From d21c95c569c462da20d491b75d0a45bd70ddc1bf Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Fri, 16 May 2008 13:40:30 -0600 Subject: Add "no BKL needed" comments to several drivers This documents the fact that somebody looked at the relevant open() functions and concluded that, due to their trivial nature, no locking was needed. Signed-off-by: Jonathan Corbet --- drivers/char/dtlk.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/char/dtlk.c') diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c index abde6ddefe6..433388c6023 100644 --- a/drivers/char/dtlk.c +++ b/drivers/char/dtlk.c @@ -288,6 +288,8 @@ static int dtlk_ioctl(struct inode *inode, } } +/* No BKL needed here; "dtlk_busy" is the only global resource, + and it is not ever set by anybody (test is broken) */ static int dtlk_open(struct inode *inode, struct file *file) { TRACE_TEXT("(dtlk_open"); -- cgit v1.2.3 From f2b9857eee17797541b845782ade4d7a9d50f843 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 18 May 2008 15:32:43 -0600 Subject: Add a bunch of cycle_kernel_lock() calls All of the open() functions which don't need the BKL on their face may still depend on its acquisition to serialize opens against driver initialization. So make those functions acquire then release the BKL to be on the safe side. Signed-off-by: Jonathan Corbet --- drivers/char/dtlk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/char/dtlk.c') diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c index 433388c6023..6b900b297cc 100644 --- a/drivers/char/dtlk.c +++ b/drivers/char/dtlk.c @@ -56,6 +56,7 @@ #include /* for -EBUSY */ #include /* for request_region */ #include /* for loops_per_jiffy */ +#include /* cycle_kernel_lock() */ #include /* for inb_p, outb_p, inb, outb, etc. */ #include /* for get_user, etc. */ #include /* for wait_queue */ @@ -288,12 +289,12 @@ static int dtlk_ioctl(struct inode *inode, } } -/* No BKL needed here; "dtlk_busy" is the only global resource, - and it is not ever set by anybody (test is broken) */ +/* Note that nobody ever sets dtlk_busy... */ static int dtlk_open(struct inode *inode, struct file *file) { TRACE_TEXT("(dtlk_open"); + cycle_kernel_lock(); nonseekable_open(inode, file); switch (iminor(inode)) { case DTLK_MINOR: -- cgit v1.2.3