1 files changed, 19 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/mkcapflags.pl b/arch/x86/kernel/cpu/mkcapflags.pl
index dfea390e1608..c7b3fe2d72e0 100644
--- a/arch/x86/kernel/cpu/mkcapflags.pl
+++ b/arch/x86/kernel/cpu/mkcapflags.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/perl -w
 #
 # Generate the x86_cap_flags[] array from include/asm-x86/cpufeature.h
 #
@@ -11,22 +11,35 @@ open(OUT, "> $out\0") or die "$0: cannot create: $out: $!\n";
 print OUT "#include <asm/cpufeature.h>\n\n";
 print OUT "const char * const x86_cap_flags[NCAPINTS*32] = {\n";
 
+%features = ();
+$err = 0;
+
 while (defined($line = <IN>)) {
         if ($line =~ /^\s*\#\s*define\s+(X86_FEATURE_(\S+))\s+(.*)$/) {
                 $macro = $1;
-                $feature = $2;
+                $feature = "\L$2";
                 $tail = $3;
                 if ($tail =~ /\/\*\s*\"([^"]*)\".*\*\//) {
-                        $feature = $1;
+                        $feature = "\L$1";
                 }
 
-                if ($feature ne '') {
-                        printf OUT "\t%-32s = \"%s\",\n",
-                                "[$macro]", "\L$feature";
+                next if ($feature eq '');
+
+                if ($features{$feature}++) {
+                        print STDERR "$in: duplicate feature name: $feature\n";
+                        $err++;
                 }
+                printf OUT "\t%-32s = \"%s\",\n", "[$macro]", $feature;
         }
 }
 print OUT "};\n";
 
 close(IN);
 close(OUT);
+
+if ($err) {
+        unlink($out);
+        exit(1);
+}
+
+exit(0);