![Joe Perches](/assets/img/avatar_default.png)
Use #defines instead of magic values. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1044 lines
25 KiB
C
1044 lines
25 KiB
C
/*
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* lib/dynamic_debug.c
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*
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* make pr_debug()/dev_dbg() calls runtime configurable based upon their
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* source module.
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*
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* Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
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* By Greg Banks <gnb@melbourne.sgi.com>
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* Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved.
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* Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
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* Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/kallsyms.h>
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/list.h>
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#include <linux/sysctl.h>
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#include <linux/ctype.h>
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#include <linux/string.h>
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#include <linux/parser.h>
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#include <linux/string_helpers.h>
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#include <linux/uaccess.h>
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#include <linux/dynamic_debug.h>
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#include <linux/debugfs.h>
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#include <linux/slab.h>
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#include <linux/jump_label.h>
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#include <linux/hardirq.h>
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#include <linux/sched.h>
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#include <linux/device.h>
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#include <linux/netdevice.h>
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extern struct _ddebug __start___verbose[];
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extern struct _ddebug __stop___verbose[];
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struct ddebug_table {
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struct list_head link;
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char *mod_name;
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unsigned int num_ddebugs;
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struct _ddebug *ddebugs;
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};
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struct ddebug_query {
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const char *filename;
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const char *module;
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const char *function;
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const char *format;
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unsigned int first_lineno, last_lineno;
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};
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struct ddebug_iter {
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struct ddebug_table *table;
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unsigned int idx;
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};
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static DEFINE_MUTEX(ddebug_lock);
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static LIST_HEAD(ddebug_tables);
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static int verbose;
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module_param(verbose, int, 0644);
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/* Return the path relative to source root */
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static inline const char *trim_prefix(const char *path)
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{
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int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
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if (strncmp(path, __FILE__, skip))
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skip = 0; /* prefix mismatch, don't skip */
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return path + skip;
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}
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static struct { unsigned flag:8; char opt_char; } opt_array[] = {
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{ _DPRINTK_FLAGS_PRINT, 'p' },
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{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
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{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
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{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
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{ _DPRINTK_FLAGS_INCL_TID, 't' },
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{ _DPRINTK_FLAGS_NONE, '_' },
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};
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/* format a string into buf[] which describes the _ddebug's flags */
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static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
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size_t maxlen)
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{
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char *p = buf;
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int i;
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BUG_ON(maxlen < 6);
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for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
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if (dp->flags & opt_array[i].flag)
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*p++ = opt_array[i].opt_char;
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if (p == buf)
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*p++ = '_';
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*p = '\0';
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return buf;
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}
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#define vpr_info(fmt, ...) \
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do { \
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if (verbose) \
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pr_info(fmt, ##__VA_ARGS__); \
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} while (0)
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static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
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{
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/* trim any trailing newlines */
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int fmtlen = 0;
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if (query->format) {
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fmtlen = strlen(query->format);
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while (fmtlen && query->format[fmtlen - 1] == '\n')
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fmtlen--;
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}
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vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
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msg,
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query->function ? query->function : "",
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query->filename ? query->filename : "",
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query->module ? query->module : "",
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fmtlen, query->format ? query->format : "",
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query->first_lineno, query->last_lineno);
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}
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/*
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* Search the tables for _ddebug's which match the given `query' and
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* apply the `flags' and `mask' to them. Returns number of matching
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* callsites, normally the same as number of changes. If verbose,
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* logs the changes. Takes ddebug_lock.
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*/
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static int ddebug_change(const struct ddebug_query *query,
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unsigned int flags, unsigned int mask)
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{
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int i;
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struct ddebug_table *dt;
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unsigned int newflags;
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unsigned int nfound = 0;
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char flagbuf[10];
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/* search for matching ddebugs */
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mutex_lock(&ddebug_lock);
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list_for_each_entry(dt, &ddebug_tables, link) {
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/* match against the module name */
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if (query->module &&
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!match_wildcard(query->module, dt->mod_name))
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continue;
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for (i = 0; i < dt->num_ddebugs; i++) {
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struct _ddebug *dp = &dt->ddebugs[i];
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/* match against the source filename */
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if (query->filename &&
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!match_wildcard(query->filename, dp->filename) &&
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!match_wildcard(query->filename,
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kbasename(dp->filename)) &&
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!match_wildcard(query->filename,
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trim_prefix(dp->filename)))
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continue;
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/* match against the function */
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if (query->function &&
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!match_wildcard(query->function, dp->function))
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continue;
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/* match against the format */
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if (query->format &&
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!strstr(dp->format, query->format))
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continue;
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/* match against the line number range */
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if (query->first_lineno &&
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dp->lineno < query->first_lineno)
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continue;
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if (query->last_lineno &&
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dp->lineno > query->last_lineno)
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continue;
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nfound++;
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newflags = (dp->flags & mask) | flags;
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if (newflags == dp->flags)
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continue;
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dp->flags = newflags;
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vpr_info("changed %s:%d [%s]%s =%s\n",
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trim_prefix(dp->filename), dp->lineno,
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dt->mod_name, dp->function,
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ddebug_describe_flags(dp, flagbuf,
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sizeof(flagbuf)));
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}
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}
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mutex_unlock(&ddebug_lock);
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if (!nfound && verbose)
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pr_info("no matches for query\n");
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return nfound;
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}
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/*
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* Split the buffer `buf' into space-separated words.
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* Handles simple " and ' quoting, i.e. without nested,
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* embedded or escaped \". Return the number of words
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* or <0 on error.
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*/
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static int ddebug_tokenize(char *buf, char *words[], int maxwords)
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{
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int nwords = 0;
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while (*buf) {
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char *end;
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/* Skip leading whitespace */
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buf = skip_spaces(buf);
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if (!*buf)
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break; /* oh, it was trailing whitespace */
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if (*buf == '#')
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break; /* token starts comment, skip rest of line */
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/* find `end' of word, whitespace separated or quoted */
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if (*buf == '"' || *buf == '\'') {
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int quote = *buf++;
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for (end = buf; *end && *end != quote; end++)
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;
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if (!*end) {
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pr_err("unclosed quote: %s\n", buf);
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return -EINVAL; /* unclosed quote */
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}
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} else {
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for (end = buf; *end && !isspace(*end); end++)
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;
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BUG_ON(end == buf);
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}
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/* `buf' is start of word, `end' is one past its end */
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if (nwords == maxwords) {
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pr_err("too many words, legal max <=%d\n", maxwords);
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return -EINVAL; /* ran out of words[] before bytes */
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}
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if (*end)
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*end++ = '\0'; /* terminate the word */
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words[nwords++] = buf;
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buf = end;
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}
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if (verbose) {
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int i;
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pr_info("split into words:");
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for (i = 0; i < nwords; i++)
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pr_cont(" \"%s\"", words[i]);
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pr_cont("\n");
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}
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return nwords;
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}
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/*
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* Parse a single line number. Note that the empty string ""
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* is treated as a special case and converted to zero, which
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* is later treated as a "don't care" value.
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*/
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static inline int parse_lineno(const char *str, unsigned int *val)
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{
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BUG_ON(str == NULL);
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if (*str == '\0') {
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*val = 0;
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return 0;
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}
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if (kstrtouint(str, 10, val) < 0) {
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pr_err("bad line-number: %s\n", str);
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return -EINVAL;
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}
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return 0;
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}
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static int check_set(const char **dest, char *src, char *name)
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{
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int rc = 0;
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if (*dest) {
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rc = -EINVAL;
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pr_err("match-spec:%s val:%s overridden by %s\n",
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name, *dest, src);
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}
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*dest = src;
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return rc;
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}
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/*
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* Parse words[] as a ddebug query specification, which is a series
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* of (keyword, value) pairs chosen from these possibilities:
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*
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* func <function-name>
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* file <full-pathname>
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* file <base-filename>
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* module <module-name>
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* format <escaped-string-to-find-in-format>
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* line <lineno>
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* line <first-lineno>-<last-lineno> // where either may be empty
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*
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* Only 1 of each type is allowed.
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* Returns 0 on success, <0 on error.
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*/
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static int ddebug_parse_query(char *words[], int nwords,
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struct ddebug_query *query, const char *modname)
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{
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unsigned int i;
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int rc = 0;
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/* check we have an even number of words */
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if (nwords % 2 != 0) {
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pr_err("expecting pairs of match-spec <value>\n");
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return -EINVAL;
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}
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memset(query, 0, sizeof(*query));
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if (modname)
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/* support $modname.dyndbg=<multiple queries> */
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query->module = modname;
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for (i = 0; i < nwords; i += 2) {
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if (!strcmp(words[i], "func")) {
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rc = check_set(&query->function, words[i+1], "func");
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} else if (!strcmp(words[i], "file")) {
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rc = check_set(&query->filename, words[i+1], "file");
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} else if (!strcmp(words[i], "module")) {
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rc = check_set(&query->module, words[i+1], "module");
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} else if (!strcmp(words[i], "format")) {
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string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
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UNESCAPE_OCTAL |
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UNESCAPE_SPECIAL);
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rc = check_set(&query->format, words[i+1], "format");
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} else if (!strcmp(words[i], "line")) {
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char *first = words[i+1];
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char *last = strchr(first, '-');
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if (query->first_lineno || query->last_lineno) {
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pr_err("match-spec: line used 2x\n");
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return -EINVAL;
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}
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if (last)
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*last++ = '\0';
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if (parse_lineno(first, &query->first_lineno) < 0)
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return -EINVAL;
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if (last) {
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/* range <first>-<last> */
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if (parse_lineno(last, &query->last_lineno) < 0)
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return -EINVAL;
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if (query->last_lineno < query->first_lineno) {
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pr_err("last-line:%d < 1st-line:%d\n",
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query->last_lineno,
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query->first_lineno);
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return -EINVAL;
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}
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} else {
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query->last_lineno = query->first_lineno;
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}
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} else {
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pr_err("unknown keyword \"%s\"\n", words[i]);
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return -EINVAL;
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}
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if (rc)
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return rc;
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}
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vpr_info_dq(query, "parsed");
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return 0;
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}
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/*
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* Parse `str' as a flags specification, format [-+=][p]+.
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* Sets up *maskp and *flagsp to be used when changing the
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* flags fields of matched _ddebug's. Returns 0 on success
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* or <0 on error.
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*/
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static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
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unsigned int *maskp)
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{
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unsigned flags = 0;
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int op = '=', i;
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switch (*str) {
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case '+':
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case '-':
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case '=':
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op = *str++;
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break;
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default:
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pr_err("bad flag-op %c, at start of %s\n", *str, str);
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return -EINVAL;
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}
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vpr_info("op='%c'\n", op);
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for (; *str ; ++str) {
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for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
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if (*str == opt_array[i].opt_char) {
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flags |= opt_array[i].flag;
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break;
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}
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}
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if (i < 0) {
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pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
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return -EINVAL;
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}
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}
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vpr_info("flags=0x%x\n", flags);
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/* calculate final *flagsp, *maskp according to mask and op */
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switch (op) {
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case '=':
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*maskp = 0;
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*flagsp = flags;
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break;
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case '+':
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*maskp = ~0U;
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*flagsp = flags;
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break;
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case '-':
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*maskp = ~flags;
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*flagsp = 0;
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break;
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}
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vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
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return 0;
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}
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static int ddebug_exec_query(char *query_string, const char *modname)
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{
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unsigned int flags = 0, mask = 0;
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struct ddebug_query query;
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#define MAXWORDS 9
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int nwords, nfound;
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char *words[MAXWORDS];
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nwords = ddebug_tokenize(query_string, words, MAXWORDS);
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if (nwords <= 0) {
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pr_err("tokenize failed\n");
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return -EINVAL;
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}
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/* check flags 1st (last arg) so query is pairs of spec,val */
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if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
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pr_err("flags parse failed\n");
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return -EINVAL;
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}
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if (ddebug_parse_query(words, nwords-1, &query, modname)) {
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pr_err("query parse failed\n");
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return -EINVAL;
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}
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/* actually go and implement the change */
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nfound = ddebug_change(&query, flags, mask);
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vpr_info_dq(&query, nfound ? "applied" : "no-match");
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return nfound;
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}
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/* handle multiple queries in query string, continue on error, return
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last error or number of matching callsites. Module name is either
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in param (for boot arg) or perhaps in query string.
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*/
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static int ddebug_exec_queries(char *query, const char *modname)
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{
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char *split;
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int i, errs = 0, exitcode = 0, rc, nfound = 0;
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for (i = 0; query; query = split) {
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split = strpbrk(query, ";\n");
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if (split)
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*split++ = '\0';
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query = skip_spaces(query);
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if (!query || !*query || *query == '#')
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continue;
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vpr_info("query %d: \"%s\"\n", i, query);
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rc = ddebug_exec_query(query, modname);
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if (rc < 0) {
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errs++;
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exitcode = rc;
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} else {
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nfound += rc;
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}
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i++;
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}
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vpr_info("processed %d queries, with %d matches, %d errs\n",
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i, nfound, errs);
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if (exitcode)
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return exitcode;
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return nfound;
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}
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#define PREFIX_SIZE 64
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static int remaining(int wrote)
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{
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if (PREFIX_SIZE - wrote > 0)
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return PREFIX_SIZE - wrote;
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return 0;
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}
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static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
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{
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int pos_after_tid;
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int pos = 0;
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*buf = '\0';
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if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
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if (in_interrupt())
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pos += snprintf(buf + pos, remaining(pos), "<intr> ");
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else
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pos += snprintf(buf + pos, remaining(pos), "[%d] ",
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task_pid_vnr(current));
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}
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pos_after_tid = pos;
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if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
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pos += snprintf(buf + pos, remaining(pos), "%s:",
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desc->modname);
|
|
if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
|
|
pos += snprintf(buf + pos, remaining(pos), "%s:",
|
|
desc->function);
|
|
if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
|
|
pos += snprintf(buf + pos, remaining(pos), "%d:",
|
|
desc->lineno);
|
|
if (pos - pos_after_tid)
|
|
pos += snprintf(buf + pos, remaining(pos), " ");
|
|
if (pos >= PREFIX_SIZE)
|
|
buf[PREFIX_SIZE - 1] = '\0';
|
|
|
|
return buf;
|
|
}
|
|
|
|
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
struct va_format vaf;
|
|
char buf[PREFIX_SIZE];
|
|
|
|
BUG_ON(!descriptor);
|
|
BUG_ON(!fmt);
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
printk(KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
|
|
|
|
va_end(args);
|
|
}
|
|
EXPORT_SYMBOL(__dynamic_pr_debug);
|
|
|
|
void __dynamic_dev_dbg(struct _ddebug *descriptor,
|
|
const struct device *dev, const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
BUG_ON(!descriptor);
|
|
BUG_ON(!fmt);
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
if (!dev) {
|
|
printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
|
|
} else {
|
|
char buf[PREFIX_SIZE];
|
|
|
|
dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",
|
|
dynamic_emit_prefix(descriptor, buf),
|
|
dev_driver_string(dev), dev_name(dev),
|
|
&vaf);
|
|
}
|
|
|
|
va_end(args);
|
|
}
|
|
EXPORT_SYMBOL(__dynamic_dev_dbg);
|
|
|
|
#ifdef CONFIG_NET
|
|
|
|
void __dynamic_netdev_dbg(struct _ddebug *descriptor,
|
|
const struct net_device *dev, const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
BUG_ON(!descriptor);
|
|
BUG_ON(!fmt);
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
if (dev && dev->dev.parent) {
|
|
char buf[PREFIX_SIZE];
|
|
|
|
dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,
|
|
"%s%s %s %s%s: %pV",
|
|
dynamic_emit_prefix(descriptor, buf),
|
|
dev_driver_string(dev->dev.parent),
|
|
dev_name(dev->dev.parent),
|
|
netdev_name(dev), netdev_reg_state(dev),
|
|
&vaf);
|
|
} else if (dev) {
|
|
printk(KERN_DEBUG "%s%s: %pV", netdev_name(dev),
|
|
netdev_reg_state(dev), &vaf);
|
|
} else {
|
|
printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
|
|
}
|
|
|
|
va_end(args);
|
|
}
|
|
EXPORT_SYMBOL(__dynamic_netdev_dbg);
|
|
|
|
#endif
|
|
|
|
#define DDEBUG_STRING_SIZE 1024
|
|
static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
|
|
|
|
static __init int ddebug_setup_query(char *str)
|
|
{
|
|
if (strlen(str) >= DDEBUG_STRING_SIZE) {
|
|
pr_warn("ddebug boot param string too large\n");
|
|
return 0;
|
|
}
|
|
strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
|
|
return 1;
|
|
}
|
|
|
|
__setup("ddebug_query=", ddebug_setup_query);
|
|
|
|
/*
|
|
* File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
|
|
* command text from userspace, parses and executes it.
|
|
*/
|
|
#define USER_BUF_PAGE 4096
|
|
static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
|
|
size_t len, loff_t *offp)
|
|
{
|
|
char *tmpbuf;
|
|
int ret;
|
|
|
|
if (len == 0)
|
|
return 0;
|
|
if (len > USER_BUF_PAGE - 1) {
|
|
pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
|
|
return -E2BIG;
|
|
}
|
|
tmpbuf = kmalloc(len + 1, GFP_KERNEL);
|
|
if (!tmpbuf)
|
|
return -ENOMEM;
|
|
if (copy_from_user(tmpbuf, ubuf, len)) {
|
|
kfree(tmpbuf);
|
|
return -EFAULT;
|
|
}
|
|
tmpbuf[len] = '\0';
|
|
vpr_info("read %d bytes from userspace\n", (int)len);
|
|
|
|
ret = ddebug_exec_queries(tmpbuf, NULL);
|
|
kfree(tmpbuf);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*offp += len;
|
|
return len;
|
|
}
|
|
|
|
/*
|
|
* Set the iterator to point to the first _ddebug object
|
|
* and return a pointer to that first object. Returns
|
|
* NULL if there are no _ddebugs at all.
|
|
*/
|
|
static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
|
|
{
|
|
if (list_empty(&ddebug_tables)) {
|
|
iter->table = NULL;
|
|
iter->idx = 0;
|
|
return NULL;
|
|
}
|
|
iter->table = list_entry(ddebug_tables.next,
|
|
struct ddebug_table, link);
|
|
iter->idx = 0;
|
|
return &iter->table->ddebugs[iter->idx];
|
|
}
|
|
|
|
/*
|
|
* Advance the iterator to point to the next _ddebug
|
|
* object from the one the iterator currently points at,
|
|
* and returns a pointer to the new _ddebug. Returns
|
|
* NULL if the iterator has seen all the _ddebugs.
|
|
*/
|
|
static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
|
|
{
|
|
if (iter->table == NULL)
|
|
return NULL;
|
|
if (++iter->idx == iter->table->num_ddebugs) {
|
|
/* iterate to next table */
|
|
iter->idx = 0;
|
|
if (list_is_last(&iter->table->link, &ddebug_tables)) {
|
|
iter->table = NULL;
|
|
return NULL;
|
|
}
|
|
iter->table = list_entry(iter->table->link.next,
|
|
struct ddebug_table, link);
|
|
}
|
|
return &iter->table->ddebugs[iter->idx];
|
|
}
|
|
|
|
/*
|
|
* Seq_ops start method. Called at the start of every
|
|
* read() call from userspace. Takes the ddebug_lock and
|
|
* seeks the seq_file's iterator to the given position.
|
|
*/
|
|
static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct ddebug_iter *iter = m->private;
|
|
struct _ddebug *dp;
|
|
int n = *pos;
|
|
|
|
vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
|
|
|
|
mutex_lock(&ddebug_lock);
|
|
|
|
if (!n)
|
|
return SEQ_START_TOKEN;
|
|
if (n < 0)
|
|
return NULL;
|
|
dp = ddebug_iter_first(iter);
|
|
while (dp != NULL && --n > 0)
|
|
dp = ddebug_iter_next(iter);
|
|
return dp;
|
|
}
|
|
|
|
/*
|
|
* Seq_ops next method. Called several times within a read()
|
|
* call from userspace, with ddebug_lock held. Walks to the
|
|
* next _ddebug object with a special case for the header line.
|
|
*/
|
|
static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
struct ddebug_iter *iter = m->private;
|
|
struct _ddebug *dp;
|
|
|
|
vpr_info("called m=%p p=%p *pos=%lld\n",
|
|
m, p, (unsigned long long)*pos);
|
|
|
|
if (p == SEQ_START_TOKEN)
|
|
dp = ddebug_iter_first(iter);
|
|
else
|
|
dp = ddebug_iter_next(iter);
|
|
++*pos;
|
|
return dp;
|
|
}
|
|
|
|
/*
|
|
* Seq_ops show method. Called several times within a read()
|
|
* call from userspace, with ddebug_lock held. Formats the
|
|
* current _ddebug as a single human-readable line, with a
|
|
* special case for the header line.
|
|
*/
|
|
static int ddebug_proc_show(struct seq_file *m, void *p)
|
|
{
|
|
struct ddebug_iter *iter = m->private;
|
|
struct _ddebug *dp = p;
|
|
char flagsbuf[10];
|
|
|
|
vpr_info("called m=%p p=%p\n", m, p);
|
|
|
|
if (p == SEQ_START_TOKEN) {
|
|
seq_puts(m,
|
|
"# filename:lineno [module]function flags format\n");
|
|
return 0;
|
|
}
|
|
|
|
seq_printf(m, "%s:%u [%s]%s =%s \"",
|
|
trim_prefix(dp->filename), dp->lineno,
|
|
iter->table->mod_name, dp->function,
|
|
ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
|
|
seq_escape(m, dp->format, "\t\r\n\"");
|
|
seq_puts(m, "\"\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Seq_ops stop method. Called at the end of each read()
|
|
* call from userspace. Drops ddebug_lock.
|
|
*/
|
|
static void ddebug_proc_stop(struct seq_file *m, void *p)
|
|
{
|
|
vpr_info("called m=%p p=%p\n", m, p);
|
|
mutex_unlock(&ddebug_lock);
|
|
}
|
|
|
|
static const struct seq_operations ddebug_proc_seqops = {
|
|
.start = ddebug_proc_start,
|
|
.next = ddebug_proc_next,
|
|
.show = ddebug_proc_show,
|
|
.stop = ddebug_proc_stop
|
|
};
|
|
|
|
/*
|
|
* File_ops->open method for <debugfs>/dynamic_debug/control. Does
|
|
* the seq_file setup dance, and also creates an iterator to walk the
|
|
* _ddebugs. Note that we create a seq_file always, even for O_WRONLY
|
|
* files where it's not needed, as doing so simplifies the ->release
|
|
* method.
|
|
*/
|
|
static int ddebug_proc_open(struct inode *inode, struct file *file)
|
|
{
|
|
vpr_info("called\n");
|
|
return seq_open_private(file, &ddebug_proc_seqops,
|
|
sizeof(struct ddebug_iter));
|
|
}
|
|
|
|
static const struct file_operations ddebug_proc_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = ddebug_proc_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_private,
|
|
.write = ddebug_proc_write
|
|
};
|
|
|
|
/*
|
|
* Allocate a new ddebug_table for the given module
|
|
* and add it to the global list.
|
|
*/
|
|
int ddebug_add_module(struct _ddebug *tab, unsigned int n,
|
|
const char *name)
|
|
{
|
|
struct ddebug_table *dt;
|
|
char *new_name;
|
|
|
|
dt = kzalloc(sizeof(*dt), GFP_KERNEL);
|
|
if (dt == NULL)
|
|
return -ENOMEM;
|
|
new_name = kstrdup(name, GFP_KERNEL);
|
|
if (new_name == NULL) {
|
|
kfree(dt);
|
|
return -ENOMEM;
|
|
}
|
|
dt->mod_name = new_name;
|
|
dt->num_ddebugs = n;
|
|
dt->ddebugs = tab;
|
|
|
|
mutex_lock(&ddebug_lock);
|
|
list_add_tail(&dt->link, &ddebug_tables);
|
|
mutex_unlock(&ddebug_lock);
|
|
|
|
vpr_info("%u debug prints in module %s\n", n, dt->mod_name);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ddebug_add_module);
|
|
|
|
/* helper for ddebug_dyndbg_(boot|module)_param_cb */
|
|
static int ddebug_dyndbg_param_cb(char *param, char *val,
|
|
const char *modname, int on_err)
|
|
{
|
|
char *sep;
|
|
|
|
sep = strchr(param, '.');
|
|
if (sep) {
|
|
/* needed only for ddebug_dyndbg_boot_param_cb */
|
|
*sep = '\0';
|
|
modname = param;
|
|
param = sep + 1;
|
|
}
|
|
if (strcmp(param, "dyndbg"))
|
|
return on_err; /* determined by caller */
|
|
|
|
ddebug_exec_queries((val ? val : "+p"), modname);
|
|
|
|
return 0; /* query failure shouldnt stop module load */
|
|
}
|
|
|
|
/* handle both dyndbg and $module.dyndbg params at boot */
|
|
static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
|
|
const char *unused)
|
|
{
|
|
vpr_info("%s=\"%s\"\n", param, val);
|
|
return ddebug_dyndbg_param_cb(param, val, NULL, 0);
|
|
}
|
|
|
|
/*
|
|
* modprobe foo finds foo.params in boot-args, strips "foo.", and
|
|
* passes them to load_module(). This callback gets unknown params,
|
|
* processes dyndbg params, rejects others.
|
|
*/
|
|
int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
|
|
{
|
|
vpr_info("module: %s %s=\"%s\"\n", module, param, val);
|
|
return ddebug_dyndbg_param_cb(param, val, module, -ENOENT);
|
|
}
|
|
|
|
static void ddebug_table_free(struct ddebug_table *dt)
|
|
{
|
|
list_del_init(&dt->link);
|
|
kfree(dt->mod_name);
|
|
kfree(dt);
|
|
}
|
|
|
|
/*
|
|
* Called in response to a module being unloaded. Removes
|
|
* any ddebug_table's which point at the module.
|
|
*/
|
|
int ddebug_remove_module(const char *mod_name)
|
|
{
|
|
struct ddebug_table *dt, *nextdt;
|
|
int ret = -ENOENT;
|
|
|
|
vpr_info("removing module \"%s\"\n", mod_name);
|
|
|
|
mutex_lock(&ddebug_lock);
|
|
list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
|
|
if (!strcmp(dt->mod_name, mod_name)) {
|
|
ddebug_table_free(dt);
|
|
ret = 0;
|
|
}
|
|
}
|
|
mutex_unlock(&ddebug_lock);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ddebug_remove_module);
|
|
|
|
static void ddebug_remove_all_tables(void)
|
|
{
|
|
mutex_lock(&ddebug_lock);
|
|
while (!list_empty(&ddebug_tables)) {
|
|
struct ddebug_table *dt = list_entry(ddebug_tables.next,
|
|
struct ddebug_table,
|
|
link);
|
|
ddebug_table_free(dt);
|
|
}
|
|
mutex_unlock(&ddebug_lock);
|
|
}
|
|
|
|
static __initdata int ddebug_init_success;
|
|
|
|
static int __init dynamic_debug_init_debugfs(void)
|
|
{
|
|
struct dentry *dir, *file;
|
|
|
|
if (!ddebug_init_success)
|
|
return -ENODEV;
|
|
|
|
dir = debugfs_create_dir("dynamic_debug", NULL);
|
|
if (!dir)
|
|
return -ENOMEM;
|
|
file = debugfs_create_file("control", 0644, dir, NULL,
|
|
&ddebug_proc_fops);
|
|
if (!file) {
|
|
debugfs_remove(dir);
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int __init dynamic_debug_init(void)
|
|
{
|
|
struct _ddebug *iter, *iter_start;
|
|
const char *modname = NULL;
|
|
char *cmdline;
|
|
int ret = 0;
|
|
int n = 0, entries = 0, modct = 0;
|
|
int verbose_bytes = 0;
|
|
|
|
if (__start___verbose == __stop___verbose) {
|
|
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
|
|
return 1;
|
|
}
|
|
iter = __start___verbose;
|
|
modname = iter->modname;
|
|
iter_start = iter;
|
|
for (; iter < __stop___verbose; iter++) {
|
|
entries++;
|
|
verbose_bytes += strlen(iter->modname) + strlen(iter->function)
|
|
+ strlen(iter->filename) + strlen(iter->format);
|
|
|
|
if (strcmp(modname, iter->modname)) {
|
|
modct++;
|
|
ret = ddebug_add_module(iter_start, n, modname);
|
|
if (ret)
|
|
goto out_err;
|
|
n = 0;
|
|
modname = iter->modname;
|
|
iter_start = iter;
|
|
}
|
|
n++;
|
|
}
|
|
ret = ddebug_add_module(iter_start, n, modname);
|
|
if (ret)
|
|
goto out_err;
|
|
|
|
ddebug_init_success = 1;
|
|
vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
|
|
modct, entries, (int)(modct * sizeof(struct ddebug_table)),
|
|
verbose_bytes + (int)(__stop___verbose - __start___verbose));
|
|
|
|
/* apply ddebug_query boot param, dont unload tables on err */
|
|
if (ddebug_setup_string[0] != '\0') {
|
|
pr_warn("ddebug_query param name is deprecated, change it to dyndbg\n");
|
|
ret = ddebug_exec_queries(ddebug_setup_string, NULL);
|
|
if (ret < 0)
|
|
pr_warn("Invalid ddebug boot param %s\n",
|
|
ddebug_setup_string);
|
|
else
|
|
pr_info("%d changes by ddebug_query\n", ret);
|
|
}
|
|
/* now that ddebug tables are loaded, process all boot args
|
|
* again to find and activate queries given in dyndbg params.
|
|
* While this has already been done for known boot params, it
|
|
* ignored the unknown ones (dyndbg in particular). Reusing
|
|
* parse_args avoids ad-hoc parsing. This will also attempt
|
|
* to activate queries for not-yet-loaded modules, which is
|
|
* slightly noisy if verbose, but harmless.
|
|
*/
|
|
cmdline = kstrdup(saved_command_line, GFP_KERNEL);
|
|
parse_args("dyndbg params", cmdline, NULL,
|
|
0, 0, 0, &ddebug_dyndbg_boot_param_cb);
|
|
kfree(cmdline);
|
|
return 0;
|
|
|
|
out_err:
|
|
ddebug_remove_all_tables();
|
|
return 0;
|
|
}
|
|
/* Allow early initialization for boot messages via boot param */
|
|
early_initcall(dynamic_debug_init);
|
|
|
|
/* Debugfs setup must be done later */
|
|
fs_initcall(dynamic_debug_init_debugfs);
|