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. Requested-by: Peter Zijlstra <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> --- scripts/checkpatch.pl | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 504d2e431c60..e9ead600d685 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -408,6 +408,7 @@ our $Lval = qr{$Ident(?:$Member)*}; our $Int_type = qr{(?i)llu|ull|ll|lu|ul|l|u}; our $Binary = qr{(?i)0b[01]+$Int_type?}; our $Hex = qr{(?i)0x[0-9a-f]+$Int_type?}; +our $Hex_byte = qr{(?i)0x[0-9a-f]{1,2}}; our $Int = qr{[0-9]+$Int_type?}; our $Octal = qr{0[0-7]+$Int_type?}; our $String = qr{"[X\t]*"}; @@ -6858,6 +6859,18 @@ sub process { WARN("DUPLICATED_SYSCTL_CONST", "duplicated sysctl range checking value '$1', consider using the shared one in include/linux/sysctl.h\n" . $herecurr); } + +# document which binutils version supports the actual insn mnemonic so that the naked opcode bytes can be replaced. +# x86-only. Upper limit is rather arbitrary (max insn length on x86) but imposed so as to avoid perl aborts. + if ($realfile =~ m@^arch/x86/@ && + $rawline =~ /\s*\.byte\s+(?:$Hex_byte[,\s]*){1,15}/) { + + my $comment = ctx_locate_comment($file ? 0 : $first_line, $linenr); + if ($comment !~ /binutils (?:version )*[0-9.]+/ms) { + WARN("MISSING_BINUTILS_VERSION", + "Please consider documenting which binutils version supports these .byte-spelled insn opcodes by adding \"binutils version <num>\" in a comment above them.\n" . $herecurr); + } + } } # If we have no input at all, then there is nothing to report on -- 2.21.0 -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette
