1 files changed, 494 insertions, 214 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b335acb43be2..c37aeacd7651 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -7,13 +7,15 @@
  * Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
  * By Greg Banks <gnb@melbourne.sgi.com>
  * Copyright (c) 2008 Silicon Graphics Inc.  All Rights Reserved.
+ * Copyright (C) 2011 Bart Van Assche.  All Rights Reserved.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/kallsyms.h>
-#include <linux/version.h>
 #include <linux/types.h>
 #include <linux/mutex.h>
 #include <linux/proc_fs.h>
@@ -22,11 +24,16 @@
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
 #include <linux/string.h>
+#include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 #include <linux/dynamic_debug.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
 #include <linux/jump_label.h>
+#include <linux/hardirq.h>
+#include <linux/sched.h>
+#include <linux/device.h>
+#include <linux/netdevice.h>
 
 extern struct _ddebug __start___verbose[];
 extern struct _ddebug __stop___verbose[];
@@ -35,7 +42,6 @@ struct ddebug_table {
 	struct list_head link;
 	char *mod_name;
 	unsigned int num_ddebugs;
-	unsigned int num_enabled;
 	struct _ddebug *ddebugs;
 };
 
@@ -54,72 +60,114 @@ struct ddebug_iter {
 
 static DEFINE_MUTEX(ddebug_lock);
 static LIST_HEAD(ddebug_tables);
-static int verbose = 0;
+static int verbose;
+module_param(verbose, int, 0644);
 
-/* Return the last part of a pathname */
-static inline const char *basename(const char *path)
+/* Return the path relative to source root */
+static inline const char *trim_prefix(const char *path)
 {
-	const char *tail = strrchr(path, '/');
-	return tail ? tail+1 : path;
+	int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
+
+	if (strncmp(path, __FILE__, skip))
+		skip = 0; /* prefix mismatch, don't skip */
+
+	return path + skip;
 }
 
+static struct { unsigned flag:8; char opt_char; } opt_array[] = {
+	{ _DPRINTK_FLAGS_PRINT, 'p' },
+	{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
+	{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
+	{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
+	{ _DPRINTK_FLAGS_INCL_TID, 't' },
+	{ _DPRINTK_FLAGS_NONE, '_' },
+};
+
 /* format a string into buf[] which describes the _ddebug's flags */
 static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
 				    size_t maxlen)
 {
 	char *p = buf;
+	int i;
 
-	BUG_ON(maxlen < 4);
-	if (dp->flags & _DPRINTK_FLAGS_PRINT)
-		*p++ = 'p';
+	BUG_ON(maxlen < 6);
+	for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
+		if (dp->flags & opt_array[i].flag)
+			*p++ = opt_array[i].opt_char;
 	if (p == buf)
-		*p++ = '-';
+		*p++ = '_';
 	*p = '\0';
 
 	return buf;
 }
 
+#define vpr_info(fmt, ...)					\
+do {								\
+	if (verbose)						\
+		pr_info(fmt, ##__VA_ARGS__);			\
+} while (0)
+
+static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
+{
+	/* trim any trailing newlines */
+	int fmtlen = 0;
+
+	if (query->format) {
+		fmtlen = strlen(query->format);
+		while (fmtlen && query->format[fmtlen - 1] == '\n')
+			fmtlen--;
+	}
+
+	vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
+		 msg,
+		 query->function ? query->function : "",
+		 query->filename ? query->filename : "",
+		 query->module ? query->module : "",
+		 fmtlen, query->format ? query->format : "",
+		 query->first_lineno, query->last_lineno);
+}
+
 /*
- * Search the tables for _ddebug's which match the given
- * `query' and apply the `flags' and `mask' to them.  Tells
- * the user which ddebug's were changed, or whether none
- * were matched.
+ * Search the tables for _ddebug's which match the given `query' and
+ * apply the `flags' and `mask' to them.  Returns number of matching
+ * callsites, normally the same as number of changes.  If verbose,
+ * logs the changes.  Takes ddebug_lock.
  */
-static void ddebug_change(const struct ddebug_query *query,
-			   unsigned int flags, unsigned int mask)
+static int ddebug_change(const struct ddebug_query *query,
+			unsigned int flags, unsigned int mask)
 {
 	int i;
 	struct ddebug_table *dt;
 	unsigned int newflags;
 	unsigned int nfound = 0;
-	char flagbuf[8];
+	char flagbuf[10];
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry(dt, &ddebug_tables, link) {
 
 		/* match against the module name */
-		if (query->module != NULL &&
-		    strcmp(query->module, dt->mod_name))
+		if (query->module && strcmp(query->module, dt->mod_name))
 			continue;
 
-		for (i = 0 ; i < dt->num_ddebugs ; i++) {
+		for (i = 0; i < dt->num_ddebugs; i++) {
 			struct _ddebug *dp = &dt->ddebugs[i];
 
 			/* match against the source filename */
-			if (query->filename != NULL &&
+			if (query->filename &&
 			    strcmp(query->filename, dp->filename) &&
-			    strcmp(query->filename, basename(dp->filename)))
+			    strcmp(query->filename, kbasename(dp->filename)) &&
+			    strcmp(query->filename, trim_prefix(dp->filename)))
 				continue;
 
 			/* match against the function */
-			if (query->function != NULL &&
+			if (query->function &&
 			    strcmp(query->function, dp->function))
 				continue;
 
 			/* match against the format */
-			if (query->format != NULL &&
-			    strstr(dp->format, query->format) == NULL)
+			if (query->format &&
+			    !strstr(dp->format, query->format))
 				continue;
 
 			/* match against the line number range */
@@ -135,29 +183,20 @@ static void ddebug_change(const struct ddebug_query *query,
 			newflags = (dp->flags & mask) | flags;
 			if (newflags == dp->flags)
 				continue;
-
-			if (!newflags)
-				dt->num_enabled--;
-			else if (!dp->flags)
-				dt->num_enabled++;
 			dp->flags = newflags;
-			if (newflags)
-				dp->enabled = 1;
-			else
-				dp->enabled = 0;
-			if (verbose)
-				printk(KERN_INFO
-					"ddebug: changed %s:%d [%s]%s %s\n",
-					dp->filename, dp->lineno,
-					dt->mod_name, dp->function,
-					ddebug_describe_flags(dp, flagbuf,
-							sizeof(flagbuf)));
+			vpr_info("changed %s:%d [%s]%s =%s\n",
+				 trim_prefix(dp->filename), dp->lineno,
+				 dt->mod_name, dp->function,
+				 ddebug_describe_flags(dp, flagbuf,
+						       sizeof(flagbuf)));
 		}
 	}
 	mutex_unlock(&ddebug_lock);
 
 	if (!nfound && verbose)
-		printk(KERN_INFO "ddebug: no matches for query\n");
+		pr_info("no matches for query\n");
+
+	return nfound;
 }
 
 /*
@@ -177,23 +216,29 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		buf = skip_spaces(buf);
 		if (!*buf)
 			break;	/* oh, it was trailing whitespace */
+		if (*buf == '#')
+			break;	/* token starts comment, skip rest of line */
 
-		/* Run `end' over a word, either whitespace separated or quoted */
+		/* find `end' of word, whitespace separated or quoted */
 		if (*buf == '"' || *buf == '\'') {
 			int quote = *buf++;
-			for (end = buf ; *end && *end != quote ; end++)
+			for (end = buf; *end && *end != quote; end++)
 				;
-			if (!*end)
+			if (!*end) {
+				pr_err("unclosed quote: %s\n", buf);
 				return -EINVAL;	/* unclosed quote */
+			}
 		} else {
-			for (end = buf ; *end && !isspace(*end) ; end++)
+			for (end = buf; *end && !isspace(*end); end++)
 				;
 			BUG_ON(end == buf);
 		}
-		/* Here `buf' is the start of the word, `end' is one past the end */
 
-		if (nwords == maxwords)
+		/* `buf' is start of word, `end' is one past its end */
+		if (nwords == maxwords) {
+			pr_err("too many words, legal max <=%d\n", maxwords);
 			return -EINVAL;	/* ran out of words[] before bytes */
+		}
 		if (*end)
 			*end++ = '\0';	/* terminate the word */
 		words[nwords++] = buf;
@@ -202,10 +247,10 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 
 	if (verbose) {
 		int i;
-		printk(KERN_INFO "%s: split into words:", __func__);
-		for (i = 0 ; i < nwords ; i++)
-			printk(" \"%s\"", words[i]);
-		printk("\n");
+		pr_info("split into words:");
+		for (i = 0; i < nwords; i++)
+			pr_cont(" \"%s\"", words[i]);
+		pr_cont("\n");
 	}
 
 	return nwords;
@@ -225,49 +270,24 @@ static inline int parse_lineno(const char *str, unsigned int *val)
 		return 0;
 	}
 	*val = simple_strtoul(str, &end, 10);
-	return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
+	if (end == NULL || end == str || *end != '\0') {
+		pr_err("bad line-number: %s\n", str);
+		return -EINVAL;
+	}
+	return 0;
 }
 
-/*
- * Undo octal escaping in a string, inplace.  This is useful to
- * allow the user to express a query which matches a format
- * containing embedded spaces.
- */
-#define isodigit(c)		((c) >= '0' && (c) <= '7')
-static char *unescape(char *str)
+static int check_set(const char **dest, char *src, char *name)
 {
-	char *in = str;
-	char *out = str;
+	int rc = 0;
 
-	while (*in) {
-		if (*in == '\\') {
-			if (in[1] == '\\') {
-				*out++ = '\\';
-				in += 2;
-				continue;
-			} else if (in[1] == 't') {
-				*out++ = '\t';
-				in += 2;
-				continue;
-			} else if (in[1] == 'n') {
-				*out++ = '\n';
-				in += 2;
-				continue;
-			} else if (isodigit(in[1]) &&
-			         isodigit(in[2]) &&
-			         isodigit(in[3])) {
-				*out++ = ((in[1] - '0')<<6) |
-				          ((in[2] - '0')<<3) |
-				          (in[3] - '0');
-				in += 4;
-				continue;
-			}
-		}
-		*out++ = *in++;
+	if (*dest) {
+		rc = -EINVAL;
+		pr_err("match-spec:%s val:%s overridden by %s\n",
+		       name, *dest, src);
 	}
-	*out = '\0';
-
-	return str;
+	*dest = src;
+	return rc;
 }
 
 /*
@@ -281,55 +301,72 @@ static char *unescape(char *str)
  * format <escaped-string-to-find-in-format>
  * line <lineno>
  * line <first-lineno>-<last-lineno> // where either may be empty
+ *
+ * Only 1 of each type is allowed.
+ * Returns 0 on success, <0 on error.
  */
 static int ddebug_parse_query(char *words[], int nwords,
-			       struct ddebug_query *query)
+			struct ddebug_query *query, const char *modname)
 {
 	unsigned int i;
+	int rc = 0;
 
 	/* check we have an even number of words */
-	if (nwords % 2 != 0)
+	if (nwords % 2 != 0) {
+		pr_err("expecting pairs of match-spec <value>\n");
 		return -EINVAL;
+	}
 	memset(query, 0, sizeof(*query));
 
-	for (i = 0 ; i < nwords ; i += 2) {
-		if (!strcmp(words[i], "func"))
-			query->function = words[i+1];
-		else if (!strcmp(words[i], "file"))
-			query->filename = words[i+1];
-		else if (!strcmp(words[i], "module"))
-			query->module = words[i+1];
-		else if (!strcmp(words[i], "format"))
-			query->format = unescape(words[i+1]);
-		else if (!strcmp(words[i], "line")) {
+	if (modname)
+		/* support $modname.dyndbg=<multiple queries> */
+		query->module = modname;
+
+	for (i = 0; i < nwords; i += 2) {
+		if (!strcmp(words[i], "func")) {
+			rc = check_set(&query->function, words[i+1], "func");
+		} else if (!strcmp(words[i], "file")) {
+			rc = check_set(&query->filename, words[i+1], "file");
+		} else if (!strcmp(words[i], "module")) {
+			rc = check_set(&query->module, words[i+1], "module");
+		} else if (!strcmp(words[i], "format")) {
+			string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
+							    UNESCAPE_OCTAL |
+							    UNESCAPE_SPECIAL);
+			rc = check_set(&query->format, words[i+1], "format");
+		} else if (!strcmp(words[i], "line")) {
 			char *first = words[i+1];
 			char *last = strchr(first, '-');
+			if (query->first_lineno || query->last_lineno) {
+				pr_err("match-spec: line used 2x\n");
+				return -EINVAL;
+			}
 			if (last)
 				*last++ = '\0';
-			if (parse_lineno(first, &query->first_lineno) < 0)
+			if (parse_lineno(first, &query->first_lineno) < 0) {
+				pr_err("line-number is <0\n");
 				return -EINVAL;
-			if (last != NULL) {
+			}
+			if (last) {
 				/* range <first>-<last> */
-				if (parse_lineno(last, &query->last_lineno) < 0)
+				if (parse_lineno(last, &query->last_lineno)
+				    < query->first_lineno) {
+					pr_err("last-line:%d < 1st-line:%d\n",
+						query->last_lineno,
+						query->first_lineno);
 					return -EINVAL;
+				}
 			} else {
 				query->last_lineno = query->first_lineno;
 			}
 		} else {
-			if (verbose)
-				printk(KERN_ERR "%s: unknown keyword \"%s\"\n",
-					__func__, words[i]);
+			pr_err("unknown keyword \"%s\"\n", words[i]);
 			return -EINVAL;
 		}
+		if (rc)
+			return rc;
 	}
-
-	if (verbose)
-		printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" "
-		       "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
-			__func__, query->function, query->filename,
-			query->module, query->format, query->first_lineno,
-			query->last_lineno);
-
+	vpr_info_dq(query, "parsed");
 	return 0;
 }
 
@@ -343,7 +380,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 			       unsigned int *maskp)
 {
 	unsigned flags = 0;
-	int op = '=';
+	int op = '=', i;
 
 	switch (*str) {
 	case '+':
@@ -352,24 +389,24 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 		op = *str++;
 		break;
 	default:
+		pr_err("bad flag-op %c, at start of %s\n", *str, str);
 		return -EINVAL;
 	}
-	if (verbose)
-		printk(KERN_INFO "%s: op='%c'\n", __func__, op);
+	vpr_info("op='%c'\n", op);
 
-	for ( ; *str ; ++str) {
-		switch (*str) {
-		case 'p':
-			flags |= _DPRINTK_FLAGS_PRINT;
-			break;
-		default:
+	for (; *str ; ++str) {
+		for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
+			if (*str == opt_array[i].opt_char) {
+				flags |= opt_array[i].flag;
+				break;
+			}
+		}
+		if (i < 0) {
+			pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
 			return -EINVAL;
 		}
 	}
-	if (flags == 0)
-		return -EINVAL;
-	if (verbose)
-		printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags);
+	vpr_info("flags=0x%x\n", flags);
 
 	/* calculate final *flagsp, *maskp according to mask and op */
 	switch (op) {
@@ -386,41 +423,223 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 		*flagsp = 0;
 		break;
 	}
-	if (verbose)
-		printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n",
-			__func__, *flagsp, *maskp);
+	vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
 	return 0;
 }
 
-static int ddebug_exec_query(char *query_string)
+static int ddebug_exec_query(char *query_string, const char *modname)
 {
 	unsigned int flags = 0, mask = 0;
 	struct ddebug_query query;
 #define MAXWORDS 9
-	int nwords;
+	int nwords, nfound;
 	char *words[MAXWORDS];
 
 	nwords = ddebug_tokenize(query_string, words, MAXWORDS);
-	if (nwords <= 0)
+	if (nwords <= 0) {
+		pr_err("tokenize failed\n");
 		return -EINVAL;
-	if (ddebug_parse_query(words, nwords-1, &query))
+	}
+	/* check flags 1st (last arg) so query is pairs of spec,val */
+	if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
+		pr_err("flags parse failed\n");
 		return -EINVAL;
-	if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
+	}
+	if (ddebug_parse_query(words, nwords-1, &query, modname)) {
+		pr_err("query parse failed\n");
 		return -EINVAL;
-
+	}
 	/* actually go and implement the change */
-	ddebug_change(&query, flags, mask);
+	nfound = ddebug_change(&query, flags, mask);
+	vpr_info_dq(&query, nfound ? "applied" : "no-match");
+
+	return nfound;
+}
+
+/* handle multiple queries in query string, continue on error, return
+   last error or number of matching callsites.  Module name is either
+   in param (for boot arg) or perhaps in query string.
+*/
+static int ddebug_exec_queries(char *query, const char *modname)
+{
+	char *split;
+	int i, errs = 0, exitcode = 0, rc, nfound = 0;
+
+	for (i = 0; query; query = split) {
+		split = strpbrk(query, ";\n");
+		if (split)
+			*split++ = '\0';
+
+		query = skip_spaces(query);
+		if (!query || !*query || *query == '#')
+			continue;
+
+		vpr_info("query %d: \"%s\"\n", i, query);
+
+		rc = ddebug_exec_query(query, modname);
+		if (rc < 0) {
+			errs++;
+			exitcode = rc;
+		} else {
+			nfound += rc;
+		}
+		i++;
+	}
+	vpr_info("processed %d queries, with %d matches, %d errs\n",
+		 i, nfound, errs);
+
+	if (exitcode)
+		return exitcode;
+	return nfound;
+}
+
+#define PREFIX_SIZE 64
+
+static int remaining(int wrote)
+{
+	if (PREFIX_SIZE - wrote > 0)
+		return PREFIX_SIZE - wrote;
 	return 0;
 }
 
-static __initdata char ddebug_setup_string[1024];
+static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
+{
+	int pos_after_tid;
+	int pos = 0;
+
+	*buf = '\0';
+
+	if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
+		if (in_interrupt())
+			pos += snprintf(buf + pos, remaining(pos), "<intr> ");
+		else
+			pos += snprintf(buf + pos, remaining(pos), "[%d] ",
+					task_pid_vnr(current));
+	}
+	pos_after_tid = pos;
+	if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
+		pos += snprintf(buf + pos, remaining(pos), "%s:",
+				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;
+}
+
+int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
+{
+	va_list args;
+	int res;
+	struct va_format vaf;
+	char buf[PREFIX_SIZE];
+
+	BUG_ON(!descriptor);
+	BUG_ON(!fmt);
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	res = printk(KERN_DEBUG "%s%pV",
+		     dynamic_emit_prefix(descriptor, buf), &vaf);
+
+	va_end(args);
+
+	return res;
+}
+EXPORT_SYMBOL(__dynamic_pr_debug);
+
+int __dynamic_dev_dbg(struct _ddebug *descriptor,
+		      const struct device *dev, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	int res;
+
+	BUG_ON(!descriptor);
+	BUG_ON(!fmt);
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	if (!dev) {
+		res = printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
+	} else {
+		char buf[PREFIX_SIZE];
+
+		res = dev_printk_emit(7, dev, "%s%s %s: %pV",
+				      dynamic_emit_prefix(descriptor, buf),
+				      dev_driver_string(dev), dev_name(dev),
+				      &vaf);
+	}
+
+	va_end(args);
+
+	return res;
+}
+EXPORT_SYMBOL(__dynamic_dev_dbg);
+
+#ifdef CONFIG_NET
+
+int __dynamic_netdev_dbg(struct _ddebug *descriptor,
+			 const struct net_device *dev, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	int res;
+
+	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];
+
+		res = dev_printk_emit(7, dev->dev.parent,
+				      "%s%s %s %s: %pV",
+				      dynamic_emit_prefix(descriptor, buf),
+				      dev_driver_string(dev->dev.parent),
+				      dev_name(dev->dev.parent),
+				      netdev_name(dev), &vaf);
+	} else if (dev) {
+		res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf);
+	} else {
+		res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
+	}
+
+	va_end(args);
+
+	return res;
+}
+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) >= 1024) {
-		pr_warning("ddebug boot param string too large\n");
+	if (strlen(str) >= DDEBUG_STRING_SIZE) {
+		pr_warn("ddebug boot param string too large\n");
 		return 0;
 	}
-	strcpy(ddebug_setup_string, str);
+	strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
 	return 1;
 }
 
@@ -430,26 +649,32 @@ __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[256];
+	char *tmpbuf;
 	int ret;
 
 	if (len == 0)
 		return 0;
-	/* we don't check *offp -- multiple writes() are allowed */
-	if (len > sizeof(tmpbuf)-1)
+	if (len > USER_BUF_PAGE - 1) {
+		pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
 		return -E2BIG;
-	if (copy_from_user(tmpbuf, ubuf, len))
+	}
+	tmpbuf = kmalloc(len + 1, GFP_KERNEL);
+	if (!tmpbuf)
+		return -ENOMEM;
+	if (copy_from_user(tmpbuf, ubuf, len)) {
+		kfree(tmpbuf);
 		return -EFAULT;
+	}
 	tmpbuf[len] = '\0';
-	if (verbose)
-		printk(KERN_INFO "%s: read %d bytes from userspace\n",
-			__func__, (int)len);
+	vpr_info("read %d bytes from userspace\n", (int)len);
 
-	ret = ddebug_exec_query(tmpbuf);
-	if (ret)
+	ret = ddebug_exec_queries(tmpbuf, NULL);
+	kfree(tmpbuf);
+	if (ret < 0)
 		return ret;
 
 	*offp += len;
@@ -508,9 +733,7 @@ static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
 	struct _ddebug *dp;
 	int n = *pos;
 
-	if (verbose)
-		printk(KERN_INFO "%s: called m=%p *pos=%lld\n",
-			__func__, m, (unsigned long long)*pos);
+	vpr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
 
 	mutex_lock(&ddebug_lock);
 
@@ -534,9 +757,8 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 	struct ddebug_iter *iter = m->private;
 	struct _ddebug *dp;
 
-	if (verbose)
-		printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n",
-			__func__, m, p, (unsigned long long)*pos);
+	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);
@@ -556,20 +778,18 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 {
 	struct ddebug_iter *iter = m->private;
 	struct _ddebug *dp = p;
-	char flagsbuf[8];
+	char flagsbuf[10];
 
-	if (verbose)
-		printk(KERN_INFO "%s: called m=%p p=%p\n",
-			__func__, m, p);
+	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");
+			 "# filename:lineno [module]function flags format\n");
 		return 0;
 	}
 
-	seq_printf(m, "%s:%u [%s]%s %s \"",
-		   dp->filename, dp->lineno,
+	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\"");
@@ -584,9 +804,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
  */
 static void ddebug_proc_stop(struct seq_file *m, void *p)
 {
-	if (verbose)
-		printk(KERN_INFO "%s: called m=%p p=%p\n",
-			__func__, m, p);
+	vpr_info("called m=%p p=%p\n", m, p);
 	mutex_unlock(&ddebug_lock);
 }
 
@@ -598,18 +816,18 @@ static const struct seq_operations ddebug_proc_seqops = {
 };
 
 /*
- * 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.
+ * 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)
 {
 	struct ddebug_iter *iter;
 	int err;
 
-	if (verbose)
-		printk(KERN_INFO "%s: called\n", __func__);
+	vpr_info("called\n");
 
 	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
 	if (iter == NULL)
@@ -620,7 +838,7 @@ static int ddebug_proc_open(struct inode *inode, struct file *file)
 		kfree(iter);
 		return err;
 	}
-	((struct seq_file *) file->private_data)->private = iter;
+	((struct seq_file *)file->private_data)->private = iter;
 	return 0;
 }
 
@@ -653,20 +871,57 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 	}
 	dt->mod_name = new_name;
 	dt->num_ddebugs = n;
-	dt->num_enabled = 0;
 	dt->ddebugs = tab;
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	if (verbose)
-		printk(KERN_INFO "%u debug prints in module %s\n",
-				 n, dt->mod_name);
+	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);
@@ -683,9 +938,7 @@ int ddebug_remove_module(const char *mod_name)
 	struct ddebug_table *dt, *nextdt;
 	int ret = -ENOENT;
 
-	if (verbose)
-		printk(KERN_INFO "%s: removing module \"%s\"\n",
-				__func__, mod_name);
+	vpr_info("removing module \"%s\"\n", mod_name);
 
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
@@ -736,46 +989,73 @@ static int __init dynamic_debug_init(void)
 {
 	struct _ddebug *iter, *iter_start;
 	const char *modname = NULL;
+	char *cmdline;
 	int ret = 0;
-	int n = 0;
-
-	if (__start___verbose != __stop___verbose) {
-		iter = __start___verbose;
-		modname = iter->modname;
-		iter_start = iter;
-		for (; iter < __stop___verbose; iter++) {
-			if (strcmp(modname, iter->modname)) {
-				ret = ddebug_add_module(iter_start, n, modname);
-				if (ret)
-					goto out_free;
-				n = 0;
-				modname = iter->modname;
-				iter_start = iter;
-			}
-			n++;
+	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;
 		}
-		ret = ddebug_add_module(iter_start, n, modname);
+		n++;
 	}
+	ret = ddebug_add_module(iter_start, n, modname);
+	if (ret)
+		goto out_err;
 
-	/* ddebug_query boot param got passed -> set it up */
+	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') {
-		ret = ddebug_exec_query(ddebug_setup_string);
-		if (ret)
-			pr_warning("Invalid ddebug boot param %s",
-				   ddebug_setup_string);
-		else
-			pr_info("ddebug initialized with string %s",
+		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_free:
-	if (ret)
-		ddebug_remove_all_tables();
-	else
-		ddebug_init_success = 1;
+out_err:
+	ddebug_remove_all_tables();
 	return 0;
 }
 /* Allow early initialization for boot messages via boot param */
-arch_initcall(dynamic_debug_init);
+early_initcall(dynamic_debug_init);
+
 /* Debugfs setup must be done later */
-module_init(dynamic_debug_init_debugfs);
+fs_initcall(dynamic_debug_init_debugfs);