Re: [PATCH] random: Forbid llseek on random chardev

From: Matt Mackall
Date: Sat Apr 10 2010 - 12:26:01 EST


On Sat, 2010-04-10 at 16:17 +0200, Frederic Weisbecker wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Seeking on /dev/random and /dev/urandom is pointless.

It is indeed pointless, though that doesn't mean no one does it.
Forbidding a no-op seems a rather unfriendly way to fix this.

> Using generic_file_llseek means we no longer need to
> take the BKL if anyone tries to seek on these.

Comment doesn't match the patch?

> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Matt Mackall <mpm@xxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> ---
> drivers/char/random.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 2fd3d39..513c685 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -1169,6 +1169,7 @@ const struct file_operations random_fops = {
> .poll = random_poll,
> .unlocked_ioctl = random_ioctl,
> .fasync = random_fasync,
> + .open = nonseekable_open,
> };
>
> const struct file_operations urandom_fops = {
> @@ -1176,6 +1177,7 @@ const struct file_operations urandom_fops = {
> .write = random_write,
> .unlocked_ioctl = random_ioctl,
> .fasync = random_fasync,
> + .open = nonseekable_open,
> };
>
> /***************************************************************



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