From: Ben Hutchings <ben.hutchings@codethink.co.uk>
To: Arnd Bergmann <arnd@arndb.de>,
y2038@lists.linaro.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Bamvor Jian Zhang <bamv2005@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: Re: [Y2038] [PATCH 6/8] lp: fix sparc64 LPSETTIMEOUT ioctl
Date: Wed, 20 Nov 2019 19:27:27 +0000 [thread overview]
Message-ID: <41baf20a190039443cb2b82aea0c2a8ec872cfed.camel@codethink.co.uk> (raw)
In-Reply-To: <20191108203435.112759-7-arnd@arndb.de>
On Fri, 2019-11-08 at 21:34 +0100, Arnd Bergmann wrote:
> The layout of struct timeval is different on sparc64 from
> anything else, and the patch I did long ago failed to take
> this into account.
>
> Change it now to handle sparc64 user space correctly again.
>
> Quite likely nobody cares about parallel ports on sparc64,
> but there is no reason not to fix it.
>
> Cc: stable@vger.kernel.org
> Fixes: 9a450484089d ("lp: support 64-bit time_t user space")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/char/lp.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/char/lp.c b/drivers/char/lp.c
> index 7c9269e3477a..bd95aba1f9fe 100644
> --- a/drivers/char/lp.c
> +++ b/drivers/char/lp.c
> @@ -713,6 +713,10 @@ static int lp_set_timeout64(unsigned int minor, void __user *arg)
> if (copy_from_user(karg, arg, sizeof(karg)))
> return -EFAULT;
>
> + /* sparc64 suseconds_t is 32-bit only */
> + if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
> + karg[1] >>= 32;
> +
> return lp_set_timeout(minor, karg[0], karg[1]);
> }
>
It seems like it would make way more sense to use __kernel_old_timeval.
Then you don't have to explicitly handle the sparc64 oddity.
As it is, this still over-reads from user-space which might result in a
spurious -EFAULT.
Ben.
--
Ben Hutchings, Software Developer Codethink Ltd
https://www.codethink.co.uk/ Dale House, 35 Dale Street
Manchester, M1 2HF, United Kingdom
next prev parent reply other threads:[~2019-11-20 19:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191108203435.112759-1-arnd@arndb.de>
2019-11-08 20:34 ` [PATCH 1/8] y2038: timex: remove incorrect time_t truncation Arnd Bergmann
2019-11-10 20:44 ` Deepa Dinamani
2019-11-12 7:16 ` [tip: timers/urgent] ntp/y2038: Remove " tip-bot2 for Arnd Bergmann
2019-11-08 20:34 ` [PATCH 6/8] lp: fix sparc64 LPSETTIMEOUT ioctl Arnd Bergmann
2019-11-20 19:27 ` Ben Hutchings [this message]
2019-11-20 19:46 ` [Y2038] " Arnd Bergmann
2019-11-20 22:10 ` Ben Hutchings
2019-11-21 14:04 ` Arnd Bergmann
2019-11-21 16:00 ` Ben Hutchings
2019-11-08 20:34 ` [PATCH 7/8] ppdev: fix PPGETTIME/PPSETTIME ioctls Arnd Bergmann
2019-11-20 19:29 ` [Y2038] " Ben Hutchings
2019-11-21 14:06 ` Arnd Bergmann
2019-11-08 20:34 ` [PATCH 8/8] Input: input_event: fix struct padding on sparc64 Arnd Bergmann
2019-11-11 18:28 ` Dmitry Torokhov
2019-11-11 19:18 ` Arnd Bergmann
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