On Sat, Jul 06, 2019 at 10:17:18PM +0900, Masahiro Yamada wrote:
> On Sun, Jun 23, 2019 at 4:29 PM Kirill Smelkov <[email protected]> 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/[email protected]/
> >
> > https://lore.kernel.org/linux-pci/[email protected]/
> >
> > https://lore.kernel.org/linux-pci/[email protected]/
> >
> > 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 <[email protected]>
> > Cc: Logan Gunthorpe <[email protected]>
> > Cc: Sebastian Andrzej Siewior <[email protected]>
> > Cc: Bjorn Helgaas <[email protected]>
> > Signed-off-by: Kirill Smelkov <[email protected]>
> > ---
>
> Applied to linux-kbuild. Thanks.
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
> > [email protected]
> > https://systeme.lip6.fr/mailman/listinfo/cocci
>
>
>
> --
> Best Regards
> Masahiro Yamada
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