* [PATCH v2 0/3] checkpatch: handling of memory barriers
@ 2016-01-10 11:56 Michael S. Tsirkin
2016-01-10 11:56 ` [PATCH v2 1/3] checkpatch.pl: add missing " Michael S. Tsirkin
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 11:56 UTC (permalink / raw)
To: linux-kernel
Cc: Andy Whitcroft, Joe Perches, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
As part of memory barrier cleanup, this patchset
extends checkpatch to make it easier to stop
incorrect memory barrier usage.
This applies on top of my series
arch: barrier cleanup + barriers for virt
and will be included in the next version of the series.
Changes from v2:
catch optional\s* before () in barriers
rewrite using qr{} instead of map
Michael S. Tsirkin (3):
checkpatch.pl: add missing memory barriers
checkpatch: check for __smp outside barrier.h
checkpatch: add virt barriers
scripts/checkpatch.pl | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
--
MST
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v2 1/3] checkpatch.pl: add missing memory barriers
2016-01-10 11:56 [PATCH v2 0/3] checkpatch: handling of memory barriers Michael S. Tsirkin
@ 2016-01-10 11:56 ` Michael S. Tsirkin
2016-01-10 15:07 ` Joe Perches
2016-01-10 11:57 ` [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h Michael S. Tsirkin
2016-01-10 11:57 ` [PATCH v2 3/3] checkpatch: add virt barriers Michael S. Tsirkin
2 siblings, 1 reply; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 11:56 UTC (permalink / raw)
To: linux-kernel
Cc: Andy Whitcroft, Joe Perches, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
SMP-only barriers were missing in checkpatch.pl
Refactor code slightly to make adding more variants easier.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
scripts/checkpatch.pl | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2b3c228..97b8b62 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5116,7 +5116,25 @@ sub process {
}
}
# check for memory barriers without a comment.
- if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
+
+ my $barriers = qr{
+ mb|
+ rmb|
+ wmb|
+ read_barrier_depends
+ }x;
+ my $smp_barriers = qr{
+ store_release|
+ load_acquire|
+ store_mb|
+ ($barriers)
+ }x;
+ my $all_barriers = qr{
+ $barriers|
+ smp_($smp_barriers)
+ }x;
+
+ if ($line =~ /\b($all_barriers)\s*\(/) {
if (!ctx_has_comment($first_line, $linenr)) {
WARN("MEMORY_BARRIER",
"memory barrier without comment\n" . $herecurr);
--
MST
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h
2016-01-10 11:56 [PATCH v2 0/3] checkpatch: handling of memory barriers Michael S. Tsirkin
2016-01-10 11:56 ` [PATCH v2 1/3] checkpatch.pl: add missing " Michael S. Tsirkin
@ 2016-01-10 11:57 ` Michael S. Tsirkin
2016-01-10 15:08 ` Joe Perches
2016-01-10 11:57 ` [PATCH v2 3/3] checkpatch: add virt barriers Michael S. Tsirkin
2 siblings, 1 reply; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 11:57 UTC (permalink / raw)
To: linux-kernel
Cc: Andy Whitcroft, Joe Perches, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
Introduction of __smp barriers cleans up a bunch of duplicate code, but
it gives people an additional handle onto a "new" set of barriers - just
because they're prefixed with __* unfortunately doesn't stop anyone from
using it (as happened with other arch stuff before.)
Add a checkpatch test so it will trigger a warning.
Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
scripts/checkpatch.pl | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 97b8b62..a96adcb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5141,6 +5141,16 @@ sub process {
}
}
+ my $underscore_smp_barriers = qr{__smp_($smp_barriers)}x;
+
+ if ($realfile !~ m@^include/asm-generic/@ &&
+ $realfile !~ m@/barrier\.h$@ &&
+ $line =~ m/\b($underscore_smp_barriers)\s*\(/ &&
+ $line !~ m/^.\s*\#\s*define\s+($underscore_smp_barriers)\s*\(/) {
+ WARN("MEMORY_BARRIER",
+ "__smp memory barriers shouldn't be used outside barrier.h and asm-generic\n" . $herecurr);
+ }
+
# check for waitqueue_active without a comment.
if ($line =~ /\bwaitqueue_active\s*\(/) {
if (!ctx_has_comment($first_line, $linenr)) {
--
MST
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 3/3] checkpatch: add virt barriers
2016-01-10 11:56 [PATCH v2 0/3] checkpatch: handling of memory barriers Michael S. Tsirkin
2016-01-10 11:56 ` [PATCH v2 1/3] checkpatch.pl: add missing " Michael S. Tsirkin
2016-01-10 11:57 ` [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h Michael S. Tsirkin
@ 2016-01-10 11:57 ` Michael S. Tsirkin
2 siblings, 0 replies; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 11:57 UTC (permalink / raw)
To: linux-kernel
Cc: Andy Whitcroft, Joe Perches, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
Add virt_ barriers to list of barriers to check for
presence of a comment.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
scripts/checkpatch.pl | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index a96adcb..5ca272b 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5131,7 +5131,8 @@ sub process {
}x;
my $all_barriers = qr{
$barriers|
- smp_($smp_barriers)
+ smp_($smp_barriers)|
+ virt_($smp_barriers)
}x;
if ($line =~ /\b($all_barriers)\s*\(/) {
--
MST
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2 1/3] checkpatch.pl: add missing memory barriers
2016-01-10 11:56 ` [PATCH v2 1/3] checkpatch.pl: add missing " Michael S. Tsirkin
@ 2016-01-10 15:07 ` Joe Perches
2016-01-10 15:17 ` Joe Perches
2016-01-10 19:13 ` Michael S. Tsirkin
0 siblings, 2 replies; 9+ messages in thread
From: Joe Perches @ 2016-01-10 15:07 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: Andy Whitcroft, Peter Zijlstra, Arnd Bergmann, linux-arch,
Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
On Sun, 2016-01-10 at 13:56 +0200, Michael S. Tsirkin wrote:
> SMP-only barriers were missing in checkpatch.pl
>
> Refactor code slightly to make adding more variants easier.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -5116,7 +5116,25 @@ sub process {
> }
> }
> # check for memory barriers without a comment.
> - if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
> +
> + my $barriers = qr{
> + mb|
> + rmb|
> + wmb|
> + read_barrier_depends
> + }x;
> + my $smp_barriers = qr{
> + store_release|
> + load_acquire|
> + store_mb|
> + ($barriers)
> + }x;
If I use a variable called $smp_barriers, I'd expect
it to actually be the smp_barriers, not to have to
prefix it with smp_ before using it.
my $smp_barriers = qr{
smp_store_release|
smp_load_acquire|
smp_store_mb|
smp_read_barrier_depends
}x;
or
my $smp_barriers = qr{
smp_(?:store_release|load_acquire|store_mb|read_barrier_depends)
}x;
> + my $all_barriers = qr{
> + $barriers|
> + smp_($smp_barriers)
> + }x;
And this shouldn't have a capture group.
my $all_barriers = qr{
$barriers|
$smp_barriers
}x;
> +
> + if ($line =~ /\b($all_barriers)\s*\(/) {
This doesn't need the capture group either (?:all_barriers)
> if (!ctx_has_comment($first_line, $linenr))
> {
> WARN("MEMORY_BARRIER",
> "memory barrier without
> comment\n" . $herecurr);
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h
2016-01-10 11:57 ` [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h Michael S. Tsirkin
@ 2016-01-10 15:08 ` Joe Perches
0 siblings, 0 replies; 9+ messages in thread
From: Joe Perches @ 2016-01-10 15:08 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: Andy Whitcroft, Peter Zijlstra, Arnd Bergmann, linux-arch,
Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
On Sun, 2016-01-10 at 13:57 +0200, Michael S. Tsirkin wrote:
> Introduction of __smp barriers cleans up a bunch of duplicate code, but
> it gives people an additional handle onto a "new" set of barriers - just
> because they're prefixed with __* unfortunately doesn't stop anyone from
> using it (as happened with other arch stuff before.)
>
> Add a checkpatch test so it will trigger a warning.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -5141,6 +5141,16 @@ sub process {
> }
> }
>
> + my $underscore_smp_barriers = qr{__smp_($smp_barriers)}x;
another unnecessary capture group
> +
> + if ($realfile !~ m@^include/asm-generic/@ &&
> + $realfile !~ m@/barrier\.h$@ &&
> + $line =~ m/\b($underscore_smp_barriers)\s*\(/ &&
> + $line !~ m/^.\s*\#\s*define\s+($underscore_smp_barriers)\s*\(/) {
> + WARN("MEMORY_BARRIER",
> + "__smp memory barriers shouldn't be used outside barrier.h and asm-generic\n" . $herecurr);
> + }
> +
> # check for waitqueue_active without a comment.
> if ($line =~ /\bwaitqueue_active\s*\(/) {
> if (!ctx_has_comment($first_line, $linenr)) {
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2 1/3] checkpatch.pl: add missing memory barriers
2016-01-10 15:07 ` Joe Perches
@ 2016-01-10 15:17 ` Joe Perches
2016-01-10 19:29 ` Michael S. Tsirkin
2016-01-10 19:13 ` Michael S. Tsirkin
1 sibling, 1 reply; 9+ messages in thread
From: Joe Perches @ 2016-01-10 15:17 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: Andy Whitcroft, Peter Zijlstra, Arnd Bergmann, linux-arch,
Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
On Sun, 2016-01-10 at 07:07 -0800, Joe Perches wrote:
> On Sun, 2016-01-10 at 13:56 +0200, Michael S. Tsirkin wrote:
> > SMP-only barriers were missing in checkpatch.pl
> >
> > Refactor code slightly to make adding more variants easier.
> []
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> If I use a variable called $smp_barriers, I'd expect
> it to actually be the smp_barriers, not to have to
> prefix it with smp_ before using it.
>
> my $smp_barriers = qr{
> smp_store_release|
> smp_load_acquire|
> smp_store_mb|
> smp_read_barrier_depends
That's missing (?:barriers) too.
btw: shouldn't this also have
smp_mb__(?:before|after)_atomic
?
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2 1/3] checkpatch.pl: add missing memory barriers
2016-01-10 15:07 ` Joe Perches
2016-01-10 15:17 ` Joe Perches
@ 2016-01-10 19:13 ` Michael S. Tsirkin
1 sibling, 0 replies; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 19:13 UTC (permalink / raw)
To: Joe Perches
Cc: linux-kernel, Andy Whitcroft, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
On Sun, Jan 10, 2016 at 07:07:05AM -0800, Joe Perches wrote:
> On Sun, 2016-01-10 at 13:56 +0200, Michael S. Tsirkin wrote:
> > SMP-only barriers were missing in checkpatch.pl
> >
> > Refactor code slightly to make adding more variants easier.
> []
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > @@ -5116,7 +5116,25 @@ sub process {
> > }
> > }
> > # check for memory barriers without a comment.
> > - if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
> > +
> > + my $barriers = qr{
> > + mb|
> > + rmb|
> > + wmb|
> > + read_barrier_depends
> > + }x;
> > + my $smp_barriers = qr{
> > + store_release|
> > + load_acquire|
> > + store_mb|
> > + ($barriers)
> > + }x;
>
> If I use a variable called $smp_barriers, I'd expect
> it to actually be the smp_barriers, not to have to
> prefix it with smp_ before using it.
>
> my $smp_barriers = qr{
> smp_store_release|
> smp_load_acquire|
> smp_store_mb|
> smp_read_barrier_depends
> }x;
>
> or
>
> my $smp_barriers = qr{
> smp_(?:store_release|load_acquire|store_mb|read_barrier_depends)
> }x;
>
Yes but virt barriers (added in patch 3) are same things but prefixed
with virt_. So we need the stems without smp_ prefix. If smp_barriers is
too confusing we'll just need to give them some other name.
How about:
my $smp_barrier_stems
?
> > + my $all_barriers = qr{
> > + $barriers|
> > + smp_($smp_barriers)
> > + }x;
>
> And this shouldn't have a capture group.
>
> my $all_barriers = qr{
> $barriers|
> $smp_barriers
> }x;
> > +
> > + if ($line =~ /\b($all_barriers)\s*\(/) {
>
> This doesn't need the capture group either (?:all_barriers)
>
> > if (!ctx_has_comment($first_line, $linenr))
> > {
> > WARN("MEMORY_BARRIER",
> > "memory barrier without
> > comment\n" . $herecurr);
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2 1/3] checkpatch.pl: add missing memory barriers
2016-01-10 15:17 ` Joe Perches
@ 2016-01-10 19:29 ` Michael S. Tsirkin
0 siblings, 0 replies; 9+ messages in thread
From: Michael S. Tsirkin @ 2016-01-10 19:29 UTC (permalink / raw)
To: Joe Perches
Cc: linux-kernel, Andy Whitcroft, Peter Zijlstra, Arnd Bergmann,
linux-arch, Andrew Cooper, virtualization, Stefano Stabellini,
Thomas Gleixner, Ingo Molnar, H. Peter Anvin, David Miller,
linux-ia64, linuxppc-dev, linux-s390, sparclinux,
linux-arm-kernel, linux-metag, linux-mips, x86,
user-mode-linux-devel, adi-buildroot-devel, linux-sh,
linux-xtensa, xen-devel, Ingo Molnar, Tony Lindgren,
Andrey Konovalov, Russell King - ARM Linux
On Sun, Jan 10, 2016 at 07:17:31AM -0800, Joe Perches wrote:
> On Sun, 2016-01-10 at 07:07 -0800, Joe Perches wrote:
> > On Sun, 2016-01-10 at 13:56 +0200, Michael S. Tsirkin wrote:
> > > SMP-only barriers were missing in checkpatch.pl
> > >
> > > Refactor code slightly to make adding more variants easier.
> > []
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > If I use a variable called $smp_barriers, I'd expect
> > it to actually be the smp_barriers, not to have to
> > prefix it with smp_ before using it.
> >
> > my $smp_barriers = qr{
> > smp_store_release|
> > smp_load_acquire|
> > smp_store_mb|
> > smp_read_barrier_depends
>
> That's missing (?:barriers) too.
My version has it but need to add ?: to avoid
a capture group.
> btw: shouldn't this also have
> smp_mb__(?:before|after)_atomic
> ?
Good catch, included in the next version.
--
MST
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2016-01-10 19:29 UTC | newest]
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2016-01-10 11:56 [PATCH v2 0/3] checkpatch: handling of memory barriers Michael S. Tsirkin
2016-01-10 11:56 ` [PATCH v2 1/3] checkpatch.pl: add missing " Michael S. Tsirkin
2016-01-10 15:07 ` Joe Perches
2016-01-10 15:17 ` Joe Perches
2016-01-10 19:29 ` Michael S. Tsirkin
2016-01-10 19:13 ` Michael S. Tsirkin
2016-01-10 11:57 ` [PATCH v2 2/3] checkpatch: check for __smp outside barrier.h Michael S. Tsirkin
2016-01-10 15:08 ` Joe Perches
2016-01-10 11:57 ` [PATCH v2 3/3] checkpatch: add virt barriers Michael S. Tsirkin
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