fprobe_init_rethook()
201 	if (fp->nr_maxactive)  in fprobe_init_rethook()
202 		size = fp->nr_maxactive;  in fprobe_init_rethook()
204 		size = num * num_possible_cpus() * 2;  in fprobe_init_rethook()
205 	if (size <= 0)  in fprobe_init_rethook()
206 		return -EINVAL;  in fprobe_init_rethook()
208 	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler);  in fprobe_init_rethook()
209 	if (!fp->rethook)  in fprobe_init_rethook()
210 		return -ENOMEM;  in fprobe_init_rethook()
211 	for (i = 0; i < size; i++) {  in fprobe_init_rethook()
214 		node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL);  in fprobe_init_rethook()
216 			rethook_free(fp->rethook);  in fprobe_init_rethook()
217 			fp->rethook = NULL;  in fprobe_init_rethook()
218 			return -ENOMEM;  in fprobe_init_rethook()
220 		rethook_add_node(fp->rethook, &node->node);  in fprobe_init_rethook()
227 	if (fp->rethook) {  in fprobe_fail_cleanup()
228 		/* Don't need to cleanup rethook->handler because this is not used. */  in fprobe_fail_cleanup()
229 		rethook_free(fp->rethook);  in fprobe_fail_cleanup()
230 		fp->rethook = NULL;  in fprobe_fail_cleanup()
232 	ftrace_free_filter(&fp->ops);  in fprobe_fail_cleanup()
236  * register_fprobe() - Register fprobe to ftrace by pattern.
241  * Register @fp to ftrace for enabling the probe on the symbols matched to @filter.
244  * Return 0 if @fp is registered successfully, -errno if not.
253 		return -EINVAL;  in register_fprobe()
259 	ret = ftrace_set_filter(&fp->ops, str, len, 0);  in register_fprobe()
267 		ret = ftrace_set_notrace(&fp->ops, str, len, 0);  in register_fprobe()
277 	hash = rcu_access_pointer(fp->ops.local_hash.filter_hash);  in register_fprobe()
281 	ret = fprobe_init_rethook(fp, (int)hash->count);  in register_fprobe()
283 		ret = register_ftrace_function(&fp->ops);  in register_fprobe()
293  * register_fprobe_ips() - Register fprobe to ftrace by address.
295  * @addrs: An array of target ftrace location addresses.
298  * Register @fp to ftrace for enabling the probe on the address given by @addrs.
299  * The @addrs must be the addresses of ftrace location address, which may be
300  * the symbol address + arch-dependent offset.
303  * Return 0 if @fp is registered successfully, -errno if not.
310 		return -EINVAL;  in register_fprobe_ips()
314 	ret = ftrace_set_filter_ips(&fp->ops, addrs, num, 0, 0);  in register_fprobe_ips()
320 		ret = register_ftrace_function(&fp->ops);  in register_fprobe_ips()
329  * register_fprobe_syms() - Register fprobe to ftrace by symbols.
337  * Return 0 if @fp is registered successfully, -errno if not.
345 		return -EINVAL;  in register_fprobe_syms()
361 	if (!fp || (fp->ops.saved_func != fprobe_handler &&  in fprobe_is_registered()
362 		    fp->ops.saved_func != fprobe_kprobe_handler))  in fprobe_is_registered()
368  * unregister_fprobe() - Unregister fprobe from ftrace
371  * Unregister fprobe (and remove ftrace hooks from the function entries).
373  * Return 0 if @fp is unregistered successfully, -errno if not.
380 		return -EINVAL;  in unregister_fprobe()
382 	if (fp->rethook)  in unregister_fprobe()
383 		rethook_stop(fp->rethook);  in unregister_fprobe()
385 	ret = unregister_ftrace_function(&fp->ops);  in unregister_fprobe()
389 	if (fp->rethook)  in unregister_fprobe()
390 		rethook_free(fp->rethook);  in unregister_fprobe()
392 	ftrace_free_filter(&fp->ops);  in unregister_fprobe()