From: Aditya Srivastava <yashsri421@xxxxxxxxx> Subject: checkpatch: add warning for avoiding .L prefix symbols in assembly files objtool requires that all code must be contained in an ELF symbol. Symbol names that have a '.L' prefix do not emit symbol table entries, as they have special meaning for the assembler. '.L' prefixed symbols can be used within a code region, but should be avoided for denoting a range of code via 'SYM_*_START/END' annotations. Add a new check to emit a warning on finding the usage of '.L' symbols for '.S' files, if it denotes range of code via SYM_*_START/END annotation pair. Link: https://lkml.kernel.org/r/20210123190459.9701-1-yashsri421@xxxxxxxxx Link: https://lore.kernel.org/lkml/20210112210154.GI4646@xxxxxxxxxxxxx Signed-off-by: Aditya Srivastava <yashsri421@xxxxxxxxx> Suggested-by: Mark Brown <broonie@xxxxxxxxxx> Acked-by: Joe Perches <joe@xxxxxxxxxxx> Acked-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Aditya Srivastava <yashsri421@xxxxxxxxx> Cc: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx> Cc: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- scripts/checkpatch.pl | 7 +++++++ 1 file changed, 7 insertions(+) --- a/scripts/checkpatch.pl~checkpatch-add-warning-for-avoiding-l-prefix-symbols-in-assembly-files +++ a/scripts/checkpatch.pl @@ -3599,6 +3599,13 @@ sub process { } } +# check for .L prefix local symbols in .S files + if ($realfile =~ /\.S$/ && + $line =~ /^\+\s*(?:[A-Z]+_)?SYM_[A-Z]+_(?:START|END)(?:_[A-Z_]+)?\s*\(\s*\.L/) { + WARN("AVOID_L_PREFIX", + "Avoid using '.L' prefixed local symbol names for denoting a range of code via 'SYM_*_START/END' annotations; see Documentation/asm-annotations.rst\n" . $herecurr); + } + # check we are in a valid source file C or perl if not then ignore this hunk next if ($realfile !~ /\.(h|c|pl|dtsi|dts)$/); _
