On Sun, Jun 23, 2019 at 10:02:17AM +0200, Julia Lawall wrote: > On Sun, 23 Jun 2019, Kirill Smelkov wrote: > > On Sun, Jun 23, 2019 at 09:35:17AM +0200, Julia Lawall wrote: > > > On Sun, 23 Jun 2019, Kirill Smelkov 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. > > > > > > Are you really sure that every word that starts with wait_ in the Linux > > > kernel has the property you want? How many of them are there? Would it > > > be reasonable to put the names in the semantic patch explicitly? > > > > We are talking about function calls or macros here only. I think that > > by default every "wait.*()" has blocking semantic, and if there are > > something that does not block, it should be instead white-listed with > > the default still being treated as "all wait.*() blocks". > > > > Here are the list of wait functions & macros (if I read tags format > > correctly). They were generated with `grep -w d tags |grep '^wait'` and > > `grep -w f tags |grep '^wait'`. Offhand they all seem to be of blocking > > kind to me. > > OK, thanks for the list. > > julia
On Sun, Jun 23, 2019 at 10:01:52AM +0200, Julia Lawall wrote: > Acked-by: Julia Lawall <[email protected]> Julia, you are welcome. Thanks for ACK. Kirill _______________________________________________ Cocci mailing list [email protected] https://systeme.lip6.fr/mailman/listinfo/cocci
