[PATCH 6/8] lp: fix sparc64 LPSETTIMEOUT ioctl

From: Arnd Bergmann <arnd@arndb.de>
To: y2038@lists.linaro.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	stable@vger.kernel.org, Bamvor Jian Zhang <bamv2005@gmail.com>,
	Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 6/8] lp: fix sparc64 LPSETTIMEOUT ioctl
Date: Fri,  8 Nov 2019 21:34:29 +0100	[thread overview]
Message-ID: <20191108203435.112759-7-arnd@arndb.de> (raw)
In-Reply-To: <20191108203435.112759-1-arnd@arndb.de>

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]);
 }
 
-- 
2.20.0

