From 0c4ab18fc33bba70299f51fac83e32397cf9a04b Mon Sep 17 00:00:00 2001 From: Kirill Smelkov Date: Sun, 23 Jun 2019 07:28:53 +0000 Subject: [PATCH] coccinelle: api/stream_open: treat all wait_.*() calls as blocking 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: _fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. while after this patch it will report: ERROR: _fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. Signed-off-by: Kirill Smelkov Acked-by: Julia Lawall Signed-off-by: Masahiro Yamada --- 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 }