Commit 8716de38 authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds
Browse files

checkpatch: add test for positional misuse of section specifiers like __initdata 

As discussed recently on the arm [1] and lm-sensors [2] lists, it is
possible to use section markers on variables in a way which gcc doesn't
understand (or at least not the way the developer intended):

static struct __initdata samsung_pll_clock exynos4_plls[nr_plls] = {

does NOT put exynos4_plls in the .initdata section.  The __initdata marker
can be virtually anywhere on the line, EXCEPT right after "struct".  The
preferred location is before the "=" sign if there is one, or before the
trailing ";" otherwise.

[1] http://permalink.gmane.org/gmane.linux.ports.arm.kernel/258149
[2] http://lists.lm-sensors.org/pipermail/lm-sensors/2013-August/039836.html

So, update checkpatch to find these misuses and report an error when it's
immediately after struct or union, and a warning when it's otherwise not
immediately before the ; or =.

A similar patch was suggested by Andi Kleen
https://lkml.org/lkml/2013/8/5/648



Signed-off-by: default avatarJoe Perches <joe@perches.com>
Suggested-by: default avatarJean Delvare <khali@linux-fr.org>
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 58cb3cf6

scripts/checkpatch.pl

+46 −1
Original line number Diff line number Diff line
@@ -242,6 +242,8 @@ our $Sparse = qr{ 
			__rcu

		}x;



our $InitAttribute = qr{__(?:mem|cpu|dev|net_|)(?:initdata|initconst|init\b)};



# Notes to $Attribute:

# We need \b after 'init' otherwise 'initconst' will cause a false positive in a check

our $Attribute	= qr{
@@ -262,7 +264,7 @@ our $Attribute = qr{ 
			__deprecated|

			__read_mostly|

			__kprobes|

			__(?:mem|cpu|dev|)(?:initdata|initconst|init\b)|

			$InitAttribute|

			____cacheline_aligned|

			____cacheline_aligned_in_smp|

			____cacheline_internodealigned_in_smp|
@@ -292,6 +294,7 @@ our $Operators = qr{ 
		  }x;



our $NonptrType;

our $NonptrTypeWithAttr;

our $Type;

our $Declare;
@@ -354,6 +357,12 @@ our @typeList = ( 
	qr{${Ident}_handler},

	qr{${Ident}_handler_fn},

);

our @typeListWithAttr = (

	@typeList,

	qr{struct\s+$InitAttribute\s+$Ident},

	qr{union\s+$InitAttribute\s+$Ident},

);



our @modifierList = (

	qr{fastcall},

);
@@ -367,6 +376,7 @@ our $allowed_asm_includes = qr{(?x: 
sub build_types {

	my $mods = "(?x:  \n" . join("|\n  ", @modifierList) . "\n)";

	my $all = "(?x:  \n" . join("|\n  ", @typeList) . "\n)";

	my $allWithAttr = "(?x:  \n" . join("|\n  ", @typeListWithAttr) . "\n)";

	$Modifier	= qr{(?:$Attribute|$Sparse|$mods)};

	$NonptrType	= qr{

			(?:$Modifier\s+|const\s+)*
@@ -377,6 +387,15 @@ sub build_types { 
			)

			(?:\s+$Modifier|\s+const)*

		  }x;

	$NonptrTypeWithAttr	= qr{

			(?:$Modifier\s+|const\s+)*

			(?:

				(?:typeof|__typeof__)\s*\([^\)]*\)|

				(?:$typeTypedefs\b)|

				(?:${allWithAttr}\b)

			)

			(?:\s+$Modifier|\s+const)*

		  }x;

	$Type	= qr{

			$NonptrType

			(?:(?:\s|\*|\[\])+\s*const|(?:\s|\*|\[\])+|(?:\s*\[\s*\])+)?
@@ -3706,6 +3725,32 @@ sub process { 
			}

		}



sub string_find_replace {

	my ($string, $find, $replace) = @_;



	$string =~ s/$find/$replace/g;



	return $string;

}



# check for bad placement of section $InitAttribute (e.g.: __initdata)

		if ($line =~ /(\b$InitAttribute\b)/) {

			my $attr = $1;

			if ($line =~ /^\+\s*static\s+(?:const\s+)?(?:$attr\s+)?($NonptrTypeWithAttr)\s+(?:$attr\s+)?($Ident(?:\[[^]]*\])?)\s*[=;]/) {

				my $ptr = $1;

				my $var = $2;

				if ((($ptr =~ /\b(union|struct)\s+$attr\b/ &&

				      ERROR("MISPLACED_INIT",

					    "$attr should be placed after $var\n" . $herecurr)) ||

				     ($ptr !~ /\b(union|struct)\s+$attr\b/ &&

				      WARN("MISPLACED_INIT",

					   "$attr should be placed after $var\n" . $herecurr))) &&

				    $fix) {

					$fixed[$linenr - 1] =~ s/(\bstatic\s+(?:const\s+)?)(?:$attr\s+)?($NonptrTypeWithAttr)\s+(?:$attr\s+)?($Ident(?:\[[^]]*\])?)\s*([=;])\s*/"$1" . trim(string_find_replace($2, "\\s*$attr\\s*", " ")) . " " . trim(string_find_replace($3, "\\s*$attr\\s*", "")) . " $attr" . ("$4" eq ";" ? ";" : " = ")/e;

				}

			}

		}



# prefer usleep_range over udelay

		if ($line =~ /\budelay\s*\(\s*(\d+)\s*\)/) {

			# ignore udelay's < 10, however

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