diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2010-06-02 14:28:52 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-05 15:01:04 +0200 |
| commit | 613655fa39ff6957754fa8ceb8559980920eb8ee (patch) | |
| tree | ad19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/nvram.c | |
| parent | 609146fdb319cebce93be550938ab852f7bade90 (diff) | |
| download | kernel_samsung_smdk4412-613655fa39ff6957754fa8ceb8559980920eb8ee.zip kernel_samsung_smdk4412-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.gz kernel_samsung_smdk4412-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.bz2 | |
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/nvram.c')
| -rw-r--r-- | drivers/char/nvram.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c index 66d2917..166f1e7 100644 --- a/drivers/char/nvram.c +++ b/drivers/char/nvram.c @@ -109,10 +109,11 @@ #include <linux/spinlock.h> #include <linux/io.h> #include <linux/uaccess.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <asm/system.h> +static DEFINE_MUTEX(nvram_mutex); static DEFINE_SPINLOCK(nvram_state_lock); static int nvram_open_cnt; /* #times opened */ static int nvram_open_mode; /* special open modes */ @@ -308,7 +309,7 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, if (!capable(CAP_SYS_ADMIN)) return -EACCES; - lock_kernel(); + mutex_lock(&nvram_mutex); spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) @@ -316,7 +317,7 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); - unlock_kernel(); + mutex_unlock(&nvram_mutex); return 0; case NVRAM_SETCKS: @@ -325,11 +326,11 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, if (!capable(CAP_SYS_ADMIN)) return -EACCES; - lock_kernel(); + mutex_lock(&nvram_mutex); spin_lock_irq(&rtc_lock); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); - unlock_kernel(); + mutex_unlock(&nvram_mutex); return 0; default: |