1 // SPDX-License-Identifier: GPL-2.0
3  * fprobe - Simple ftrace probe wrapper for function entry.
36 		fp->nmissed++;  in fprobe_handler()
40 	if (fp->entry_handler)  in fprobe_handler()
41 		fp->entry_handler(fp, ip, ftrace_get_regs(fregs));  in fprobe_handler()
43 	if (fp->exit_handler) {  in fprobe_handler()
44 		rh = rethook_try_get(fp->rethook);  in fprobe_handler()
46 			fp->nmissed++;  in fprobe_handler()
50 		fpr->entry_ip = ip;  in fprobe_handler()
65 		fp->nmissed++;  in fprobe_kprobe_handler()
84 	fp->exit_handler(fp, fpr->entry_ip, regs);  in fprobe_exit_handler()
97 static unsigned long *get_ftrace_locations(const char **syms, int num)  in get_ftrace_locations()  argument
102 	addrs = kcalloc(num, sizeof(*addrs), GFP_KERNEL);  in get_ftrace_locations()
104 		return ERR_PTR(-ENOMEM);  in get_ftrace_locations()
107 	sort(syms, num, sizeof(*syms), symbols_cmp, NULL);  in get_ftrace_locations()
109 	if (!ftrace_lookup_symbols(syms, num, addrs))  in get_ftrace_locations()
113 	return ERR_PTR(-ENOENT);  in get_ftrace_locations()
118 	fp->nmissed = 0;  in fprobe_init()
120 		fp->ops.func = fprobe_kprobe_handler;  in fprobe_init()
122 		fp->ops.func = fprobe_handler;  in fprobe_init()
123 	fp->ops.flags |= FTRACE_OPS_FL_SAVE_REGS;  in fprobe_init()
126 static int fprobe_init_rethook(struct fprobe *fp, int num)  in fprobe_init_rethook()  argument
130 	if (num < 0)  in fprobe_init_rethook()
131 		return -EINVAL;  in fprobe_init_rethook()
133 	if (!fp->exit_handler) {  in fprobe_init_rethook()
134 		fp->rethook = NULL;  in fprobe_init_rethook()
139 	size = num * num_possible_cpus() * 2;  in fprobe_init_rethook()
141 		return -E2BIG;  in fprobe_init_rethook()
143 	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler);  in fprobe_init_rethook()
144 	if (!fp->rethook)  in fprobe_init_rethook()
145 		return -ENOMEM;  in fprobe_init_rethook()
151 			rethook_free(fp->rethook);  in fprobe_init_rethook()
152 			fp->rethook = NULL;  in fprobe_init_rethook()
153 			return -ENOMEM;  in fprobe_init_rethook()
155 		rethook_add_node(fp->rethook, &node->node);  in fprobe_init_rethook()
162 	if (fp->rethook) {  in fprobe_fail_cleanup()
163 		/* Don't need to cleanup rethook->handler because this is not used. */  in fprobe_fail_cleanup()
164 		rethook_free(fp->rethook);  in fprobe_fail_cleanup()
165 		fp->rethook = NULL;  in fprobe_fail_cleanup()
167 	ftrace_free_filter(&fp->ops);  in fprobe_fail_cleanup()
171  * register_fprobe() - Register fprobe to ftrace by pattern.
179  * Return 0 if @fp is registered successfully, -errno if not.
188 		return -EINVAL;  in register_fprobe()
194 	ret = ftrace_set_filter(&fp->ops, str, len, 0);  in register_fprobe()
202 		ret = ftrace_set_notrace(&fp->ops, str, len, 0);  in register_fprobe()
212 	hash = rcu_access_pointer(fp->ops.local_hash.filter_hash);  in register_fprobe()
216 	ret = fprobe_init_rethook(fp, (int)hash->count);  in register_fprobe()
218 		ret = register_ftrace_function(&fp->ops);  in register_fprobe()
228  * register_fprobe_ips() - Register fprobe to ftrace by address.
230  * @addrs: An array of target ftrace location addresses.
231  * @num: The number of entries of @addrs.
234  * The @addrs must be the addresses of ftrace location address, which may be
235  * the symbol address + arch-dependent offset.
238  * Return 0 if @fp is registered successfully, -errno if not.
240 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)  in register_fprobe_ips()  argument
244 	if (!fp || !addrs || num <= 0)  in register_fprobe_ips()
245 		return -EINVAL;  in register_fprobe_ips()
249 	ret = ftrace_set_filter_ips(&fp->ops, addrs, num, 0, 0);  in register_fprobe_ips()
253 	ret = fprobe_init_rethook(fp, num);  in register_fprobe_ips()
255 		ret = register_ftrace_function(&fp->ops);  in register_fprobe_ips()
264  * register_fprobe_syms() - Register fprobe to ftrace by symbols.
267  * @num: The number of entries of @syms.
272  * Return 0 if @fp is registered successfully, -errno if not.
274 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)  in register_fprobe_syms()  argument
279 	if (!fp || !syms || num <= 0)  in register_fprobe_syms()
280 		return -EINVAL;  in register_fprobe_syms()
282 	addrs = get_ftrace_locations(syms, num);  in register_fprobe_syms()
286 	ret = register_fprobe_ips(fp, addrs, num);  in register_fprobe_syms()
295  * unregister_fprobe() - Unregister fprobe from ftrace
300  * Return 0 if @fp is unregistered successfully, -errno if not.
306 	if (!fp || (fp->ops.saved_func != fprobe_handler &&  in unregister_fprobe()
307 		    fp->ops.saved_func != fprobe_kprobe_handler))  in unregister_fprobe()
308 		return -EINVAL;  in unregister_fprobe()
316 	if (fp->rethook)  in unregister_fprobe()
317 		rethook_free(fp->rethook);  in unregister_fprobe()
319 	ret = unregister_ftrace_function(&fp->ops);  in unregister_fprobe()
323 	ftrace_free_filter(&fp->ops);  in unregister_fprobe()