linux-kernel - [PATCH net-next 2/5] ppp: move simple ioctl compat handling out of fs_compat

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Date:   Wed, 29 Aug 2018 16:03:27 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     paulus@...ba.org, linux-ppp@...r.kernel.org, netdev@...r.kernel.org
Cc:     mitch@...oth.com, mostrows@...thlink.net, jchapman@...alix.com,
        xeb@...l.ru, davem@...emloft.net, viro@...iv.linux.org.uk,
        y2038@...ts.linaro.org, linux-kernel@...r.kernel.org,
        Arnd Bergmann <arnd@...db.de>,
        Guillaume Nault <g.nault@...halink.fr>
Subject: [PATCH net-next 2/5] ppp: move simple ioctl compat handling out of fs_compat_ioctl.c

There are multiple implementations of the PPP ioctl interface in the
kernel:

- drivers/net/ppp/ppp_generic.c implements a generic interface
  for the /dev/ppp chardev used by some subdrivers.
- drivers/net/ppp/pppox.c implements a socket based interface
  for pppoe, pptp and l2tp.
- drivers/isdn/i4l/isdn_ppp.c is for the i4l ISDN stack

All ioctl commands in the respective functions are compatible between
32-bit and 64-bit kernels, so we can simply mark the handlers themselves
as compatible and stop listing the commands individually.

Four commands (PPPIOCSCOMPRESS, PPPIOCSPASS, PPPIOCSACTIVE, and
PPPIOCGIDLE) are incompatible on the user level but have a translation
handler to make them compatible. I'm simplifying that compat handling
in separate patches.

The PPPIOCGUNIT and PPPIOCGCHAN ioctl commands are special, they are
implemented on various other file descriptors, so we have to keep them
listed as COMPATIBLE_IOCTL().

For the isdn_ppp code, additional ioctl commands are needed that have
never had working compat handling, so I'm leaving that part out: If
they are remaining users of i4l's ippp, they are not using compat
mode today, and are highly unlikely in the future before the last
ISDN network gets shut down. I4L has been deprecated since 2002.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/net/ppp/ppp_generic.c |  1 +
 drivers/net/ppp/pppoe.c       |  3 +++
 drivers/net/ppp/pptp.c        |  3 +++
 fs/compat_ioctl.c             | 31 -------------------------------
 net/l2tp/l2tp_ppp.c           |  3 +++
 5 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 02ad03a2fab7..41a6e9851a4a 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -899,6 +899,7 @@ static const struct file_operations ppp_device_fops = {
 	.write		= ppp_write,
 	.poll		= ppp_poll,
 	.unlocked_ioctl	= ppp_ioctl,
+	.compat_ioctl	= ppp_ioctl,
 	.open		= ppp_open,
 	.release	= ppp_release,
 	.llseek		= noop_llseek,
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index d1c3f9292c54..25174fa7a470 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -1120,6 +1120,9 @@ static const struct proto_ops pppoe_ops = {
 	.recvmsg	= pppoe_recvmsg,
 	.mmap		= sock_no_mmap,
 	.ioctl		= pppox_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= pppox_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppoe_proto = {
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 67ffe74747a1..3b5ab3f6745c 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -632,6 +632,9 @@ static const struct proto_ops pptp_ops = {
 	.recvmsg    = sock_no_recvmsg,
 	.mmap       = sock_no_mmap,
 	.ioctl      = pppox_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = pppox_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppox_pptp_proto = {
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index a8bb193fdfd5..142ca673b9cc 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -864,39 +864,8 @@ COMPATIBLE_IOCTL(SG_SET_KEEP_ORPHAN)
 COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
 #endif
 /* PPP stuff */
-COMPATIBLE_IOCTL(PPPIOCGFLAGS)
-COMPATIBLE_IOCTL(PPPIOCSFLAGS)
-COMPATIBLE_IOCTL(PPPIOCGASYNCMAP)
-COMPATIBLE_IOCTL(PPPIOCSASYNCMAP)
 COMPATIBLE_IOCTL(PPPIOCGUNIT)
-COMPATIBLE_IOCTL(PPPIOCGRASYNCMAP)
-COMPATIBLE_IOCTL(PPPIOCSRASYNCMAP)
-COMPATIBLE_IOCTL(PPPIOCGMRU)
-COMPATIBLE_IOCTL(PPPIOCSMRU)
-COMPATIBLE_IOCTL(PPPIOCSMAXCID)
-COMPATIBLE_IOCTL(PPPIOCGXASYNCMAP)
-COMPATIBLE_IOCTL(PPPIOCSXASYNCMAP)
-COMPATIBLE_IOCTL(PPPIOCXFERUNIT)
-/* PPPIOCSCOMPRESS is translated */
-COMPATIBLE_IOCTL(PPPIOCGNPMODE)
-COMPATIBLE_IOCTL(PPPIOCSNPMODE)
-COMPATIBLE_IOCTL(PPPIOCGDEBUG)
-COMPATIBLE_IOCTL(PPPIOCSDEBUG)
-/* PPPIOCSPASS is translated */
-/* PPPIOCSACTIVE is translated */
-/* PPPIOCGIDLE is translated */
-COMPATIBLE_IOCTL(PPPIOCNEWUNIT)
-COMPATIBLE_IOCTL(PPPIOCATTACH)
-COMPATIBLE_IOCTL(PPPIOCDETACH)
-COMPATIBLE_IOCTL(PPPIOCSMRRU)
-COMPATIBLE_IOCTL(PPPIOCCONNECT)
-COMPATIBLE_IOCTL(PPPIOCDISCONN)
-COMPATIBLE_IOCTL(PPPIOCATTCHAN)
 COMPATIBLE_IOCTL(PPPIOCGCHAN)
-COMPATIBLE_IOCTL(PPPIOCGL2TPSTATS)
-/* PPPOX */
-COMPATIBLE_IOCTL(PPPOEIOCSFWD32)
-COMPATIBLE_IOCTL(PPPOEIOCDFWD)
 /* Big A */
 /* sparc only */
 /* Big Q for sound/OSS */
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 04d9946dcdba..8ef66513fbe0 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -1686,6 +1686,9 @@ static const struct proto_ops pppol2tp_ops = {
 	.recvmsg	= pppol2tp_recvmsg,
 	.mmap		= sock_no_mmap,
 	.ioctl		= pppox_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = pppox_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppol2tp_proto = {
-- 
2.18.0