Re: [Linux-kernel-mentees] [PATCH v3] checkpatch: add warning for avoiding .L prefix symbols in assembly files
From: Joe Perches <joe@perches.com>
Date: 2021-01-23 21:02:51
Also in:
lkml
On Sun, 2021-01-24 at 00:34 +0530, Aditya Srivastava wrote:
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. Suggested-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/lkml/20210112210154.GI4646@sirena.org.uk (local) Signed-off-by: Aditya Srivastava <redacted>
Acked-by: Joe Perches <joe@perches.com>
quoted hunk ↗ jump to hunk
--- * Applies perfectly on next-20210122 Changes in v3: - Modify regex for SYM_*_START/END pair - remove check for arch/x86/entry/* and arch/x86/lib/* - change 'Link:' in commit message to lkml - Modify commit description accordingly Changes in v2: - Reduce the check to only SYM_*_START/END lines - Reduce the check for only .S files in arch/x86/entry/* and arch/x86/lib/* as suggested by Josh and Nick - Modify commit message scripts/checkpatch.pl | 7 +++++++ 1 file changed, 7 insertions(+)diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 7030c4d6d126..4a03326c87b6 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl@@ -3590,6 +3590,13 @@ 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)$/);
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