xref: /openbmc/u-boot/common/log.c (revision 44262327)
1 /*
2  * Logging support
3  *
4  * Copyright (c) 2017 Google, Inc
5  * Written by Simon Glass <sjg@chromium.org>
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <log.h>
12 #include <malloc.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 static struct log_device *log_device_find_by_name(const char *drv_name)
17 {
18 	struct log_device *ldev;
19 
20 	list_for_each_entry(ldev, &gd->log_head, sibling_node) {
21 		if (!strcmp(drv_name, ldev->drv->name))
22 			return ldev;
23 	}
24 
25 	return NULL;
26 }
27 
28 /**
29  * log_has_cat() - check if a log category exists within a list
30  *
31  * @cat_list: List of categories to check, at most LOGF_MAX_CATEGORIES entries
32  *	long, terminated by LC_END if fewer
33  * @cat: Category to search for
34  * @return true if @cat is in @cat_list, else false
35  */
36 static bool log_has_cat(enum log_category_t cat_list[], enum log_category_t cat)
37 {
38 	int i;
39 
40 	for (i = 0; i < LOGF_MAX_CATEGORIES && cat_list[i] != LOGC_END; i++) {
41 		if (cat_list[i] == cat)
42 			return true;
43 	}
44 
45 	return false;
46 }
47 
48 /**
49  * log_has_file() - check if a file is with a list
50  *
51  * @file_list: List of files to check, separated by comma
52  * @file: File to check for. This string is matched against the end of each
53  *	file in the list, i.e. ignoring any preceding path. The list is
54  *	intended to consist of relative pathnames, e.g. common/main.c,cmd/log.c
55  * @return true if @file is in @file_list, else false
56  */
57 static bool log_has_file(const char *file_list, const char *file)
58 {
59 	int file_len = strlen(file);
60 	const char *s, *p;
61 	int substr_len;
62 
63 	for (s = file_list; *s; s = p + (*p != '\0')) {
64 		p = strchrnul(s, ',');
65 		substr_len = p - s;
66 		if (file_len >= substr_len &&
67 		    !strncmp(file + file_len - substr_len, s, substr_len))
68 			return true;
69 	}
70 
71 	return false;
72 }
73 
74 /**
75  * log_passes_filters() - check if a log record passes the filters for a device
76  *
77  * @ldev: Log device to check
78  * @rec: Log record to check
79  * @return true if @rec is not blocked by the filters in @ldev, false if it is
80  */
81 static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec)
82 {
83 	struct log_filter *filt;
84 
85 	/* If there are no filters, filter on the default log level */
86 	if (list_empty(&ldev->filter_head)) {
87 		if (rec->level > gd->default_log_level)
88 			return false;
89 		return true;
90 	}
91 
92 	list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
93 		if (rec->level > filt->max_level)
94 			continue;
95 		if ((filt->flags & LOGFF_HAS_CAT) &&
96 		    !log_has_cat(filt->cat_list, rec->cat))
97 			continue;
98 		if (filt->file_list &&
99 		    !log_has_file(filt->file_list, rec->file))
100 			continue;
101 		return true;
102 	}
103 
104 	return false;
105 }
106 
107 /**
108  * log_dispatch() - Send a log record to all log devices for processing
109  *
110  * The log record is sent to each log device in turn, skipping those which have
111  * filters which block the record
112  *
113  * @rec: Log record to dispatch
114  * @return 0 (meaning success)
115  */
116 static int log_dispatch(struct log_rec *rec)
117 {
118 	struct log_device *ldev;
119 
120 	list_for_each_entry(ldev, &gd->log_head, sibling_node) {
121 		if (log_passes_filters(ldev, rec))
122 			ldev->drv->emit(ldev, rec);
123 	}
124 
125 	return 0;
126 }
127 
128 int _log(enum log_category_t cat, enum log_level_t level, const char *file,
129 	 int line, const char *func, const char *fmt, ...)
130 {
131 	char buf[CONFIG_SYS_CBSIZE];
132 	struct log_rec rec;
133 	va_list args;
134 
135 	rec.cat = cat;
136 	rec.level = level;
137 	rec.file = file;
138 	rec.line = line;
139 	rec.func = func;
140 	va_start(args, fmt);
141 	vsnprintf(buf, sizeof(buf), fmt, args);
142 	va_end(args);
143 	rec.msg = buf;
144 	if (!gd || !(gd->flags & GD_FLG_LOG_READY)) {
145 		if (gd)
146 			gd->log_drop_count++;
147 		return -ENOSYS;
148 	}
149 	log_dispatch(&rec);
150 
151 	return 0;
152 }
153 
154 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
155 		   enum log_level_t max_level, const char *file_list)
156 {
157 	struct log_filter *filt;
158 	struct log_device *ldev;
159 	int i;
160 
161 	ldev = log_device_find_by_name(drv_name);
162 	if (!ldev)
163 		return -ENOENT;
164 	filt = (struct log_filter *)calloc(1, sizeof(*filt));
165 	if (!filt)
166 		return -ENOMEM;
167 
168 	if (cat_list) {
169 		filt->flags |= LOGFF_HAS_CAT;
170 		for (i = 0; ; i++) {
171 			if (i == ARRAY_SIZE(filt->cat_list))
172 				return -ENOSPC;
173 			filt->cat_list[i] = cat_list[i];
174 			if (cat_list[i] == LOGC_END)
175 				break;
176 		}
177 	}
178 	filt->max_level = max_level;
179 	if (file_list) {
180 		filt->file_list = strdup(file_list);
181 		if (!filt->file_list)
182 			goto nomem;
183 	}
184 	filt->filter_num = ldev->next_filter_num++;
185 	list_add_tail(&filt->sibling_node, &ldev->filter_head);
186 
187 	return filt->filter_num;
188 
189 nomem:
190 	free(filt);
191 	return -ENOMEM;
192 }
193 
194 int log_remove_filter(const char *drv_name, int filter_num)
195 {
196 	struct log_filter *filt;
197 	struct log_device *ldev;
198 
199 	ldev = log_device_find_by_name(drv_name);
200 	if (!ldev)
201 		return -ENOENT;
202 
203 	list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
204 		if (filt->filter_num == filter_num) {
205 			list_del(&filt->sibling_node);
206 			free(filt);
207 
208 			return 0;
209 		}
210 	}
211 
212 	return -ENOENT;
213 }
214 
215 int log_init(void)
216 {
217 	struct log_driver *drv = ll_entry_start(struct log_driver, log_driver);
218 	const int count = ll_entry_count(struct log_driver, log_driver);
219 	struct log_driver *end = drv + count;
220 
221 	/*
222 	 * We cannot add runtime data to the driver since it is likely stored
223 	 * in rodata. Instead, set up a 'device' corresponding to each driver.
224 	 * We only support having a single device.
225 	 */
226 	INIT_LIST_HEAD((struct list_head *)&gd->log_head);
227 	while (drv < end) {
228 		struct log_device *ldev;
229 
230 		ldev = calloc(1, sizeof(*ldev));
231 		if (!ldev) {
232 			debug("%s: Cannot allocate memory\n", __func__);
233 			return -ENOMEM;
234 		}
235 		INIT_LIST_HEAD(&ldev->filter_head);
236 		ldev->drv = drv;
237 		list_add_tail(&ldev->sibling_node,
238 			      (struct list_head *)&gd->log_head);
239 		drv++;
240 	}
241 	gd->flags |= GD_FLG_LOG_READY;
242 	gd->default_log_level = LOGL_INFO;
243 
244 	return 0;
245 }
246