[PATCH] checkstack: print module names

Finding "init_module" high stack usage problems is challenging when there
are over 1600 "init_module" functions in the kernel tree, so make
checkstack.pl print out the filename where the stack usage occurs.  This is
useful for code built as loadable modules.

For built-in code, it just prints the kernel image file name, like
"vmlinux".  Examples:

(before patch:)
0x0000000d callback:					1928
0xffffffff81678c09 huft_build:				1560
0x0018 init_module:					1512

(after patch:)
0x0000000d callback [divacapi]:				1928
0xffffffff81678c09 huft_build [vmlinux]:		1560
0x0018 init_module [hdaps]:				1512

Also change one if-series to use elsif to cut down on unneeded tests.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Joern Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

scripts/checkstack.pl

@@ -89,11 +89,21 @@ sub bysize($) {
 #
 my $funcre = qr/^$x* <(.*)>:$/;
 my $func;
+my $file, $lastslash;
+
 while (my $line = <STDIN>) {
 	if ($line =~ m/$funcre/) {
 		$func = $1;
 	}
-	if ($line =~ m/$re/) {
+	elsif ($line =~ m/(.*):\s*file format/) {
+		$file = $1;
+		$file =~ s/\.ko//;
+		$lastslash = rindex($file, "/");
+		if ($lastslash != -1) {
+			$file = substr($file, $lastslash + 1);
+		}
+	}
+	elsif ($line =~ m/$re/) {
 		my $size = $1;
 		$size = hex($size) if ($size =~ /^0x/);
 
@@ -109,7 +119,7 @@ while (my $line = <STDIN>) {
 		$addr =~ s/ /0/g;
 		$addr = "0x$addr";
 
-		my $intro = "$addr $func:";
+		my $intro = "$addr $func [$file]:";
 		my $padlen = 56 - length($intro);
 		while ($padlen > 0) {
 			$intro .= '	';