Messages in this thread | | | From | Masahiro Yamada <> | Date | Sat, 6 Jul 2019 22:17:18 +0900 | Subject | Re: [Cocci] [PATCH 1/2] coccinelle: api/stream_open: treat all wait_.*() calls as blocking |
| |
On Sun, Jun 23, 2019 at 4:29 PM Kirill Smelkov <kirr@nexedi.com> wrote: > > Previously steam_open.cocci was treating only wait_event_.* - e.g. > wait_event_interruptible - as a blocking operation. However e.g. > wait_for_completion_interruptible is also blocking, and so from this > point of view it would be more logical to treat all wait_.* as a > blocking point. > > The logic of this change actually came up for real when > drivers/pci/switch/switchtec.c changed from using > wait_event_interruptible to wait_for_completion_interruptible: > > https://lore.kernel.org/linux-pci/20190413170056.GA11293@deco.navytux.spb.ru/ > https://lore.kernel.org/linux-pci/20190415145456.GA15280@deco.navytux.spb.ru/ > https://lore.kernel.org/linux-pci/20190415154102.GB17661@deco.navytux.spb.ru/ > > For a driver that uses nonseekable_open with read/write having stream > semantic and read also calling e.g. wait_for_completion_interruptible, > running stream_open.cocci before this patch would produce: > > WARNING: <driver>_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. > > while after this patch it will report: > > ERROR: <driver>_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. > > Cc: Julia Lawall <Julia.Lawall@lip6.fr> > Cc: Logan Gunthorpe <logang@deltatee.com> > Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > Cc: Bjorn Helgaas <helgaas@kernel.org> > Signed-off-by: Kirill Smelkov <kirr@nexedi.com> > ---
Applied to linux-kbuild. Thanks.
> scripts/coccinelle/api/stream_open.cocci | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/scripts/coccinelle/api/stream_open.cocci b/scripts/coccinelle/api/stream_open.cocci > index 350145da7669..12ce18fa6b74 100644 > --- a/scripts/coccinelle/api/stream_open.cocci > +++ b/scripts/coccinelle/api/stream_open.cocci > @@ -35,11 +35,11 @@ type loff_t; > // a function that blocks > @ blocks @ > identifier block_f; > -identifier wait_event =~ "^wait_event_.*"; > +identifier wait =~ "^wait_.*"; > @@ > block_f(...) { > ... when exists > - wait_event(...) > + wait(...) > ... when exists > } > > @@ -49,12 +49,12 @@ identifier wait_event =~ "^wait_event_.*"; > // XXX currently reader_blocks supports only direct and 1-level indirect cases. > @ reader_blocks_direct @ > identifier stream_reader.readstream; > -identifier wait_event =~ "^wait_event_.*"; > +identifier wait =~ "^wait_.*"; > @@ > readstream(...) > { > ... when exists > - wait_event(...) > + wait(...) > ... when exists > } > > -- > 2.20.1 > _______________________________________________ > Cocci mailing list > Cocci@systeme.lip6.fr > https://systeme.lip6.fr/mailman/listinfo/cocci
-- Best Regards Masahiro Yamada
| |