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x86, cpufeature: Catch duplicate CPU feature strings

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We had a case of duplicate CPU feature strings, a user space ABI
violation, for almost two years.  Make it a build error so that
doesn't happen again.

Link: http://lkml.kernel.org/r/4FE34BCB.5050305@linux.intel.com
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
H. Peter Anvin 2012-06-22 11:47:15 -07:00
commit 55f6cb9d0b
1 changed files with 18 additions and 5 deletions
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23
arch/x86/kernel/cpu/mkcapflags.pl
View file

@ -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 "#include <asm/cpufeature.h>\n\n";
print OUT "const char * const x86_cap_flags[NCAPINTS*32] = {\n"; print OUT "const char * const x86_cap_flags[NCAPINTS*32] = {\n";
%features = ();
$err = 0;
while (defined($line = <IN>)) { while (defined($line = <IN>)) {
if ($line =~ /^\s*\#\s*define\s+(X86_FEATURE_(\S+))\s+(.*)$/) { if ($line =~ /^\s*\#\s*define\s+(X86_FEATURE_(\S+))\s+(.*)$/) {
$macro = $1; $macro = $1;
$feature = $2; $feature = "\L$2";
$tail = $3; $tail = $3;
if ($tail =~ /\/\*\s*\"([^"]*)\".*\*\//) { if ($tail =~ /\/\*\s*\"([^"]*)\".*\*\//) {
$feature = $1; $feature = "\L$1";
} }
if ($feature ne '') { next if ($feature eq '');
printf OUT "\t%-32s = \"%s\",\n",
"[$macro]", "\L$feature"; if ($features{$feature}++) {
print STDERR "$in: duplicate feature name: $feature\n";
$err++;
} }
printf OUT "\t%-32s = \"%s\",%s\n", "[$macro]", $feature;
} }
} }
print OUT "};\n"; print OUT "};\n";
close(IN); close(IN);
close(OUT); close(OUT);
if ($err) {
unlink($out);
exit(1);
}
exit(0);