dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'

Accept these additional query forms:

   echo "file $filestr +_" > control

       path/to/file.c:100	# as from control, column 1
       path/to/file.c:1-100	# or any legal line-range
       path/to/file.c:func_A	# as from an editor/browser
       path/to/file.c:drm_*	# wildcards still work
       path/to/file.c:*_foo	# lead wildcard too

1st 2 examples are treated as line-ranges, 3-5 are treated as func's

Doc these changes, and sprinkle in a few extra wild-card examples and
trailing # explanation texts.

Acked-by: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-14-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/admin-guide/dynamic-debug-howto.rst

@@ -164,6 +164,7 @@ func
     of each callsite.  Example::
 
 	func svc_tcp_accept
+	func *recv*		# in rfcomm, bluetooth, ping, tcp
 
 file
     The given string is compared against either the src-root relative
@@ -172,6 +173,9 @@ file
 
 	file svcsock.c
 	file kernel/freezer.c	# ie column 1 of control file
+	file drivers/usb/*	# all callsites under it
+	file inode.c:start_*	# parse :tail as a func (above)
+	file inode.c:1-100	# parse :tail as a line-range (above)
 
 module
     The given string is compared against the module name
@@ -181,6 +185,7 @@ module
 
 	module sunrpc
 	module nfsd
+	module drm*	# both drm, drm_kms_helper
 
 format
     The given string is searched for in the dynamic debug format

lib/dynamic_debug.c

@@ -359,6 +359,7 @@ static int ddebug_parse_query(char *words[], int nwords,
 {
 	unsigned int i;
 	int rc = 0;
+	char *fline;
 
 	/* check we have an even number of words */
 	if (nwords % 2 != 0) {
@@ -374,7 +375,22 @@ static int ddebug_parse_query(char *words[], int nwords,
 		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");
+			if (check_set(&query->filename, words[i+1], "file"))
+				return -EINVAL;
+
+			/* tail :$info is function or line-range */
+			fline = strchr(query->filename, ':');
+			if (!fline)
+				break;
+			*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(words[i], "module")) {
 			rc = check_set(&query->module, words[i+1], "module");
 		} else if (!strcmp(words[i], "format")) {