compat_ioctl: move simple ppp command handling into drivercompat-ioctl-ppp

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@arndb.de>

6 files changed, 16 insertions, 32 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index f32420c5c5a77e..1379d5c19ac98e 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -903,6 +903,9 @@ static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long
 out:
 	mutex_unlock(&ppp_mutex);
 
+	if (err == -ENOIOCTLCMD)
+		err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+
 	return err;
 }
 #endif
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index c5e7435db86cca..f4dc551196af97 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -1124,6 +1124,9 @@ static const struct proto_ops pppoe_ops = {
 	.recvmsg	= pppoe_recvmsg,
 	.mmap		= sock_no_mmap,
 	.ioctl		= pppox_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= pppox_compat_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppoe_proto = {
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 50c60550f295da..b626001c0e2b4c 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -628,6 +628,9 @@ static const struct proto_ops pptp_ops = {
 	.recvmsg    = sock_no_recvmsg,
 	.mmap       = sock_no_mmap,
 	.ioctl      = pppox_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = pppox_compat_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppox_pptp_proto = {
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c31978de677bab..e6dbd956cf6601 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -515,40 +515,8 @@ 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 */
-COMPATIBLE_IOCTL(PPPIOCGIDLE32)
-COMPATIBLE_IOCTL(PPPIOCGIDLE64)
-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/include/linux/if_pppox.h b/include/linux/if_pppox.h
index d221f1465f41b3..ceed206ac4c1d9 100644
--- a/include/linux/if_pppox.h
+++ b/include/linux/if_pppox.h
@@ -84,6 +84,10 @@ extern int register_pppox_proto(int proto_num, const struct pppox_proto *pp);
 extern void unregister_pppox_proto(int proto_num);
 extern void pppox_unbind_sock(struct sock *sk);/* delete ppp-channel binding */
 extern int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
+static inline int pppox_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	return pppox_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
+}
 
 #define PPPOEIOCSFWD32    _IOW(0xB1 ,0, compat_size_t)
 
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 04d9946dcdba64..3983c125966748 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_compat_ioctl,
+#endif
 };
 
 static const struct pppox_proto pppol2tp_proto = {