On Fri, 2020-10-09 at 18:14 +0200, Borislav Petkov wrote:
> From: Borislav Petkov <[email protected]>
>
> Instruction opcode bytes spelled using the gas directive .byte should
> carry a comment above them stating which binutils version has added
> support for the instruction mnemonic so that they can be replaced with
> the mnemonic when that binutils version is equal or less than the
> minimum-supported version by the kernel.
>
> Add a check for that.
OK but several notes:
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -6858,6 +6858,18 @@ sub process {
> WARN("DUPLICATED_SYSCTL_CONST",
> "duplicated sysctl range checking value '$1',
> consider using the shared one in include/linux/sysctl.h\n" . $herecurr);
> }
> +
> +# document which binutils version supports the actual insn mnemonic so that
> the naked opcode bytes can be replaced.
> +# x86-only.
> + if ($rawline =~ /(\.byte(?:0[xX][0-9a-fA-F]+0-9a-fx,]+)/ &&
> $realfile =~ "^arch/x86/") {
Given the location, this only works on .c and .h files.
It does not work on .S files. Should it?
No need for a capture group.
Please use @ not " as all the other $realfile comparisons
use that form when expecting a /
So it looks like the regex would be more complete as:
if ($realfile =~ m@^arch/x86/@ &&
$rawline =~ /\.byte\s+(?:$Constant|(?:\\)?$Ident|"\s*$Ident)\b/) {
etc...
> + my $comment = ctx_locate_comment(0, $linenr);
A patch can modify any number of files.
This should use ctx_locate_comment($file ? 0 : $first_line, $linenr)
as checkpatch tests work on patch contexts not the entire
file before this line.
> + if (! $comment || ($comment !~ /binutils version
> [0-9.]+/(ms)) {
No need for the $!comment test
> + WARN("MISSING_BINUTILS_VERSION",
> + "Please document which binutils version
> supports these .byte-spelled\n" .
> + "\tinsn opcodes by adding \"binutils
> version <num>\" in a comment" .
> + " above them.\n" . $herecurr);
checkpatch uses only a single line output only before $herecurr
Output line length doesn't matter.
