On Fri, 2019-08-09 at 15:21 -0700, Nick Desaulniers wrote: > Hi Joe, > While debugging: > https://github.com/ClangBuiltLinux/linux/issues/619 > we found a bunch of places where __section is not used but could be, > and uses a string literal when it probably should not be. > > Just a thought that maybe checkpatch.pl could warn if > `__attribute__((section` appeared in the added diff, and suggest > __section? Then further warn to not use `""` for the section name?
Hmm, that makes me wonder about the existing __section uses _with_ a quote are actually in the proper sections. $ git grep -n -P '\b__section\s*\(\s*"' arch/arm64/kernel/smp_spin_table.c:22:volatile unsigned long __section(".mmuoff.data.read") arch/s390/boot/startup.c:49:static struct diag210 _diag210_tmp_dma __section(".dma.data"); include/linux/compiler.h:27: __section("_ftrace_annotated_branch") \ include/linux/compiler.h:63: __section("_ftrace_branch") \ include/linux/compiler.h:121:#define __annotate_jump_table __section(".rodata..c_jump_table") include/linux/compiler.h:158: __section("___kentry" "+" #sym ) \ include/linux/compiler.h:301: static void * __section(".discard.addressable") __used \ include/linux/export.h:107: static int __ksym_marker_##sym[0] __section(".discard.ksym") __used include/linux/srcutree.h:127: __section("___srcu_struct_ptrs") = &name Maybe there should also be a __section("<foo>") test too. Anyway, how about: --- scripts/checkpatch.pl | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 1cdacb4fd207..8e6693ca772c 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -5901,6 +5901,15 @@ sub process { "__aligned(size) is preferred over __attribute__((aligned(size)))\n" . $herecurr); } +# Check for __attribute__ section, prefer __section (without quotes) + if ($realfile !~ m@\binclude/uapi/@ && + $line =~ /\b__attribute__\s*\(\s*\(.*_*section_*\s*\(\s*("[^"]*")/) { + my $old = substr($rawline, $-[1], $+[1] - $-[1]); + my $new = substr($old, 1, -1); + WARN("PREFER_SECTION", + "__section($new) is preferred over __attribute__((section($old)))\n" . $herecurr); + } + # Check for __attribute__ format(printf, prefer __printf if ($realfile !~ m@\binclude/uapi/@ && $line =~ /\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf/) {