diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index ccf0571..921d0a6 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -11,7 +11,7 @@
  * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com>
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+#define pr_fmt(fmt) "dyndbg: " fmt
 
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -39,8 +39,8 @@
 
 #include <rdma/ib_verbs.h>
 
-extern struct _ddebug __start___verbose[];
-extern struct _ddebug __stop___verbose[];
+extern struct _ddebug __start___dyndbg[];
+extern struct _ddebug __stop___dyndbg[];
 
 struct ddebug_table {
 	struct list_head link;
@@ -62,6 +62,11 @@
 	unsigned int idx;
 };
 
+struct flag_settings {
+	unsigned int flags;
+	unsigned int mask;
+};
+
 static DEFINE_MUTEX(ddebug_lock);
 static LIST_HEAD(ddebug_tables);
 static int verbose;
@@ -105,12 +110,15 @@
 	return fb->buf;
 }
 
-#define vpr_info(fmt, ...)					\
+#define vnpr_info(lvl, fmt, ...)				\
 do {								\
-	if (verbose)						\
+	if (verbose >= lvl)					\
 		pr_info(fmt, ##__VA_ARGS__);			\
 } while (0)
 
+#define vpr_info(fmt, ...)	vnpr_info(1, fmt, ##__VA_ARGS__)
+#define v2pr_info(fmt, ...)	vnpr_info(2, fmt, ##__VA_ARGS__)
+
 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 {
 	/* trim any trailing newlines */
@@ -124,10 +132,10 @@
 
 	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->function ?: "",
+		 query->filename ?: "",
+		 query->module ?: "",
+		 fmtlen, query->format ?: "",
 		 query->first_lineno, query->last_lineno);
 }
 
@@ -138,7 +146,7 @@
  * logs the changes.  Takes ddebug_lock.
  */
 static int ddebug_change(const struct ddebug_query *query,
-			unsigned int flags, unsigned int mask)
+			 struct flag_settings *modifiers)
 {
 	int i;
 	struct ddebug_table *dt;
@@ -173,9 +181,16 @@
 				continue;
 
 			/* match against the format */
-			if (query->format &&
-			    !strstr(dp->format, query->format))
-				continue;
+			if (query->format) {
+				if (*query->format == '^') {
+					char *p;
+					/* anchored search. match must be at beginning */
+					p = strstr(dp->format, query->format+1);
+					if (p != dp->format)
+						continue;
+				} else if (!strstr(dp->format, query->format))
+					continue;
+			}
 
 			/* match against the line number range */
 			if (query->first_lineno &&
@@ -187,18 +202,18 @@
 
 			nfound++;
 
-			newflags = (dp->flags & mask) | flags;
+			newflags = (dp->flags & modifiers->mask) | modifiers->flags;
 			if (newflags == dp->flags)
 				continue;
 #ifdef CONFIG_JUMP_LABEL
 			if (dp->flags & _DPRINTK_FLAGS_PRINT) {
-				if (!(flags & _DPRINTK_FLAGS_PRINT))
+				if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
 					static_branch_disable(&dp->key.dd_key_true);
-			} else if (flags & _DPRINTK_FLAGS_PRINT)
+			} else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
 				static_branch_enable(&dp->key.dd_key_true);
 #endif
 			dp->flags = newflags;
-			vpr_info("changed %s:%d [%s]%s =%s\n",
+			v2pr_info("changed %s:%d [%s]%s =%s\n",
 				 trim_prefix(dp->filename), dp->lineno,
 				 dt->mod_name, dp->function,
 				 ddebug_describe_flags(dp->flags, &fbuf));
@@ -288,6 +303,41 @@
 	return 0;
 }
 
+static int parse_linerange(struct ddebug_query *query, const char *first)
+{
+	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)
+		return -EINVAL;
+	if (last) {
+		/* range <first>-<last> */
+		if (parse_lineno(last, &query->last_lineno) < 0)
+			return -EINVAL;
+
+		/* special case for last lineno not specified */
+		if (query->last_lineno == 0)
+			query->last_lineno = UINT_MAX;
+
+		if (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;
+	}
+	vpr_info("parsed line %d-%d\n", query->first_lineno,
+		 query->last_lineno);
+	return 0;
+}
+
 static int check_set(const char **dest, char *src, char *name)
 {
 	int rc = 0;
@@ -321,61 +371,53 @@
 {
 	unsigned int i;
 	int rc = 0;
+	char *fline;
 
 	/* check we have an even number of words */
 	if (nwords % 2 != 0) {
 		pr_err("expecting pairs of match-spec <value>\n");
 		return -EINVAL;
 	}
-	memset(query, 0, sizeof(*query));
 
 	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 |
+		char *keyword = words[i];
+		char *arg = words[i+1];
+
+		if (!strcmp(keyword, "func")) {
+			rc = check_set(&query->function, arg, "func");
+		} else if (!strcmp(keyword, "file")) {
+			if (check_set(&query->filename, arg, "file"))
+				return -EINVAL;
+
+			/* tail :$info is function or line-range */
+			fline = strchr(query->filename, ':');
+			if (!fline)
+				continue;
+			*fline++ = '\0';
+			if (isalpha(*fline) || *fline == '*' || *fline == '?') {
+				/* take as function name */
+				if (check_set(&query->function, fline, "func"))
+					return -EINVAL;
+			} else {
+				if (parse_linerange(query, fline))
+					return -EINVAL;
+			}
+		} else if (!strcmp(keyword, "module")) {
+			rc = check_set(&query->module, arg, "module");
+		} else if (!strcmp(keyword, "format")) {
+			string_unescape_inplace(arg, 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");
+			rc = check_set(&query->format, arg, "format");
+		} else if (!strcmp(keyword, "line")) {
+			if (parse_linerange(query, arg))
 				return -EINVAL;
-			}
-			if (last)
-				*last++ = '\0';
-			if (parse_lineno(first, &query->first_lineno) < 0)
-				return -EINVAL;
-			if (last) {
-				/* range <first>-<last> */
-				if (parse_lineno(last, &query->last_lineno) < 0)
-					return -EINVAL;
-
-				/* special case for last lineno not specified */
-				if (query->last_lineno == 0)
-					query->last_lineno = UINT_MAX;
-
-				if (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 {
-			pr_err("unknown keyword \"%s\"\n", words[i]);
+			pr_err("unknown keyword \"%s\"\n", keyword);
 			return -EINVAL;
 		}
 		if (rc)
@@ -391,11 +433,9 @@
  * flags fields of matched _ddebug's.  Returns 0 on success
  * or <0 on error.
  */
-static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
-			       unsigned int *maskp)
+static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 {
-	unsigned flags = 0;
-	int op = '=', i;
+	int op, i;
 
 	switch (*str) {
 	case '+':
@@ -412,40 +452,40 @@
 	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;
+				modifiers->flags |= opt_array[i].flag;
 				break;
 			}
 		}
 		if (i < 0) {
-			pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
+			pr_err("unknown flag '%c'\n", *str);
 			return -EINVAL;
 		}
 	}
-	vpr_info("flags=0x%x\n", flags);
+	vpr_info("flags=0x%x\n", modifiers->flags);
 
-	/* calculate final *flagsp, *maskp according to mask and op */
+	/* calculate final flags, mask based upon op */
 	switch (op) {
 	case '=':
-		*maskp = 0;
-		*flagsp = flags;
+		/* modifiers->flags already set */
+		modifiers->mask = 0;
 		break;
 	case '+':
-		*maskp = ~0U;
-		*flagsp = flags;
+		modifiers->mask = ~0U;
 		break;
 	case '-':
-		*maskp = ~flags;
-		*flagsp = 0;
+		modifiers->mask = ~modifiers->flags;
+		modifiers->flags = 0;
 		break;
 	}
-	vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
+	vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+
 	return 0;
 }
 
 static int ddebug_exec_query(char *query_string, const char *modname)
 {
-	unsigned int flags = 0, mask = 0;
-	struct ddebug_query query;
+	struct flag_settings modifiers = {};
+	struct ddebug_query query = {};
 #define MAXWORDS 9
 	int nwords, nfound;
 	char *words[MAXWORDS];
@@ -456,7 +496,7 @@
 		return -EINVAL;
 	}
 	/* check flags 1st (last arg) so query is pairs of spec,val */
-	if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {
+	if (ddebug_parse_flags(words[nwords-1], &modifiers)) {
 		pr_err("flags parse failed\n");
 		return -EINVAL;
 	}
@@ -465,7 +505,7 @@
 		return -EINVAL;
 	}
 	/* actually go and implement the change */
-	nfound = ddebug_change(&query, flags, mask);
+	nfound = ddebug_change(&query, &modifiers);
 	vpr_info_dq(&query, nfound ? "applied" : "no-match");
 
 	return nfound;
@@ -508,6 +548,35 @@
 	return nfound;
 }
 
+/**
+ * dynamic_debug_exec_queries - select and change dynamic-debug prints
+ * @query: query-string described in admin-guide/dynamic-debug-howto
+ * @modname: string containing module name, usually &module.mod_name
+ *
+ * This uses the >/proc/dynamic_debug/control reader, allowing module
+ * authors to modify their dynamic-debug callsites. The modname is
+ * canonically struct module.mod_name, but can also be null or a
+ * module-wildcard, for example: "drm*".
+ */
+int dynamic_debug_exec_queries(const char *query, const char *modname)
+{
+	int rc;
+	char *qry; /* writable copy of query */
+
+	if (!query) {
+		pr_err("non-null query/command string expected\n");
+		return -EINVAL;
+	}
+	qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+	if (!qry)
+		return -ENOMEM;
+
+	rc = ddebug_exec_queries(qry, modname);
+	kfree(qry);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
+
 #define PREFIX_SIZE 64
 
 static int remaining(int wrote)
@@ -770,8 +839,6 @@
 	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)
@@ -794,9 +861,6 @@
 	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
@@ -817,8 +881,6 @@
 	struct _ddebug *dp = p;
 	struct flagsbuf flags;
 
-	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");
@@ -841,7 +903,6 @@
  */
 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);
 }
 
@@ -852,13 +913,6 @@
 	.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");
@@ -875,6 +929,14 @@
 	.write = ddebug_proc_write
 };
 
+static const struct proc_ops proc_fops = {
+	.proc_open = ddebug_proc_open,
+	.proc_read = seq_read,
+	.proc_lseek = seq_lseek,
+	.proc_release = seq_release_private,
+	.proc_write = ddebug_proc_write
+};
+
 /*
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
@@ -900,10 +962,10 @@
 	dt->ddebugs = tab;
 
 	mutex_lock(&ddebug_lock);
-	list_add_tail(&dt->link, &ddebug_tables);
+	list_add(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%u debug prints in module %s\n", n, dt->mod_name);
+	v2pr_info("%3u debug prints in module %s\n", n, dt->mod_name);
 	return 0;
 }
 
@@ -962,7 +1024,7 @@
 	struct ddebug_table *dt, *nextdt;
 	int ret = -ENOENT;
 
-	vpr_info("removing module \"%s\"\n", mod_name);
+	v2pr_info("removing module \"%s\"\n", mod_name);
 
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
@@ -990,15 +1052,25 @@
 
 static __initdata int ddebug_init_success;
 
-static int __init dynamic_debug_init_debugfs(void)
+static int __init dynamic_debug_init_control(void)
 {
-	struct dentry *dir;
+	struct proc_dir_entry *procfs_dir;
+	struct dentry *debugfs_dir;
 
 	if (!ddebug_init_success)
 		return -ENODEV;
 
-	dir = debugfs_create_dir("dynamic_debug", NULL);
-	debugfs_create_file("control", 0644, dir, NULL, &ddebug_proc_fops);
+	/* Create the control file in debugfs if it is enabled */
+	if (debugfs_initialized()) {
+		debugfs_dir = debugfs_create_dir("dynamic_debug", NULL);
+		debugfs_create_file("control", 0644, debugfs_dir, NULL,
+				    &ddebug_proc_fops);
+	}
+
+	/* Also create the control file in procfs */
+	procfs_dir = proc_mkdir("dynamic_debug", NULL);
+	if (procfs_dir)
+		proc_create("control", 0644, procfs_dir, &proc_fops);
 
 	return 0;
 }
@@ -1010,20 +1082,21 @@
 	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;
+	if (&__start___dyndbg == &__stop___dyndbg) {
+		if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
+			pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
+			return 1;
+		}
+		pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
+		ddebug_init_success = 1;
+		return 0;
 	}
-	iter = __start___verbose;
+	iter = __start___dyndbg;
 	modname = iter->modname;
 	iter_start = iter;
-	for (; iter < __stop___verbose; iter++) {
+	for (; iter < __stop___dyndbg; 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);
@@ -1040,9 +1113,9 @@
 		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",
+	vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in __dyndbg section\n",
 		 modct, entries, (int)(modct * sizeof(struct ddebug_table)),
-		 verbose_bytes + (int)(__stop___verbose - __start___verbose));
+		 (int)(entries * sizeof(struct _ddebug)));
 
 	/* apply ddebug_query boot param, dont unload tables on err */
 	if (ddebug_setup_string[0] != '\0') {
@@ -1076,4 +1149,4 @@
 early_initcall(dynamic_debug_init);
 
 /* Debugfs setup must be done later */
-fs_initcall(dynamic_debug_init_debugfs);
+fs_initcall(dynamic_debug_init_control);