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authorArnd Bergmann <arnd@arndb.de>2010-06-02 14:28:52 +0200
committerArnd Bergmann <arnd@arndb.de>2010-10-05 15:01:04 +0200
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/apm-emulation.c
parent609146fdb319cebce93be550938ab852f7bade90 (diff)
drivers: autoconvert trivial BKL users to private mutex
All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. These drivers do not seem to be under active maintainance from my brief investigation. Apologies to those maintainers that I have missed. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/char/apm-emulation.c')
-rw-r--r--drivers/char/apm-emulation.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/char/apm-emulation.c b/drivers/char/apm-emulation.c
index 033e1505fca..6a420baea26 100644
--- a/drivers/char/apm-emulation.c
+++ b/drivers/char/apm-emulation.c
@@ -13,7 +13,7 @@
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>
@@ -126,6 +126,7 @@ struct apm_user {
/*
* Local variables
*/
+static DEFINE_MUTEX(apm_mutex);
static atomic_t suspend_acks_pending = ATOMIC_INIT(0);
static atomic_t userspace_notification_inhibit = ATOMIC_INIT(0);
static int apm_disabled;
@@ -274,7 +275,7 @@ apm_ioctl(struct file *filp, u_int cmd, u_long arg)
if (!as->suser || !as->writer)
return -EPERM;
- lock_kernel();
+ mutex_lock(&apm_mutex);
switch (cmd) {
case APM_IOC_SUSPEND:
mutex_lock(&state_lock);
@@ -335,7 +336,7 @@ apm_ioctl(struct file *filp, u_int cmd, u_long arg)
mutex_unlock(&state_lock);
break;
}
- unlock_kernel();
+ mutex_unlock(&apm_mutex);
return err;
}
@@ -370,7 +371,7 @@ static int apm_open(struct inode * inode, struct file * filp)
{
struct apm_user *as;
- lock_kernel();
+ mutex_lock(&apm_mutex);
as = kzalloc(sizeof(*as), GFP_KERNEL);
if (as) {
/*
@@ -390,7 +391,7 @@ static int apm_open(struct inode * inode, struct file * filp)
filp->private_data = as;
}
- unlock_kernel();
+ mutex_unlock(&apm_mutex);
return as ? 0 : -ENOMEM;
}