| 1 | |
| 2 | * lib/dynamic_debug.c
|
| 3 | *
|
| 4 | * make pr_debug()/dev_dbg() calls runtime configurable based upon their
|
| 5 | * source module.
|
| 6 | *
|
| 7 | * Copyright (C) 2008 Jason Baron <[email protected]>
|
| 8 | * By Greg Banks <[email protected]>
|
| 9 | * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved.
|
| 10 |
|
| 11 |
|
| 12 | #include <linux/kernel.h>
|
| 13 | #include <linux/module.h>
|
| 14 | #include <linux/moduleparam.h>
|
| 15 | #include <linux/kallsyms.h>
|
| 16 | #include <linux/version.h>
|
| 17 | #include <linux/types.h>
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| 18 | #include <linux/mutex.h>
|
| 19 | #include <linux/proc_fs.h>
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| 20 | #include <linux/seq_file.h>
|
| 21 | #include <linux/list.h>
|
| 22 | #include <linux/sysctl.h>
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| 23 | #include <linux/ctype.h>
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| 24 | #include <linux/string.h>
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| 25 | #include <linux/uaccess.h>
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| 26 | #include <linux/dynamic_debug.h>
|
| 27 | #include <linux/debugfs.h>
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| 28 | #include <linux/slab.h>
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| 29 | #include <linux/jump_label.h>
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| 30 |
|
| 31 | extern struct _ddebug __start___verbose[];
|
| 32 | extern struct _ddebug __stop___verbose[];
|
| 33 |
|
| 34 | struct ddebug_table {
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| 35 | struct list_head link;
|
| 36 | char *mod_name;
|
| 37 | unsigned int num_ddebugs;
|
| 38 | unsigned int num_enabled;
|
| 39 | struct _ddebug *ddebugs;
|
| 40 | };
|
| 41 |
|
| 42 | struct ddebug_query {
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| 43 | const char *filename;
|
| 44 | const char *module;
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| 45 | const char *function;
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| 46 | const char *format;
|
| 47 | unsigned int first_lineno, last_lineno;
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| 48 | };
|
| 49 |
|
| 50 | struct ddebug_iter {
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| 51 | struct ddebug_table *table;
|
| 52 | unsigned int idx;
|
| 53 | };
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| 54 |
|
| 55 | static DEFINE_MUTEX(ddebug_lock);
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| 56 | static LIST_HEAD(ddebug_tables);
|
| 57 | static int verbose = 0;
|
| 58 |
|
| 59 |
|
| 60 | static inline const char *basename(const char *path)
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| 61 | {
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| 62 | const char *tail = strrchr(path, '/');
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| 63 | return tail ? tail+1 : path;
|
| 64 | }
|
| 65 |
|
| 66 |
|
| 67 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
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| 68 | size_t maxlen)
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| 69 | {
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| 70 | char *p = buf;
|
| 71 |
|
| 72 | BUG_ON(maxlen < 4);
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| 73 | if (dp->flags & _DPRINTK_FLAGS_PRINT)
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| 74 | *p++ = 'p';
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| 75 | if (p == buf)
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| 76 | *p++ = '-';
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| 77 | *p = '\0';
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| 78 |
|
| 79 | return buf;
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| 80 | }
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| 81 |
|
| 82 | |
| 83 | * Search the tables for _ddebug's which match the given
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| 84 | * `query' and apply the `flags' and `mask' to them. Tells
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| 85 | * the user which ddebug's were changed, or whether none
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| 86 | * were matched.
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| 87 |
|
| 88 | static void ddebug_change(const struct ddebug_query *query,
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| 89 | unsigned int flags, unsigned int mask)
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| 90 | {
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| 91 | int i;
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| 92 | struct ddebug_table *dt;
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| 93 | unsigned int newflags;
|
| 94 | unsigned int nfound = 0;
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| 95 | char flagbuf[8];
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| 96 |
|
| 97 |
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| 98 | mutex_lock(&ddebug_lock);
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| 99 | list_for_each_entry(dt, &ddebug_tables, link) {
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| 100 |
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| 101 |
|
| 102 | if (query->module != NULL &&
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| 103 | strcmp(query->module, dt->mod_name))
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| 104 | continue;
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| 105 |
|
| 106 | for (i = 0 ; i < dt->num_ddebugs ; i++) {
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| 107 | struct _ddebug *dp = &dt->ddebugs[i];
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| 108 |
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| 109 |
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| 110 | if (query->filename != NULL &&
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| 111 | strcmp(query->filename, dp->filename) &&
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| 112 | strcmp(query->filename, basename(dp->filename)))
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| 113 | continue;
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| 114 |
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| 115 |
|
| 116 | if (query->function != NULL &&
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| 117 | strcmp(query->function, dp->function))
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| 118 | continue;
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| 119 |
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| 120 |
|
| 121 | if (query->format != NULL &&
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| 122 | strstr(dp->format, query->format) == NULL)
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| 123 | continue;
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| 124 |
|
| 125 |
|
| 126 | if (query->first_lineno &&
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| 127 | dp->lineno < query->first_lineno)
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| 128 | continue;
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| 129 | if (query->last_lineno &&
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| 130 | dp->lineno > query->last_lineno)
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| 131 | continue;
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| 132 |
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| 133 | nfound++;
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| 134 |
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| 135 | newflags = (dp->flags & mask) | flags;
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| 136 | if (newflags == dp->flags)
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| 137 | continue;
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| 138 |
|
| 139 | if (!newflags)
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| 140 | dt->num_enabled--;
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| 141 | else if (!dp->flags)
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| 142 | dt->num_enabled++;
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| 143 | dp->flags = newflags;
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| 144 | if (newflags) {
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| 145 | jump_label_enable(&dp->enabled);
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| 146 | } else {
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| 147 | jump_label_disable(&dp->enabled);
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| 148 | }
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| 149 | if (verbose)
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| 150 | printk(KERN_INFO
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| 151 | "ddebug: changed %s:%d [%s]%s %s\n",
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| 152 | dp->filename, dp->lineno,
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| 153 | dt->mod_name, dp->function,
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| 154 | ddebug_describe_flags(dp, flagbuf,
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| 155 | sizeof(flagbuf)));
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| 156 | }
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| 157 | }
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| 158 | mutex_unlock(&ddebug_lock);
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| 159 |
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| 160 | if (!nfound && verbose)
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| 161 | printk(KERN_INFO "ddebug: no matches for query\n");
|
| 162 | }
|
| 163 |
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| 164 | |
| 165 | * Split the buffer `buf' into space-separated words.
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| 166 | * Handles simple " and ' quoting, i.e. without nested,
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| 167 | * embedded or escaped \". Return the number of words
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| 168 | * or <0 on error.
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| 169 |
|
| 170 | static int ddebug_tokenize(char *buf, char *words[], int maxwords)
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| 171 | {
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| 172 | int nwords = 0;
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| 173 |
|
| 174 | while (*buf) {
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| 175 | char *end;
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| 176 |
|
| 177 |
|
| 178 | buf = skip_spaces(buf);
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| 179 | if (!*buf)
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| 180 | break;
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| 181 |
|
| 182 |
|
| 183 | if (*buf == '"' || *buf == '\'') {
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| 184 | int quote = *buf++;
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| 185 | for (end = buf ; *end && *end != quote ; end++)
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| 186 | ;
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| 187 | if (!*end)
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| 188 | return -EINVAL;
|
| 189 | } else {
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| 190 | for (end = buf ; *end && !isspace(*end) ; end++)
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| 191 | ;
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| 192 | BUG_ON(end == buf);
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| 193 | }
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| 194 |
|
| 195 |
|
| 196 | if (nwords == maxwords)
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| 197 | return -EINVAL;
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| 198 | if (*end)
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| 199 | *end++ = '\0';
|
| 200 | words[nwords++] = buf;
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| 201 | buf = end;
|
| 202 | }
|
| 203 |
|
| 204 | if (verbose) {
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| 205 | int i;
|
| 206 | printk(KERN_INFO "%s: split into words:", __func__);
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| 207 | for (i = 0 ; i < nwords ; i++)
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| 208 | printk(" \"%s\"", words[i]);
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| 209 | printk("\n");
|
| 210 | }
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| 211 |
|
| 212 | return nwords;
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| 213 | }
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| 214 |
|
| 215 | |
| 216 | * Parse a single line number. Note that the empty string ""
|
| 217 | * is treated as a special case and converted to zero, which
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| 218 | * is later treated as a "don't care" value.
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| 219 |
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| 220 | static inline int parse_lineno(const char *str, unsigned int *val)
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| 221 | {
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| 222 | char *end = NULL;
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| 223 | BUG_ON(str == NULL);
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| 224 | if (*str == '\0') {
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| 225 | *val = 0;
|
| 226 | return 0;
|
| 227 | }
|
| 228 | *val = simple_strtoul(str, &end, 10);
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| 229 | return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
|
| 230 | }
|
| 231 |
|
| 232 | |
| 233 | * Undo octal escaping in a string, inplace. This is useful to
|
| 234 | * allow the user to express a query which matches a format
|
| 235 | * containing embedded spaces.
|
| 236 |
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| 237 | #define isodigit(c) ((c) >= '0' && (c) <= '7')
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| 238 | static char *unescape(char *str)
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| 239 | {
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| 240 | char *in = str;
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| 241 | char *out = str;
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| 242 |
|
| 243 | while (*in) {
|
| 244 | if (*in == '\\') {
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| 245 | if (in[1] == '\\') {
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| 246 | *out++ = '\\';
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| 247 | in += 2;
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| 248 | continue;
|
| 249 | } else if (in[1] == 't') {
|
| 250 | *out++ = '\t';
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| 251 | in += 2;
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| 252 | continue;
|
| 253 | } else if (in[1] == 'n') {
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| 254 | *out++ = '\n';
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| 255 | in += 2;
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| 256 | continue;
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| 257 | } else if (isodigit(in[1]) &&
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| 258 | isodigit(in[2]) &&
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| 259 | isodigit(in[3])) {
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| 260 | *out++ = ((in[1] - '0')<<6) |
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| 261 | ((in[2] - '0')<<3) |
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| 262 | (in[3] - '0');
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| 263 | in += 4;
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| 264 | continue;
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| 265 | }
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| 266 | }
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| 267 | *out++ = *in++;
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| 268 | }
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| 269 | *out = '\0';
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| 270 |
|
| 271 | return str;
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| 272 | }
|
| 273 |
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| 274 | |
| 275 | * Parse words[] as a ddebug query specification, which is a series
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| 276 | * of (keyword, value) pairs chosen from these possibilities:
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| 277 | *
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| 278 | * func <function-name>
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| 279 | * file <full-pathname>
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| 280 | * file <base-filename>
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| 281 | * module <module-name>
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| 282 | * format <escaped-string-to-find-in-format>
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| 283 | * line <lineno>
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| 284 | * line <first-lineno>-<last-lineno> // where either may be empty
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| 285 |
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| 286 | static int ddebug_parse_query(char *words[], int nwords,
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| 287 | struct ddebug_query *query)
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| 288 | {
|
| 289 | unsigned int i;
|
| 290 |
|
| 291 |
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| 292 | if (nwords % 2 != 0)
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| 293 | return -EINVAL;
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| 294 | memset(query, 0, sizeof(*query));
|
| 295 |
|
| 296 | for (i = 0 ; i < nwords ; i += 2) {
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| 297 | if (!strcmp(words[i], "func"))
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| 298 | query->function = words[i+1];
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| 299 | else if (!strcmp(words[i], "file"))
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| 300 | query->filename = words[i+1];
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| 301 | else if (!strcmp(words[i], "module"))
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| 302 | query->module = words[i+1];
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| 303 | else if (!strcmp(words[i], "format"))
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| 304 | query->format = unescape(words[i+1]);
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| 305 | else if (!strcmp(words[i], "line")) {
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| 306 | char *first = words[i+1];
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| 307 | char *last = strchr(first, '-');
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| 308 | if (last)
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| 309 | *last++ = '\0';
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| 310 | if (parse_lineno(first, &query->first_lineno) < 0)
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| 311 | return -EINVAL;
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| 312 | if (last != NULL) {
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| 313 |
|
| 314 | if (parse_lineno(last, &query->last_lineno) < 0)
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| 315 | return -EINVAL;
|
| 316 | } else {
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| 317 | query->last_lineno = query->first_lineno;
|
| 318 | }
|
| 319 | } else {
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| 320 | if (verbose)
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| 321 | printk(KERN_ERR "%s: unknown keyword \"%s\"\n",
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| 322 | __func__, words[i]);
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| 323 | return -EINVAL;
|
| 324 | }
|
| 325 | }
|
| 326 |
|
| 327 | if (verbose)
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| 328 | printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" "
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| 329 | "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
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| 330 | __func__, query->function, query->filename,
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| 331 | query->module, query->format, query->first_lineno,
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| 332 | query->last_lineno);
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| 333 |
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| 334 | return 0;
|
| 335 | }
|
| 336 |
|
| 337 | |
| 338 | * Parse `str' as a flags specification, format [-+=][p]+.
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| 339 | * Sets up *maskp and *flagsp to be used when changing the
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| 340 | * flags fields of matched _ddebug's. Returns 0 on success
|
| 341 | * or <0 on error.
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| 342 |
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| 343 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
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| 344 | unsigned int *maskp)
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| 345 | {
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| 346 | unsigned flags = 0;
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| 347 | int op = '=';
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| 348 |
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| 349 | switch (*str) {
|
| 350 | case '+':
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| 351 | case '-':
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| 352 | case '=':
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| 353 | op = *str++;
|
| 354 | break;
|
| 355 | default:
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| 356 | return -EINVAL;
|
| 357 | }
|
| 358 | if (verbose)
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| 359 | printk(KERN_INFO "%s: op='%c'\n", __func__, op);
|
| 360 |
|
| 361 | for ( ; *str ; ++str) {
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| 362 | switch (*str) {
|
| 363 | case 'p':
|
| 364 | flags |= _DPRINTK_FLAGS_PRINT;
|
| 365 | break;
|
| 366 | default:
|
| 367 | return -EINVAL;
|
| 368 | }
|
| 369 | }
|
| 370 | if (flags == 0)
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| 371 | return -EINVAL;
|
| 372 | if (verbose)
|
| 373 | printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags);
|
| 374 |
|
| 375 |
|
| 376 | switch (op) {
|
| 377 | case '=':
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| 378 | *maskp = 0;
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| 379 | *flagsp = flags;
|
| 380 | break;
|
| 381 | case '+':
|
| 382 | *maskp = ~0U;
|
| 383 | *flagsp = flags;
|
| 384 | break;
|
| 385 | case '-':
|
| 386 | *maskp = ~flags;
|
| 387 | *flagsp = 0;
|
| 388 | break;
|
| 389 | }
|
| 390 | if (verbose)
|
| 391 | printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n",
|
| 392 | __func__, *flagsp, *maskp);
|
| 393 | return 0;
|
| 394 | }
|
| 395 |
|
| 396 | static int ddebug_exec_query(char *query_string)
|
| 397 | {
|
| 398 | unsigned int flags = 0, mask = 0;
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| 399 | struct ddebug_query query;
|
| 400 | #define MAXWORDS 9
|
| 401 | int nwords;
|
| 402 | char *words[MAXWORDS];
|
| 403 |
|
| 404 | nwords = ddebug_tokenize(query_string, words, MAXWORDS);
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| 405 | if (nwords <= 0)
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| 406 | return -EINVAL;
|
| 407 | if (ddebug_parse_query(words, nwords-1, &query))
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| 408 | return -EINVAL;
|
| 409 | if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
|
| 410 | return -EINVAL;
|
| 411 |
|
| 412 |
|
| 413 | ddebug_change(&query, flags, mask);
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| 414 | return 0;
|
| 415 | }
|
| 416 |
|
| 417 | static __initdata char ddebug_setup_string[1024];
|
| 418 | static __init int ddebug_setup_query(char *str)
|
| 419 | {
|
| 420 | if (strlen(str) >= 1024) {
|
| 421 | pr_warning("ddebug boot param string too large\n");
|
| 422 | return 0;
|
| 423 | }
|
| 424 | strcpy(ddebug_setup_string, str);
|
| 425 | return 1;
|
| 426 | }
|
| 427 |
|
| 428 | __setup("ddebug_query=", ddebug_setup_query);
|
| 429 |
|
| 430 | |
| 431 | * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
|
| 432 | * command text from userspace, parses and executes it.
|
| 433 |
|
| 434 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
|
| 435 | size_t len, loff_t *offp)
|
| 436 | {
|
| 437 | char tmpbuf[256];
|
| 438 | int ret;
|
| 439 |
|
| 440 | if (len == 0)
|
| 441 | return 0;
|
| 442 |
|
| 443 | if (len > sizeof(tmpbuf)-1)
|
| 444 | return -E2BIG;
|
| 445 | if (copy_from_user(tmpbuf, ubuf, len))
|
| 446 | return -EFAULT;
|
| 447 | tmpbuf[len] = '\0';
|
| 448 | if (verbose)
|
| 449 | printk(KERN_INFO "%s: read %d bytes from userspace\n",
|
| 450 | __func__, (int)len);
|
| 451 |
|
| 452 | ret = ddebug_exec_query(tmpbuf);
|
| 453 | if (ret)
|
| 454 | return ret;
|
| 455 |
|
| 456 | *offp += len;
|
| 457 | return len;
|
| 458 | }
|
| 459 |
|
| 460 | |
| 461 | * Set the iterator to point to the first _ddebug object
|
| 462 | * and return a pointer to that first object. Returns
|
| 463 | * NULL if there are no _ddebugs at all.
|
| 464 |
|
| 465 | static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
|
| 466 | {
|
| 467 | if (list_empty(&ddebug_tables)) {
|
| 468 | iter->table = NULL;
|
| 469 | iter->idx = 0;
|
| 470 | return NULL;
|
| 471 | }
|
| 472 | iter->table = list_entry(ddebug_tables.next,
|
| 473 | struct ddebug_table, link);
|
| 474 | iter->idx = 0;
|
| 475 | return &iter->table->ddebugs[iter->idx];
|
| 476 | }
|
| 477 |
|
| 478 | |
| 479 | * Advance the iterator to point to the next _ddebug
|
| 480 | * object from the one the iterator currently points at,
|
| 481 | * and returns a pointer to the new _ddebug. Returns
|
| 482 | * NULL if the iterator has seen all the _ddebugs.
|
| 483 |
|
| 484 | static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
|
| 485 | {
|
| 486 | if (iter->table == NULL)
|
| 487 | return NULL;
|
| 488 | if (++iter->idx == iter->table->num_ddebugs) {
|
| 489 |
|
| 490 | iter->idx = 0;
|
| 491 | if (list_is_last(&iter->table->link, &ddebug_tables)) {
|
| 492 | iter->table = NULL;
|
| 493 | return NULL;
|
| 494 | }
|
| 495 | iter->table = list_entry(iter->table->link.next,
|
| 496 | struct ddebug_table, link);
|
| 497 | }
|
| 498 | return &iter->table->ddebugs[iter->idx];
|
| 499 | }
|
| 500 |
|
| 501 | |
| 502 | * Seq_ops start method. Called at the start of every
|
| 503 | * read() call from userspace. Takes the ddebug_lock and
|
| 504 | * seeks the seq_file's iterator to the given position.
|
| 505 |
|
| 506 | static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
|
| 507 | {
|
| 508 | struct ddebug_iter *iter = m->private;
|
| 509 | struct _ddebug *dp;
|
| 510 | int n = *pos;
|
| 511 |
|
| 512 | if (verbose)
|
| 513 | printk(KERN_INFO "%s: called m=%p *pos=%lld\n",
|
| 514 | __func__, m, (unsigned long long)*pos);
|
| 515 |
|
| 516 | mutex_lock(&ddebug_lock);
|
| 517 |
|
| 518 | if (!n)
|
| 519 | return SEQ_START_TOKEN;
|
| 520 | if (n < 0)
|
| 521 | return NULL;
|
| 522 | dp = ddebug_iter_first(iter);
|
| 523 | while (dp != NULL && --n > 0)
|
| 524 | dp = ddebug_iter_next(iter);
|
| 525 | return dp;
|
| 526 | }
|
| 527 |
|
| 528 | |
| 529 | * Seq_ops next method. Called several times within a read()
|
| 530 | * call from userspace, with ddebug_lock held. Walks to the
|
| 531 | * next _ddebug object with a special case for the header line.
|
| 532 |
|
| 533 | static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
|
| 534 | {
|
| 535 | struct ddebug_iter *iter = m->private;
|
| 536 | struct _ddebug *dp;
|
| 537 |
|
| 538 | if (verbose)
|
| 539 | printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n",
|
| 540 | __func__, m, p, (unsigned long long)*pos);
|
| 541 |
|
| 542 | if (p == SEQ_START_TOKEN)
|
| 543 | dp = ddebug_iter_first(iter);
|
| 544 | else
|
| 545 | dp = ddebug_iter_next(iter);
|
| 546 | ++*pos;
|
| 547 | return dp;
|
| 548 | }
|
| 549 |
|
| 550 | |
| 551 | * Seq_ops show method. Called several times within a read()
|
| 552 | * call from userspace, with ddebug_lock held. Formats the
|
| 553 | * current _ddebug as a single human-readable line, with a
|
| 554 | * special case for the header line.
|
| 555 |
|
| 556 | static int ddebug_proc_show(struct seq_file *m, void *p)
|
| 557 | {
|
| 558 | struct ddebug_iter *iter = m->private;
|
| 559 | struct _ddebug *dp = p;
|
| 560 | char flagsbuf[8];
|
| 561 |
|
| 562 | if (verbose)
|
| 563 | printk(KERN_INFO "%s: called m=%p p=%p\n",
|
| 564 | __func__, m, p);
|
| 565 |
|
| 566 | if (p == SEQ_START_TOKEN) {
|
| 567 | seq_puts(m,
|
| 568 | "# filename:lineno [module]function flags format\n");
|
| 569 | return 0;
|
| 570 | }
|
| 571 |
|
| 572 | seq_printf(m, "%s:%u [%s]%s %s \"",
|
| 573 | dp->filename, dp->lineno,
|
| 574 | iter->table->mod_name, dp->function,
|
| 575 | ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
|
| 576 | seq_escape(m, dp->format, "\t\r\n\"");
|
| 577 | seq_puts(m, "\"\n");
|
| 578 |
|
| 579 | return 0;
|
| 580 | }
|
| 581 |
|
| 582 | |
| 583 | * Seq_ops stop method. Called at the end of each read()
|
| 584 | * call from userspace. Drops ddebug_lock.
|
| 585 |
|
| 586 | static void ddebug_proc_stop(struct seq_file *m, void *p)
|
| 587 | {
|
| 588 | if (verbose)
|
| 589 | printk(KERN_INFO "%s: called m=%p p=%p\n",
|
| 590 | __func__, m, p);
|
| 591 | mutex_unlock(&ddebug_lock);
|
| 592 | }
|
| 593 |
|
| 594 | static const struct seq_operations ddebug_proc_seqops = {
|
| 595 | .start = ddebug_proc_start,
|
| 596 | .next = ddebug_proc_next,
|
| 597 | .show = ddebug_proc_show,
|
| 598 | .stop = ddebug_proc_stop
|
| 599 | };
|
| 600 |
|
| 601 | |
| 602 | * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file
|
| 603 | * setup dance, and also creates an iterator to walk the _ddebugs.
|
| 604 | * Note that we create a seq_file always, even for O_WRONLY files
|
| 605 | * where it's not needed, as doing so simplifies the ->release method.
|
| 606 |
|
| 607 | static int ddebug_proc_open(struct inode *inode, struct file *file)
|
| 608 | {
|
| 609 | struct ddebug_iter *iter;
|
| 610 | int err;
|
| 611 |
|
| 612 | if (verbose)
|
| 613 | printk(KERN_INFO "%s: called\n", __func__);
|
| 614 |
|
| 615 | iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
| 616 | if (iter == NULL)
|
| 617 | return -ENOMEM;
|
| 618 |
|
| 619 | err = seq_open(file, &ddebug_proc_seqops);
|
| 620 | if (err) {
|
| 621 | kfree(iter);
|
| 622 | return err;
|
| 623 | }
|
| 624 | ((struct seq_file *) file->private_data)->private = iter;
|
| 625 | return 0;
|
| 626 | }
|
| 627 |
|
| 628 | static const struct file_operations ddebug_proc_fops = {
|
| 629 | .owner = THIS_MODULE,
|
| 630 | .open = ddebug_proc_open,
|
| 631 | .read = seq_read,
|
| 632 | .llseek = seq_lseek,
|
| 633 | .release = seq_release_private,
|
| 634 | .write = ddebug_proc_write
|
| 635 | };
|
| 636 |
|
| 637 | |
| 638 | * Allocate a new ddebug_table for the given module
|
| 639 | * and add it to the global list.
|
| 640 |
|
| 641 | int ddebug_add_module(struct _ddebug *tab, unsigned int n,
|
| 642 | const char *name)
|
| 643 | {
|
| 644 | struct ddebug_table *dt;
|
| 645 | char *new_name;
|
| 646 |
|
| 647 | dt = kzalloc(sizeof(*dt), GFP_KERNEL);
|
| 648 | if (dt == NULL)
|
| 649 | return -ENOMEM;
|
| 650 | new_name = kstrdup(name, GFP_KERNEL);
|
| 651 | if (new_name == NULL) {
|
| 652 | kfree(dt);
|
| 653 | return -ENOMEM;
|
| 654 | }
|
| 655 | dt->mod_name = new_name;
|
| 656 | dt->num_ddebugs = n;
|
| 657 | dt->num_enabled = 0;
|
| 658 | dt->ddebugs = tab;
|
| 659 |
|
| 660 | mutex_lock(&ddebug_lock);
|
| 661 | list_add_tail(&dt->link, &ddebug_tables);
|
| 662 | mutex_unlock(&ddebug_lock);
|
| 663 |
|
| 664 | if (verbose)
|
| 665 | printk(KERN_INFO "%u debug prints in module %s\n",
|
| 666 | n, dt->mod_name);
|
| 667 | return 0;
|
| 668 | }
|
| 669 | EXPORT_SYMBOL_GPL(ddebug_add_module);
|
| 670 |
|
| 671 | static void ddebug_table_free(struct ddebug_table *dt)
|
| 672 | {
|
| 673 | list_del_init(&dt->link);
|
| 674 | kfree(dt->mod_name);
|
| 675 | kfree(dt);
|
| 676 | }
|
| 677 |
|
| 678 | |
| 679 | * Called in response to a module being unloaded. Removes
|
| 680 | * any ddebug_table's which point at the module.
|
| 681 |
|
| 682 | int ddebug_remove_module(const char *mod_name)
|
| 683 | {
|
| 684 | struct ddebug_table *dt, *nextdt;
|
| 685 | int ret = -ENOENT;
|
| 686 |
|
| 687 | if (verbose)
|
| 688 | printk(KERN_INFO "%s: removing module \"%s\"\n",
|
| 689 | __func__, mod_name);
|
| 690 |
|
| 691 | mutex_lock(&ddebug_lock);
|
| 692 | list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
|
| 693 | if (!strcmp(dt->mod_name, mod_name)) {
|
| 694 | ddebug_table_free(dt);
|
| 695 | ret = 0;
|
| 696 | }
|
| 697 | }
|
| 698 | mutex_unlock(&ddebug_lock);
|
| 699 | return ret;
|
| 700 | }
|
| 701 | EXPORT_SYMBOL_GPL(ddebug_remove_module);
|
| 702 |
|
| 703 | static void ddebug_remove_all_tables(void)
|
| 704 | {
|
| 705 | mutex_lock(&ddebug_lock);
|
| 706 | while (!list_empty(&ddebug_tables)) {
|
| 707 | struct ddebug_table *dt = list_entry(ddebug_tables.next,
|
| 708 | struct ddebug_table,
|
| 709 | link);
|
| 710 | ddebug_table_free(dt);
|
| 711 | }
|
| 712 | mutex_unlock(&ddebug_lock);
|
| 713 | }
|
| 714 |
|
| 715 | static __initdata int ddebug_init_success;
|
| 716 |
|
| 717 | static int __init dynamic_debug_init_debugfs(void)
|
| 718 | {
|
| 719 | struct dentry *dir, *file;
|
| 720 |
|
| 721 | if (!ddebug_init_success)
|
| 722 | return -ENODEV;
|
| 723 |
|
| 724 | dir = debugfs_create_dir("dynamic_debug", NULL);
|
| 725 | if (!dir)
|
| 726 | return -ENOMEM;
|
| 727 | file = debugfs_create_file("control", 0644, dir, NULL,
|
| 728 | &ddebug_proc_fops);
|
| 729 | if (!file) {
|
| 730 | debugfs_remove(dir);
|
| 731 | return -ENOMEM;
|
| 732 | }
|
| 733 | return 0;
|
| 734 | }
|
| 735 |
|
| 736 | static int __init dynamic_debug_init(void)
|
| 737 | {
|
| 738 | struct _ddebug *iter, *iter_start;
|
| 739 | const char *modname = NULL;
|
| 740 | int ret = 0;
|
| 741 | int n = 0;
|
| 742 |
|
| 743 | if (__start___verbose != __stop___verbose) {
|
| 744 | iter = __start___verbose;
|
| 745 | modname = iter->modname;
|
| 746 | iter_start = iter;
|
| 747 | for (; iter < __stop___verbose; iter++) {
|
| 748 | if (strcmp(modname, iter->modname)) {
|
| 749 | ret = ddebug_add_module(iter_start, n, modname);
|
| 750 | if (ret)
|
| 751 | goto out_free;
|
| 752 | n = 0;
|
| 753 | modname = iter->modname;
|
| 754 | iter_start = iter;
|
| 755 | }
|
| 756 | n++;
|
| 757 | }
|
| 758 | ret = ddebug_add_module(iter_start, n, modname);
|
| 759 | }
|
| 760 |
|
| 761 |
|
| 762 | if (ddebug_setup_string[0] != '\0') {
|
| 763 | ret = ddebug_exec_query(ddebug_setup_string);
|
| 764 | if (ret)
|
| 765 | pr_warning("Invalid ddebug boot param %s",
|
| 766 | ddebug_setup_string);
|
| 767 | else
|
| 768 | pr_info("ddebug initialized with string %s",
|
| 769 | ddebug_setup_string);
|
| 770 | }
|
| 771 |
|
| 772 | out_free:
|
| 773 | if (ret)
|
| 774 | ddebug_remove_all_tables();
|
| 775 | else
|
| 776 | ddebug_init_success = 1;
|
| 777 | return 0;
|
| 778 | }
|
| 779 |
|
| 780 | arch_initcall(dynamic_debug_init);
|
| 781 |
|
| 782 | module_init(dynamic_debug_init_debugfs);
|