+ checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch added to -mm tree

+ checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch added to -mm tree

[akpm]

The patch titled
     Subject: checkpatch: do not apply "initialise globals to 0" check to BPF progs
has been added to the -mm tree.  Its filename is
     checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Song Liu <songliubraving@fb.com>
Subject: checkpatch: do not apply "initialise globals to 0" check to BPF progs

BPF programs explicitly initialise global variables to 0 to make sure
clang (v10 or older) do not put the variables in the common section.  Skip
"initialise globals to 0" check for BPF programs to elimiate error
messages like:

    ERROR: do not initialise globals to 0
    #19: FILE: samples/bpf/tracex1_kern.c:21:

Link: https://lkml.kernel.org/r/20210209211954.490077-1-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 scripts/checkpatch.pl |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/scripts/checkpatch.pl~checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs
+++ a/scripts/checkpatch.pl
@@ -2453,6 +2453,15 @@ sub get_raw_comment {
 	return $comment;
 }
 
+sub exclude_global_initialisers {
+	my ($realfile) = @_;
+
+	# Do not check for BPF programs (tools/testing/selftests/bpf/progs/*.c, samples/bpf/*_kern.c, *.bpf.c).
+	return $realfile =~ m@^tools/testing/selftests/bpf/progs/.*\.c$@ ||
+		$realfile =~ m@^samples/bpf/.*_kern\.c$@ ||
+		$realfile =~ m@/bpf/.*\.bpf\.c$@;
+}
+
 sub process {
 	my $filename = shift;
 
@@ -4360,7 +4369,8 @@ sub process {
 		}
 
 # check for global initialisers.
-		if ($line =~ /^\+$Type\s*$Ident(?:\s+$Modifier)*\s*=\s*($zero_initializer)\s*;/) {
+		if ($line =~ /^\+$Type\s*$Ident(?:\s+$Modifier)*\s*=\s*($zero_initializer)\s*;/ &&
+		    !exclude_global_initialisers($realfile)) {
 			if (ERROR("GLOBAL_INITIALISERS",
 				  "do not initialise globals to $1\n" . $herecurr) &&
 			    $fix) {
_

Patches currently in -mm which might be from songliubraving@fb.com are

checkpatch-do-not-apply-initialise-globals-to-0-check-to-bpf-progs.patch