| 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 | * Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
|
| 11 |
|
| 12 |
|
| 13 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
|
| 14 |
|
| 15 | #include <linux/kernel.h>
|
| 16 | #include <linux/module.h>
|
| 17 | #include <linux/moduleparam.h>
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| 18 | #include <linux/kallsyms.h>
|
| 19 | #include <linux/types.h>
|
| 20 | #include <linux/mutex.h>
|
| 21 | #include <linux/proc_fs.h>
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| 22 | #include <linux/seq_file.h>
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| 23 | #include <linux/list.h>
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| 24 | #include <linux/sysctl.h>
|
| 25 | #include <linux/ctype.h>
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| 26 | #include <linux/string.h>
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| 27 | #include <linux/uaccess.h>
|
| 28 | #include <linux/dynamic_debug.h>
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| 29 | #include <linux/debugfs.h>
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| 30 | #include <linux/slab.h>
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| 31 | #include <linux/jump_label.h>
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| 32 | #include <linux/hardirq.h>
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| 33 | #include <linux/sched.h>
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| 34 | #include <linux/device.h>
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| 35 | #include <linux/netdevice.h>
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| 36 |
|
| 37 | extern struct _ddebug __start___verbose[];
|
| 38 | extern struct _ddebug __stop___verbose[];
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| 39 |
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| 40 | struct ddebug_table {
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| 41 | struct list_head link;
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| 42 | char *mod_name;
|
| 43 | unsigned int num_ddebugs;
|
| 44 | struct _ddebug *ddebugs;
|
| 45 | };
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| 46 |
|
| 47 | struct ddebug_query {
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| 48 | const char *filename;
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| 49 | const char *module;
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| 50 | const char *function;
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| 51 | const char *format;
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| 52 | unsigned int first_lineno, last_lineno;
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| 53 | };
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| 54 |
|
| 55 | struct ddebug_iter {
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| 56 | struct ddebug_table *table;
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| 57 | unsigned int idx;
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| 58 | };
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| 59 |
|
| 60 | static DEFINE_MUTEX(ddebug_lock);
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| 61 | static LIST_HEAD(ddebug_tables);
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| 62 | static int verbose;
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| 63 | module_param(verbose, int, 0644);
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| 64 |
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| 65 |
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| 66 | static inline const char *trim_prefix(const char *path)
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| 67 | {
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| 68 | int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
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| 69 |
|
| 70 | if (strncmp(path, __FILE__, skip))
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| 71 | skip = 0;
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| 72 |
|
| 73 | return path + skip;
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| 74 | }
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| 75 |
|
| 76 | static struct { unsigned flag:8; char opt_char; } opt_array[] = {
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| 77 | { _DPRINTK_FLAGS_PRINT, 'p' },
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| 78 | { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
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| 79 | { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
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| 80 | { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
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| 81 | { _DPRINTK_FLAGS_INCL_TID, 't' },
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| 82 | { _DPRINTK_FLAGS_NONE, '_' },
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| 83 | };
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| 84 |
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| 85 |
|
| 86 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
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| 87 | size_t maxlen)
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| 88 | {
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| 89 | char *p = buf;
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| 90 | int i;
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| 91 |
|
| 92 | BUG_ON(maxlen < 6);
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| 93 | for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
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| 94 | if (dp->flags & opt_array[i].flag)
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| 95 | *p++ = opt_array[i].opt_char;
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| 96 | if (p == buf)
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| 97 | *p++ = '_';
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| 98 | *p = '\0';
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| 99 |
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| 100 | return buf;
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| 101 | }
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| 102 |
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| 103 | #define vpr_info(fmt, ...) \
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| 104 | do { \
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| 105 | if (verbose) \
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| 106 | pr_info(fmt, ##__VA_ARGS__); \
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| 107 | } while (0)
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| 108 |
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| 109 | static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
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| 110 | {
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| 111 |
|
| 112 | int fmtlen = 0;
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| 113 |
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| 114 | if (query->format) {
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| 115 | fmtlen = strlen(query->format);
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| 116 | while (fmtlen && query->format[fmtlen - 1] == '\n')
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| 117 | fmtlen--;
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| 118 | }
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| 119 |
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| 120 | vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
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| 121 | msg,
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| 122 | query->function ? query->function : "",
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| 123 | query->filename ? query->filename : "",
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| 124 | query->module ? query->module : "",
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| 125 | fmtlen, query->format ? query->format : "",
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| 126 | query->first_lineno, query->last_lineno);
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| 127 | }
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| 128 |
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| 129 | |
| 130 | * Search the tables for _ddebug's which match the given `query' and
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| 131 | * apply the `flags' and `mask' to them. Returns number of matching
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| 132 | * callsites, normally the same as number of changes. If verbose,
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| 133 | * logs the changes. Takes ddebug_lock.
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| 134 |
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| 135 | static int ddebug_change(const struct ddebug_query *query,
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| 136 | unsigned int flags, unsigned int mask)
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| 137 | {
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| 138 | int i;
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| 139 | struct ddebug_table *dt;
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| 140 | unsigned int newflags;
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| 141 | unsigned int nfound = 0;
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| 142 | char flagbuf[10];
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| 143 |
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| 144 |
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| 145 | mutex_lock(&ddebug_lock);
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| 146 | list_for_each_entry(dt, &ddebug_tables, link) {
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| 147 |
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| 148 |
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| 149 | if (query->module && strcmp(query->module, dt->mod_name))
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| 150 | continue;
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| 151 |
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| 152 | for (i = 0; i < dt->num_ddebugs; i++) {
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| 153 | struct _ddebug *dp = &dt->ddebugs[i];
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| 154 |
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| 155 |
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| 156 | if (query->filename &&
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| 157 | strcmp(query->filename, dp->filename) &&
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| 158 | strcmp(query->filename, kbasename(dp->filename)) &&
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| 159 | strcmp(query->filename, trim_prefix(dp->filename)))
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| 160 | continue;
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| 161 |
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| 162 |
|
| 163 | if (query->function &&
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| 164 | strcmp(query->function, dp->function))
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| 165 | continue;
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| 166 |
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| 167 |
|
| 168 | if (query->format &&
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| 169 | !strstr(dp->format, query->format))
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| 170 | continue;
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| 171 |
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| 172 |
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| 173 | if (query->first_lineno &&
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| 174 | dp->lineno < query->first_lineno)
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| 175 | continue;
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| 176 | if (query->last_lineno &&
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| 177 | dp->lineno > query->last_lineno)
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| 178 | continue;
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| 179 |
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| 180 | nfound++;
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| 181 |
|
| 182 | newflags = (dp->flags & mask) | flags;
|
| 183 | if (newflags == dp->flags)
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| 184 | continue;
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| 185 | dp->flags = newflags;
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| 186 | vpr_info("changed %s:%d [%s]%s =%s\n",
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| 187 | trim_prefix(dp->filename), dp->lineno,
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| 188 | dt->mod_name, dp->function,
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| 189 | ddebug_describe_flags(dp, flagbuf,
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| 190 | sizeof(flagbuf)));
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| 191 | }
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| 192 | }
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| 193 | mutex_unlock(&ddebug_lock);
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| 194 |
|
| 195 | if (!nfound && verbose)
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| 196 | pr_info("no matches for query\n");
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| 197 |
|
| 198 | return nfound;
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| 199 | }
|
| 200 |
|
| 201 | |
| 202 | * Split the buffer `buf' into space-separated words.
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| 203 | * Handles simple " and ' quoting, i.e. without nested,
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| 204 | * embedded or escaped \". Return the number of words
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| 205 | * or <0 on error.
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| 206 |
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| 207 | static int ddebug_tokenize(char *buf, char *words[], int maxwords)
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| 208 | {
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| 209 | int nwords = 0;
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| 210 |
|
| 211 | while (*buf) {
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| 212 | char *end;
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| 213 |
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| 214 |
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| 215 | buf = skip_spaces(buf);
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| 216 | if (!*buf)
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| 217 | break;
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| 218 | if (*buf == '#')
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| 219 | break;
|
| 220 |
|
| 221 |
|
| 222 | if (*buf == '"' || *buf == '\'') {
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| 223 | int quote = *buf++;
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| 224 | for (end = buf; *end && *end != quote; end++)
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| 225 | ;
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| 226 | if (!*end) {
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| 227 | pr_err("unclosed quote: %s\n", buf);
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| 228 | return -EINVAL;
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| 229 | }
|
| 230 | } else {
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| 231 | for (end = buf; *end && !isspace(*end); end++)
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| 232 | ;
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| 233 | BUG_ON(end == buf);
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| 234 | }
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| 235 |
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| 236 |
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| 237 | if (nwords == maxwords) {
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| 238 | pr_err("too many words, legal max <=%d\n", maxwords);
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| 239 | return -EINVAL;
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| 240 | }
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| 241 | if (*end)
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| 242 | *end++ = '\0';
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| 243 | words[nwords++] = buf;
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| 244 | buf = end;
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| 245 | }
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| 246 |
|
| 247 | if (verbose) {
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| 248 | int i;
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| 249 | pr_info("split into words:");
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| 250 | for (i = 0; i < nwords; i++)
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| 251 | pr_cont(" \"%s\"", words[i]);
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| 252 | pr_cont("\n");
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| 253 | }
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| 254 |
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| 255 | return nwords;
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| 256 | }
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| 257 |
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| 258 | |
| 259 | * Parse a single line number. Note that the empty string ""
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| 260 | * is treated as a special case and converted to zero, which
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| 261 | * is later treated as a "don't care" value.
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| 262 |
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| 263 | static inline int parse_lineno(const char *str, unsigned int *val)
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| 264 | {
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| 265 | char *end = NULL;
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| 266 | BUG_ON(str == NULL);
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| 267 | if (*str == '\0') {
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| 268 | *val = 0;
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| 269 | return 0;
|
| 270 | }
|
| 271 | *val = simple_strtoul(str, &end, 10);
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| 272 | if (end == NULL || end == str || *end != '\0') {
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| 273 | pr_err("bad line-number: %s\n", str);
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| 274 | return -EINVAL;
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| 275 | }
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| 276 | return 0;
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| 277 | }
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| 278 |
|
| 279 | |
| 280 | * Undo octal escaping in a string, inplace. This is useful to
|
| 281 | * allow the user to express a query which matches a format
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| 282 | * containing embedded spaces.
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| 283 |
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| 284 | #define isodigit(c) ((c) >= '0' && (c) <= '7')
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| 285 | static char *unescape(char *str)
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| 286 | {
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| 287 | char *in = str;
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| 288 | char *out = str;
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| 289 |
|
| 290 | while (*in) {
|
| 291 | if (*in == '\\') {
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| 292 | if (in[1] == '\\') {
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| 293 | *out++ = '\\';
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| 294 | in += 2;
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| 295 | continue;
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| 296 | } else if (in[1] == 't') {
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| 297 | *out++ = '\t';
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| 298 | in += 2;
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| 299 | continue;
|
| 300 | } else if (in[1] == 'n') {
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| 301 | *out++ = '\n';
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| 302 | in += 2;
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| 303 | continue;
|
| 304 | } else if (isodigit(in[1]) &&
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| 305 | isodigit(in[2]) &&
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| 306 | isodigit(in[3])) {
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| 307 | *out++ = (((in[1] - '0') << 6) |
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| 308 | ((in[2] - '0') << 3) |
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| 309 | (in[3] - '0'));
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| 310 | in += 4;
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| 311 | continue;
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| 312 | }
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| 313 | }
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| 314 | *out++ = *in++;
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| 315 | }
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| 316 | *out = '\0';
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| 317 |
|
| 318 | return str;
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| 319 | }
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| 320 |
|
| 321 | static int check_set(const char **dest, char *src, char *name)
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| 322 | {
|
| 323 | int rc = 0;
|
| 324 |
|
| 325 | if (*dest) {
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| 326 | rc = -EINVAL;
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| 327 | pr_err("match-spec:%s val:%s overridden by %s\n",
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| 328 | name, *dest, src);
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| 329 | }
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| 330 | *dest = src;
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| 331 | return rc;
|
| 332 | }
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| 333 |
|
| 334 | |
| 335 | * Parse words[] as a ddebug query specification, which is a series
|
| 336 | * of (keyword, value) pairs chosen from these possibilities:
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| 337 | *
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| 338 | * func <function-name>
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| 339 | * file <full-pathname>
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| 340 | * file <base-filename>
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| 341 | * module <module-name>
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| 342 | * format <escaped-string-to-find-in-format>
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| 343 | * line <lineno>
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| 344 | * line <first-lineno>-<last-lineno> // where either may be empty
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| 345 | *
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| 346 | * Only 1 of each type is allowed.
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| 347 | * Returns 0 on success, <0 on error.
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| 348 |
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| 349 | static int ddebug_parse_query(char *words[], int nwords,
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| 350 | struct ddebug_query *query, const char *modname)
|
| 351 | {
|
| 352 | unsigned int i;
|
| 353 | int rc;
|
| 354 |
|
| 355 |
|
| 356 | if (nwords % 2 != 0) {
|
| 357 | pr_err("expecting pairs of match-spec <value>\n");
|
| 358 | return -EINVAL;
|
| 359 | }
|
| 360 | memset(query, 0, sizeof(*query));
|
| 361 |
|
| 362 | if (modname)
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| 363 |
|
| 364 | query->module = modname;
|
| 365 |
|
| 366 | for (i = 0; i < nwords; i += 2) {
|
| 367 | if (!strcmp(words[i], "func")) {
|
| 368 | rc = check_set(&query->function, words[i+1], "func");
|
| 369 | } else if (!strcmp(words[i], "file")) {
|
| 370 | rc = check_set(&query->filename, words[i+1], "file");
|
| 371 | } else if (!strcmp(words[i], "module")) {
|
| 372 | rc = check_set(&query->module, words[i+1], "module");
|
| 373 | } else if (!strcmp(words[i], "format")) {
|
| 374 | rc = check_set(&query->format, unescape(words[i+1]),
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| 375 | "format");
|
| 376 | } else if (!strcmp(words[i], "line")) {
|
| 377 | char *first = words[i+1];
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| 378 | char *last = strchr(first, '-');
|
| 379 | if (query->first_lineno || query->last_lineno) {
|
| 380 | pr_err("match-spec: line used 2x\n");
|
| 381 | return -EINVAL;
|
| 382 | }
|
| 383 | if (last)
|
| 384 | *last++ = '\0';
|
| 385 | if (parse_lineno(first, &query->first_lineno) < 0) {
|
| 386 | pr_err("line-number is <0\n");
|
| 387 | return -EINVAL;
|
| 388 | }
|
| 389 | if (last) {
|
| 390 |
|
| 391 | if (parse_lineno(last, &query->last_lineno)
|
| 392 | < query->first_lineno) {
|
| 393 | pr_err("last-line:%d < 1st-line:%d\n",
|
| 394 | query->last_lineno,
|
| 395 | query->first_lineno);
|
| 396 | return -EINVAL;
|
| 397 | }
|
| 398 | } else {
|
| 399 | query->last_lineno = query->first_lineno;
|
| 400 | }
|
| 401 | } else {
|
| 402 | pr_err("unknown keyword \"%s\"\n", words[i]);
|
| 403 | return -EINVAL;
|
| 404 | }
|
| 405 | if (rc)
|
| 406 | return rc;
|
| 407 | }
|
| 408 | vpr_info_dq(query, "parsed");
|
| 409 | return 0;
|
| 410 | }
|
| 411 |
|
| 412 | |
| 413 | * Parse `str' as a flags specification, format [-+=][p]+.
|
| 414 | * Sets up *maskp and *flagsp to be used when changing the
|
| 415 | * flags fields of matched _ddebug's. Returns 0 on success
|
| 416 | * or <0 on error.
|
| 417 |
|
| 418 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
|
| 419 | unsigned int *maskp)
|
| 420 | {
|
| 421 | unsigned flags = 0;
|
| 422 | int op = '=', i;
|
| 423 |
|
| 424 | switch (*str) {
|
| 425 | case '+':
|
| 426 | case '-':
|
| 427 | case '=':
|
| 428 | op = *str++;
|
| 429 | break;
|
| 430 | default:
|
| 431 | pr_err("bad flag-op %c, at start of %s\n", *str, str);
|
| 432 | return -EINVAL;
|
| 433 | }
|
| 434 | vpr_info("op='%c'\n", op);
|
| 435 |
|
| 436 | for (; *str ; ++str) {
|
| 437 | for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
|
| 438 | if (*str == opt_array[i].opt_char) {
|
| 439 | flags |= opt_array[i].flag;
|
| 440 | break;
|
| 441 | }
|
| 442 | }
|
| 443 | if (i < 0) {
|
| 444 | pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
|
| 445 | return -EINVAL;
|
| 446 | }
|
| 447 | }
|
| 448 | vpr_info("flags=0x%x\n", flags);
|
| 449 |
|
| 450 |
|
| 451 | switch (op) {
|
| 452 | case '=':
|
| 453 | *maskp = 0;
|
| 454 | *flagsp = flags;
|
| 455 | break;
|
| 456 | case '+':
|
| 457 | *maskp = ~0U;
|
| 458 | *flagsp = flags;
|
| 459 | break;
|
| 460 | case '-':
|
| 461 | *maskp = ~flags;
|
| 462 | *flagsp = 0;
|
| 463 | break;
|
| 464 | }
|
| 465 | vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
|
| 466 | return 0;
|
| 467 | }
|
| 468 |
|
| 469 | static int ddebug_exec_query(char *query_string, const char *modname)
|
| 470 | {
|
| 471 | unsigned int flags = 0, mask = 0;
|
| 472 | struct ddebug_query query;
|
| 473 | #define MAXWORDS 9
|
| 474 | int nwords, nfound;
|
| 475 | char *words[MAXWORDS];
|
| 476 |
|
| 477 | nwords = ddebug_tokenize(query_string, words, MAXWORDS);
|
| 478 | if (nwords <= 0) {
|
| 479 | pr_err("tokenize failed\n");
|
| 480 | return -EINVAL;
|
| 481 | }
|
| 482 |
|
| 483 | if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
|
| 484 | pr_err("flags parse failed\n");
|
| 485 | return -EINVAL;
|
| 486 | }
|
| 487 | if (ddebug_parse_query(words, nwords-1, &query, modname)) {
|
| 488 | pr_err("query parse failed\n");
|
| 489 | return -EINVAL;
|
| 490 | }
|
| 491 |
|
| 492 | nfound = ddebug_change(&query, flags, mask);
|
| 493 | vpr_info_dq(&query, nfound ? "applied" : "no-match");
|
| 494 |
|
| 495 | return nfound;
|
| 496 | }
|
| 497 |
|
| 498 | |
| 499 | last error or number of matching callsites. Module name is either
|
| 500 | in param (for boot arg) or perhaps in query string.
|
| 501 |
|
| 502 | static int ddebug_exec_queries(char *query, const char *modname)
|
| 503 | {
|
| 504 | char *split;
|
| 505 | int i, errs = 0, exitcode = 0, rc, nfound = 0;
|
| 506 |
|
| 507 | for (i = 0; query; query = split) {
|
| 508 | split = strpbrk(query, ";\n");
|
| 509 | if (split)
|
| 510 | *split++ = '\0';
|
| 511 |
|
| 512 | query = skip_spaces(query);
|
| 513 | if (!query || !*query || *query == '#')
|
| 514 | continue;
|
| 515 |
|
| 516 | vpr_info("query %d: \"%s\"\n", i, query);
|
| 517 |
|
| 518 | rc = ddebug_exec_query(query, modname);
|
| 519 | if (rc < 0) {
|
| 520 | errs++;
|
| 521 | exitcode = rc;
|
| 522 | } else {
|
| 523 | nfound += rc;
|
| 524 | }
|
| 525 | i++;
|
| 526 | }
|
| 527 | vpr_info("processed %d queries, with %d matches, %d errs\n",
|
| 528 | i, nfound, errs);
|
| 529 |
|
| 530 | if (exitcode)
|
| 531 | return exitcode;
|
| 532 | return nfound;
|
| 533 | }
|
| 534 |
|
| 535 | #define PREFIX_SIZE 64
|
| 536 |
|
| 537 | static int remaining(int wrote)
|
| 538 | {
|
| 539 | if (PREFIX_SIZE - wrote > 0)
|
| 540 | return PREFIX_SIZE - wrote;
|
| 541 | return 0;
|
| 542 | }
|
| 543 |
|
| 544 | static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
|
| 545 | {
|
| 546 | int pos_after_tid;
|
| 547 | int pos = 0;
|
| 548 |
|
| 549 | *buf = '\0';
|
| 550 |
|
| 551 | if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
|
| 552 | if (in_interrupt())
|
| 553 | pos += snprintf(buf + pos, remaining(pos), "<intr> ");
|
| 554 | else
|
| 555 | pos += snprintf(buf + pos, remaining(pos), "[%d] ",
|
| 556 | task_pid_vnr(current));
|
| 557 | }
|
| 558 | pos_after_tid = pos;
|
| 559 | if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
|
| 560 | pos += snprintf(buf + pos, remaining(pos), "%s:",
|
| 561 | desc->modname);
|
| 562 | if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
|
| 563 | pos += snprintf(buf + pos, remaining(pos), "%s:",
|
| 564 | desc->function);
|
| 565 | if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
|
| 566 | pos += snprintf(buf + pos, remaining(pos), "%d:",
|
| 567 | desc->lineno);
|
| 568 | if (pos - pos_after_tid)
|
| 569 | pos += snprintf(buf + pos, remaining(pos), " ");
|
| 570 | if (pos >= PREFIX_SIZE)
|
| 571 | buf[PREFIX_SIZE - 1] = '\0';
|
| 572 |
|
| 573 | return buf;
|
| 574 | }
|
| 575 |
|
| 576 | int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
|
| 577 | {
|
| 578 | va_list args;
|
| 579 | int res;
|
| 580 | struct va_format vaf;
|
| 581 | char buf[PREFIX_SIZE];
|
| 582 |
|
| 583 | BUG_ON(!descriptor);
|
| 584 | BUG_ON(!fmt);
|
| 585 |
|
| 586 | va_start(args, fmt);
|
| 587 |
|
| 588 | vaf.fmt = fmt;
|
| 589 | vaf.va = &args;
|
| 590 |
|
| 591 | res = printk(KERN_DEBUG "%s%pV",
|
| 592 | dynamic_emit_prefix(descriptor, buf), &vaf);
|
| 593 |
|
| 594 | va_end(args);
|
| 595 |
|
| 596 | return res;
|
| 597 | }
|
| 598 | EXPORT_SYMBOL(__dynamic_pr_debug);
|
| 599 |
|
| 600 | int __dynamic_dev_dbg(struct _ddebug *descriptor,
|
| 601 | const struct device *dev, const char *fmt, ...)
|
| 602 | {
|
| 603 | struct va_format vaf;
|
| 604 | va_list args;
|
| 605 | int res;
|
| 606 |
|
| 607 | BUG_ON(!descriptor);
|
| 608 | BUG_ON(!fmt);
|
| 609 |
|
| 610 | va_start(args, fmt);
|
| 611 |
|
| 612 | vaf.fmt = fmt;
|
| 613 | vaf.va = &args;
|
| 614 |
|
| 615 | if (!dev) {
|
| 616 | res = printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
|
| 617 | } else {
|
| 618 | char buf[PREFIX_SIZE];
|
| 619 |
|
| 620 | res = dev_printk_emit(7, dev, "%s%s %s: %pV",
|
| 621 | dynamic_emit_prefix(descriptor, buf),
|
| 622 | dev_driver_string(dev), dev_name(dev),
|
| 623 | &vaf);
|
| 624 | }
|
| 625 |
|
| 626 | va_end(args);
|
| 627 |
|
| 628 | return res;
|
| 629 | }
|
| 630 | EXPORT_SYMBOL(__dynamic_dev_dbg);
|
| 631 |
|
| 632 | #ifdef CONFIG_NET
|
| 633 |
|
| 634 | int __dynamic_netdev_dbg(struct _ddebug *descriptor,
|
| 635 | const struct net_device *dev, const char *fmt, ...)
|
| 636 | {
|
| 637 | struct va_format vaf;
|
| 638 | va_list args;
|
| 639 | int res;
|
| 640 |
|
| 641 | BUG_ON(!descriptor);
|
| 642 | BUG_ON(!fmt);
|
| 643 |
|
| 644 | va_start(args, fmt);
|
| 645 |
|
| 646 | vaf.fmt = fmt;
|
| 647 | vaf.va = &args;
|
| 648 |
|
| 649 | if (dev && dev->dev.parent) {
|
| 650 | char buf[PREFIX_SIZE];
|
| 651 |
|
| 652 | res = dev_printk_emit(7, dev->dev.parent,
|
| 653 | "%s%s %s %s: %pV",
|
| 654 | dynamic_emit_prefix(descriptor, buf),
|
| 655 | dev_driver_string(dev->dev.parent),
|
| 656 | dev_name(dev->dev.parent),
|
| 657 | netdev_name(dev), &vaf);
|
| 658 | } else if (dev) {
|
| 659 | res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf);
|
| 660 | } else {
|
| 661 | res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
|
| 662 | }
|
| 663 |
|
| 664 | va_end(args);
|
| 665 |
|
| 666 | return res;
|
| 667 | }
|
| 668 | EXPORT_SYMBOL(__dynamic_netdev_dbg);
|
| 669 |
|
| 670 | #endif
|
| 671 |
|
| 672 | #define DDEBUG_STRING_SIZE 1024
|
| 673 | static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
|
| 674 |
|
| 675 | static __init int ddebug_setup_query(char *str)
|
| 676 | {
|
| 677 | if (strlen(str) >= DDEBUG_STRING_SIZE) {
|
| 678 | pr_warn("ddebug boot param string too large\n");
|
| 679 | return 0;
|
| 680 | }
|
| 681 | strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
|
| 682 | return 1;
|
| 683 | }
|
| 684 |
|
| 685 | __setup("ddebug_query=", ddebug_setup_query);
|
| 686 |
|
| 687 | |
| 688 | * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
|
| 689 | * command text from userspace, parses and executes it.
|
| 690 |
|
| 691 | #define USER_BUF_PAGE 4096
|
| 692 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
|
| 693 | size_t len, loff_t *offp)
|
| 694 | {
|
| 695 | char *tmpbuf;
|
| 696 | int ret;
|
| 697 |
|
| 698 | if (len == 0)
|
| 699 | return 0;
|
| 700 | if (len > USER_BUF_PAGE - 1) {
|
| 701 | pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
|
| 702 | return -E2BIG;
|
| 703 | }
|
| 704 | tmpbuf = kmalloc(len + 1, GFP_KERNEL);
|
| 705 | if (!tmpbuf)
|
| 706 | return -ENOMEM;
|
| 707 | if (copy_from_user(tmpbuf, ubuf, len)) {
|
| 708 | kfree(tmpbuf);
|
| 709 | return -EFAULT;
|
| 710 | }
|
| 711 | tmpbuf[len] = '\0';
|
| 712 | vpr_info("read %d bytes from userspace\n", (int)len);
|
| 713 |
|
| 714 | ret = ddebug_exec_queries(tmpbuf, NULL);
|
| 715 | kfree(tmpbuf);
|
| 716 | if (ret < 0)
|
| 717 | return ret;
|
| 718 |
|
| 719 | *offp += len;
|
| 720 | return len;
|
| 721 | }
|
| 722 |
|
| 723 | |
| 724 | * Set the iterator to point to the first _ddebug object
|
| 725 | * and return a pointer to that first object. Returns
|
| 726 | * NULL if there are no _ddebugs at all.
|
| 727 |
|
| 728 | static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
|
| 729 | {
|
| 730 | if (list_empty(&ddebug_tables)) {
|
| 731 | iter->table = NULL;
|
| 732 | iter->idx = 0;
|
| 733 | return NULL;
|
| 734 | }
|
| 735 | iter->table = list_entry(ddebug_tables.next,
|
| 736 | struct ddebug_table, link);
|
| 737 | iter->idx = 0;
|
| 738 | return &iter->table->ddebugs[iter->idx];
|
| 739 | }
|
| 740 |
|
| 741 | |
| 742 | * Advance the iterator to point to the next _ddebug
|
| 743 | * object from the one the iterator currently points at,
|
| 744 | * and returns a pointer to the new _ddebug. Returns
|
| 745 | * NULL if the iterator has seen all the _ddebugs.
|
| 746 |
|
| 747 | static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
|
| 748 | {
|
| 749 | if (iter->table == NULL)
|
| 750 | return NULL;
|
| 751 | if (++iter->idx == iter->table->num_ddebugs) {
|
| 752 |
|
| 753 | iter->idx = 0;
|
| 754 | if (list_is_last(&iter->table->link, &ddebug_tables)) {
|
| 755 | iter->table = NULL;
|
| 756 | return NULL;
|
| 757 | }
|
| 758 | iter->table = list_entry(iter->table->link.next,
|
| 759 | struct ddebug_table, link);
|
| 760 | }
|
| 761 | return &iter->table->ddebugs[iter->idx];
|
| 762 | }
|
| 763 |
|
| 764 | |
| 765 | * Seq_ops start method. Called at the start of every
|
| 766 | * read() call from userspace. Takes the ddebug_lock and
|
| 767 | * seeks the seq_file's iterator to the given position.
|
| 768 |
|
| 769 | static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
|
| 770 | {
|
| 771 | struct ddebug_iter *iter = m->private;
|
| 772 | struct _ddebug *dp;
|
| 773 | int n = *pos;
|
| 774 |
|
| 775 | vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
|
| 776 |
|
| 777 | mutex_lock(&ddebug_lock);
|
| 778 |
|
| 779 | if (!n)
|
| 780 | return SEQ_START_TOKEN;
|
| 781 | if (n < 0)
|
| 782 | return NULL;
|
| 783 | dp = ddebug_iter_first(iter);
|
| 784 | while (dp != NULL && --n > 0)
|
| 785 | dp = ddebug_iter_next(iter);
|
| 786 | return dp;
|
| 787 | }
|
| 788 |
|
| 789 | |
| 790 | * Seq_ops next method. Called several times within a read()
|
| 791 | * call from userspace, with ddebug_lock held. Walks to the
|
| 792 | * next _ddebug object with a special case for the header line.
|
| 793 |
|
| 794 | static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
|
| 795 | {
|
| 796 | struct ddebug_iter *iter = m->private;
|
| 797 | struct _ddebug *dp;
|
| 798 |
|
| 799 | vpr_info("called m=%p p=%p *pos=%lld\n",
|
| 800 | m, p, (unsigned long long)*pos);
|
| 801 |
|
| 802 | if (p == SEQ_START_TOKEN)
|
| 803 | dp = ddebug_iter_first(iter);
|
| 804 | else
|
| 805 | dp = ddebug_iter_next(iter);
|
| 806 | ++*pos;
|
| 807 | return dp;
|
| 808 | }
|
| 809 |
|
| 810 | |
| 811 | * Seq_ops show method. Called several times within a read()
|
| 812 | * call from userspace, with ddebug_lock held. Formats the
|
| 813 | * current _ddebug as a single human-readable line, with a
|
| 814 | * special case for the header line.
|
| 815 |
|
| 816 | static int ddebug_proc_show(struct seq_file *m, void *p)
|
| 817 | {
|
| 818 | struct ddebug_iter *iter = m->private;
|
| 819 | struct _ddebug *dp = p;
|
| 820 | char flagsbuf[10];
|
| 821 |
|
| 822 | vpr_info("called m=%p p=%p\n", m, p);
|
| 823 |
|
| 824 | if (p == SEQ_START_TOKEN) {
|
| 825 | seq_puts(m,
|
| 826 | "# filename:lineno [module]function flags format\n");
|
| 827 | return 0;
|
| 828 | }
|
| 829 |
|
| 830 | seq_printf(m, "%s:%u [%s]%s =%s \"",
|
| 831 | trim_prefix(dp->filename), dp->lineno,
|
| 832 | iter->table->mod_name, dp->function,
|
| 833 | ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
|
| 834 | seq_escape(m, dp->format, "\t\r\n\"");
|
| 835 | seq_puts(m, "\"\n");
|
| 836 |
|
| 837 | return 0;
|
| 838 | }
|
| 839 |
|
| 840 | |
| 841 | * Seq_ops stop method. Called at the end of each read()
|
| 842 | * call from userspace. Drops ddebug_lock.
|
| 843 |
|
| 844 | static void ddebug_proc_stop(struct seq_file *m, void *p)
|
| 845 | {
|
| 846 | vpr_info("called m=%p p=%p\n", m, p);
|
| 847 | mutex_unlock(&ddebug_lock);
|
| 848 | }
|
| 849 |
|
| 850 | static const struct seq_operations ddebug_proc_seqops = {
|
| 851 | .start = ddebug_proc_start,
|
| 852 | .next = ddebug_proc_next,
|
| 853 | .show = ddebug_proc_show,
|
| 854 | .stop = ddebug_proc_stop
|
| 855 | };
|
| 856 |
|
| 857 | |
| 858 | * File_ops->open method for <debugfs>/dynamic_debug/control. Does
|
| 859 | * the seq_file setup dance, and also creates an iterator to walk the
|
| 860 | * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
|
| 861 | * files where it's not needed, as doing so simplifies the ->release
|
| 862 | * method.
|
| 863 |
|
| 864 | static int ddebug_proc_open(struct inode *inode, struct file *file)
|
| 865 | {
|
| 866 | struct ddebug_iter *iter;
|
| 867 | int err;
|
| 868 |
|
| 869 | vpr_info("called\n");
|
| 870 |
|
| 871 | iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
| 872 | if (iter == NULL)
|
| 873 | return -ENOMEM;
|
| 874 |
|
| 875 | err = seq_open(file, &ddebug_proc_seqops);
|
| 876 | if (err) {
|
| 877 | kfree(iter);
|
| 878 | return err;
|
| 879 | }
|
| 880 | ((struct seq_file *)file->private_data)->private = iter;
|
| 881 | return 0;
|
| 882 | }
|
| 883 |
|
| 884 | static const struct file_operations ddebug_proc_fops = {
|
| 885 | .owner = THIS_MODULE,
|
| 886 | .open = ddebug_proc_open,
|
| 887 | .read = seq_read,
|
| 888 | .llseek = seq_lseek,
|
| 889 | .release = seq_release_private,
|
| 890 | .write = ddebug_proc_write
|
| 891 | };
|
| 892 |
|
| 893 | |
| 894 | * Allocate a new ddebug_table for the given module
|
| 895 | * and add it to the global list.
|
| 896 |
|
| 897 | int ddebug_add_module(struct _ddebug *tab, unsigned int n,
|
| 898 | const char *name)
|
| 899 | {
|
| 900 | struct ddebug_table *dt;
|
| 901 | char *new_name;
|
| 902 |
|
| 903 | dt = kzalloc(sizeof(*dt), GFP_KERNEL);
|
| 904 | if (dt == NULL)
|
| 905 | return -ENOMEM;
|
| 906 | new_name = kstrdup(name, GFP_KERNEL);
|
| 907 | if (new_name == NULL) {
|
| 908 | kfree(dt);
|
| 909 | return -ENOMEM;
|
| 910 | }
|
| 911 | dt->mod_name = new_name;
|
| 912 | dt->num_ddebugs = n;
|
| 913 | dt->ddebugs = tab;
|
| 914 |
|
| 915 | mutex_lock(&ddebug_lock);
|
| 916 | list_add_tail(&dt->link, &ddebug_tables);
|
| 917 | mutex_unlock(&ddebug_lock);
|
| 918 |
|
| 919 | vpr_info("%u debug prints in module %s\n", n, dt->mod_name);
|
| 920 | return 0;
|
| 921 | }
|
| 922 | EXPORT_SYMBOL_GPL(ddebug_add_module);
|
| 923 |
|
| 924 |
|
| 925 | static int ddebug_dyndbg_param_cb(char *param, char *val,
|
| 926 | const char *modname, int on_err)
|
| 927 | {
|
| 928 | char *sep;
|
| 929 |
|
| 930 | sep = strchr(param, '.');
|
| 931 | if (sep) {
|
| 932 |
|
| 933 | *sep = '\0';
|
| 934 | modname = param;
|
| 935 | param = sep + 1;
|
| 936 | }
|
| 937 | if (strcmp(param, "dyndbg"))
|
| 938 | return on_err;
|
| 939 |
|
| 940 | ddebug_exec_queries((val ? val : "+p"), modname);
|
| 941 |
|
| 942 | return 0;
|
| 943 | }
|
| 944 |
|
| 945 |
|
| 946 | static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
|
| 947 | const char *unused)
|
| 948 | {
|
| 949 | vpr_info("%s=\"%s\"\n", param, val);
|
| 950 | return ddebug_dyndbg_param_cb(param, val, NULL, 0);
|
| 951 | }
|
| 952 |
|
| 953 | |
| 954 | * modprobe foo finds foo.params in boot-args, strips "foo.", and
|
| 955 | * passes them to load_module(). This callback gets unknown params,
|
| 956 | * processes dyndbg params, rejects others.
|
| 957 |
|
| 958 | int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
|
| 959 | {
|
| 960 | vpr_info("module: %s %s=\"%s\"\n", module, param, val);
|
| 961 | return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
|
| 962 | }
|
| 963 |
|
| 964 | static void ddebug_table_free(struct ddebug_table *dt)
|
| 965 | {
|
| 966 | list_del_init(&dt->link);
|
| 967 | kfree(dt->mod_name);
|
| 968 | kfree(dt);
|
| 969 | }
|
| 970 |
|
| 971 | |
| 972 | * Called in response to a module being unloaded. Removes
|
| 973 | * any ddebug_table's which point at the module.
|
| 974 |
|
| 975 | int ddebug_remove_module(const char *mod_name)
|
| 976 | {
|
| 977 | struct ddebug_table *dt, *nextdt;
|
| 978 | int ret = -ENOENT;
|
| 979 |
|
| 980 | vpr_info("removing module \"%s\"\n", mod_name);
|
| 981 |
|
| 982 | mutex_lock(&ddebug_lock);
|
| 983 | list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
|
| 984 | if (!strcmp(dt->mod_name, mod_name)) {
|
| 985 | ddebug_table_free(dt);
|
| 986 | ret = 0;
|
| 987 | }
|
| 988 | }
|
| 989 | mutex_unlock(&ddebug_lock);
|
| 990 | return ret;
|
| 991 | }
|
| 992 | EXPORT_SYMBOL_GPL(ddebug_remove_module);
|
| 993 |
|
| 994 | static void ddebug_remove_all_tables(void)
|
| 995 | {
|
| 996 | mutex_lock(&ddebug_lock);
|
| 997 | while (!list_empty(&ddebug_tables)) {
|
| 998 | struct ddebug_table *dt = list_entry(ddebug_tables.next,
|
| 999 | struct ddebug_table,
|
| 1000 | link);
|
| 1001 | ddebug_table_free(dt);
|
| 1002 | }
|
| 1003 | mutex_unlock(&ddebug_lock);
|
| 1004 | }
|
| 1005 |
|
| 1006 | static __initdata int ddebug_init_success;
|
| 1007 |
|
| 1008 | static int __init dynamic_debug_init_debugfs(void)
|
| 1009 | {
|
| 1010 | struct dentry *dir, *file;
|
| 1011 |
|
| 1012 | if (!ddebug_init_success)
|
| 1013 | return -ENODEV;
|
| 1014 |
|
| 1015 | dir = debugfs_create_dir("dynamic_debug", NULL);
|
| 1016 | if (!dir)
|
| 1017 | return -ENOMEM;
|
| 1018 | file = debugfs_create_file("control", 0644, dir, NULL,
|
| 1019 | &ddebug_proc_fops);
|
| 1020 | if (!file) {
|
| 1021 | debugfs_remove(dir);
|
| 1022 | return -ENOMEM;
|
| 1023 | }
|
| 1024 | return 0;
|
| 1025 | }
|
| 1026 |
|
| 1027 | static int __init dynamic_debug_init(void)
|
| 1028 | {
|
| 1029 | struct _ddebug *iter, *iter_start;
|
| 1030 | const char *modname = NULL;
|
| 1031 | char *cmdline;
|
| 1032 | int ret = 0;
|
| 1033 | int n = 0, entries = 0, modct = 0;
|
| 1034 | int verbose_bytes = 0;
|
| 1035 |
|
| 1036 | if (__start___verbose == __stop___verbose) {
|
| 1037 | pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
|
| 1038 | return 1;
|
| 1039 | }
|
| 1040 | iter = __start___verbose;
|
| 1041 | modname = iter->modname;
|
| 1042 | iter_start = iter;
|
| 1043 | for (; iter < __stop___verbose; iter++) {
|
| 1044 | entries++;
|
| 1045 | verbose_bytes += strlen(iter->modname) + strlen(iter->function)
|
| 1046 | + strlen(iter->filename) + strlen(iter->format);
|
| 1047 |
|
| 1048 | if (strcmp(modname, iter->modname)) {
|
| 1049 | modct++;
|
| 1050 | ret = ddebug_add_module(iter_start, n, modname);
|
| 1051 | if (ret)
|
| 1052 | goto out_err;
|
| 1053 | n = 0;
|
| 1054 | modname = iter->modname;
|
| 1055 | iter_start = iter;
|
| 1056 | }
|
| 1057 | n++;
|
| 1058 | }
|
| 1059 | ret = ddebug_add_module(iter_start, n, modname);
|
| 1060 | if (ret)
|
| 1061 | goto out_err;
|
| 1062 |
|
| 1063 | ddebug_init_success = 1;
|
| 1064 | vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
|
| 1065 | modct, entries, (int)(modct * sizeof(struct ddebug_table)),
|
| 1066 | verbose_bytes + (int)(__stop___verbose - __start___verbose));
|
| 1067 |
|
| 1068 |
|
| 1069 | if (ddebug_setup_string[0] != '\0') {
|
| 1070 | pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
|
| 1071 | ret = ddebug_exec_queries(ddebug_setup_string, NULL);
|
| 1072 | if (ret < 0)
|
| 1073 | pr_warn("Invalid ddebug boot param %s\n",
|
| 1074 | ddebug_setup_string);
|
| 1075 | else
|
| 1076 | pr_info("%d changes by ddebug_query\n", ret);
|
| 1077 | }
|
| 1078 | |
| 1079 | * again to find and activate queries given in dyndbg params.
|
| 1080 | * While this has already been done for known boot params, it
|
| 1081 | * ignored the unknown ones (dyndbg in particular). Reusing
|
| 1082 | * parse_args avoids ad-hoc parsing. This will also attempt
|
| 1083 | * to activate queries for not-yet-loaded modules, which is
|
| 1084 | * slightly noisy if verbose, but harmless.
|
| 1085 |
|
| 1086 | cmdline = kstrdup(saved_command_line, GFP_KERNEL);
|
| 1087 | parse_args("dyndbg params", cmdline, NULL,
|
| 1088 | 0, 0, 0, &ddebug_dyndbg_boot_param_cb);
|
| 1089 | kfree(cmdline);
|
| 1090 | return 0;
|
| 1091 |
|
| 1092 | out_err:
|
| 1093 | ddebug_remove_all_tables();
|
| 1094 | return 0;
|
| 1095 | }
|
| 1096 |
|
| 1097 | early_initcall(dynamic_debug_init);
|
| 1098 |
|
| 1099 |
|
| 1100 | fs_initcall(dynamic_debug_init_debugfs);
|