From: Matt Mackall No locking actually needed. Signed-off-by: Matt Mackall Cc: Theodore Ts'o Signed-off-by: Andrew Morton --- drivers/char/random.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff -puN drivers/char/random.c~random-use-unlocked_ioctl drivers/char/random.c --- a/drivers/char/random.c~random-use-unlocked_ioctl +++ a/drivers/char/random.c @@ -1062,8 +1062,7 @@ static ssize_t random_write(struct file return (ssize_t)count; } -static int random_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) +static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) { int size, ent_count; int __user *p = (int __user *)arg; @@ -1071,8 +1070,8 @@ static int random_ioctl(struct inode *in switch (cmd) { case RNDGETENTCNT: - ent_count = input_pool.entropy_count; - if (put_user(ent_count, p)) + /* inherently racy, no point locking */ + if (put_user(input_pool.entropy_count, p)) return -EFAULT; return 0; case RNDADDTOENTCNT: @@ -1115,13 +1114,13 @@ const struct file_operations random_fops .read = random_read, .write = random_write, .poll = random_poll, - .ioctl = random_ioctl, + .unlocked_ioctl = random_ioctl, }; const struct file_operations urandom_fops = { .read = urandom_read, .write = random_write, - .ioctl = random_ioctl, + .unlocked_ioctl = random_ioctl, }; /*************************************************************** _