Merge branch 'net-remove-compat-alloc-user-space'

Arnd Bergmann says:

====================
remove compat_alloc_user_space()

This is the fifth version of my series, now spanning four patches
instead of two, with a new approach for handling struct ifreq
compatibility after I realized that my earlier approach introduces
additional problems.

The idea here is to always push down the compat conversion
deeper into the call stack: rather than pretending to be
native mode with a modified copy of the original data on
the user space stack, have the code that actually works on
the data understand the difference between native and compat
versions.

I have spent a long time looking at all drivers that implement
an ndo_do_ioctl callback to verify that my assumptions are
correct. This has led to a series of ~30 additional patches
that I am not including here but will post separately, fixing
a number of bugs in SIOCDEVPRIVATE ioctls, removing dead
code, and splitting ndo_do_ioctl into multiple new ndo callbacks
for private and ethernet specific commands.

      Arnd

Link: https://lore.kernel.org/netdev/20201124151828.169152-1-arnd@kernel.org/

Changes in v6:
 - Split out and expand linux/compat.h rework
 - Split ifconf change into two patches
 - Rebase on latest net-next/master

Changes in v5:
 - Rebase to v5.14-rc2
 - Fix a few build issues

Changes in v4:
 - build fix without CONFIG_INET
 - build fix without CONFIG_COMPAT
 - style fixes pointed out by hch

Changes in v3:
 - complete rewrite of the series
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 44 insertions, 30 deletions

diff --git a/include/asm-generic/compat.h b/include/asm-generic/compat.h
index 30f7b18a36f9..d46c0201cc34 100644
--- a/include/asm-generic/compat.h
+++ b/include/asm-generic/compat.h
@@ -20,7 +20,18 @@ typedef u16 compat_ushort_t;
 typedef u32 compat_uint_t;
 typedef u32 compat_ulong_t;
 typedef u32 compat_uptr_t;
+typedef u32 compat_caddr_t;
 typedef u32 compat_aio_context_t;
+typedef u32 compat_old_sigset_t;
+
+#ifndef __compat_uid32_t
+typedef u32 __compat_uid32_t;
+typedef u32 __compat_gid32_t;
+#endif
+
+#ifndef compat_mode_t
+typedef u32 compat_mode_t;
+#endif
 
 #ifdef CONFIG_COMPAT_FOR_U64_ALIGNMENT
 typedef s64 __attribute__((aligned(4))) compat_s64;
@@ -30,4 +41,10 @@ typedef s64 compat_s64;
 typedef u64 compat_u64;
 #endif
 
+#ifndef _COMPAT_NSIG
+typedef u32 compat_sigset_word;
+#define _COMPAT_NSIG _NSIG
+#define _COMPAT_NSIG_BPW 32
+#endif
+
 #endif
diff --git a/include/linux/compat.h b/include/linux/compat.h
index c270124e4402..8e0598c7d1d1 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -20,11 +20,8 @@
 #include <linux/unistd.h>
 
 #include <asm/compat.h>
-
-#ifdef CONFIG_COMPAT
 #include <asm/siginfo.h>
 #include <asm/signal.h>
-#endif
 
 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 /*
@@ -95,8 +92,6 @@ struct compat_iovec {
 	compat_size_t	iov_len;
 };
 
-#ifdef CONFIG_COMPAT
-
 #ifndef compat_user_stack_pointer
 #define compat_user_stack_pointer() current_user_stack_pointer()
 #endif
@@ -131,9 +126,11 @@ struct compat_tms {
 
 #define _COMPAT_NSIG_WORDS	(_COMPAT_NSIG / _COMPAT_NSIG_BPW)
 
+#ifndef compat_sigset_t
 typedef struct {
 	compat_sigset_word	sig[_COMPAT_NSIG_WORDS];
 } compat_sigset_t;
+#endif
 
 int set_compat_user_sigmask(const compat_sigset_t __user *umask,
 			    size_t sigsetsize);
@@ -384,6 +381,7 @@ struct compat_keyctl_kdf_params {
 	__u32 __spare[8];
 };
 
+struct compat_stat;
 struct compat_statfs;
 struct compat_statfs64;
 struct compat_old_linux_dirent;
@@ -428,7 +426,7 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
 		  unsigned int size)
 {
 	/* size <= sizeof(compat_sigset_t) <= sizeof(sigset_t) */
-#ifdef __BIG_ENDIAN
+#if defined(__BIG_ENDIAN) && defined(CONFIG_64BIT)
 	compat_sigset_t v;
 	switch (_NSIG_WORDS) {
 	case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
@@ -929,17 +927,6 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
 
 #endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
 
-
-/*
- * For most but not all architectures, "am I in a compat syscall?" and
- * "am I a compat task?" are the same question.  For architectures on which
- * they aren't the same question, arch code can override in_compat_syscall.
- */
-
-#ifndef in_compat_syscall
-static inline bool in_compat_syscall(void) { return is_compat_task(); }
-#endif
-
 /**
  * ns_to_old_timeval32 - Compat version of ns_to_timeval
  * @nsec:	the nanoseconds value to be converted
@@ -969,6 +956,17 @@ int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz,
 int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz,
 			  struct compat_statfs64 __user * buf);
 
+#ifdef CONFIG_COMPAT
+
+/*
+ * For most but not all architectures, "am I in a compat syscall?" and
+ * "am I a compat task?" are the same question.  For architectures on which
+ * they aren't the same question, arch code can override in_compat_syscall.
+ */
+#ifndef in_compat_syscall
+static inline bool in_compat_syscall(void) { return is_compat_task(); }
+#endif
+
 #else /* !CONFIG_COMPAT */
 
 #define is_compat_task() (0)
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 232daaec56e4..4711b96dae0c 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -17,8 +17,6 @@
 #include <linux/compat.h>
 #include <uapi/linux/ethtool.h>
 
-#ifdef CONFIG_COMPAT
-
 struct compat_ethtool_rx_flow_spec {
 	u32		flow_type;
 	union ethtool_flow_union h_u;
@@ -38,8 +36,6 @@ struct compat_ethtool_rxnfc {
 	u32				rule_locs[];
 };
 
-#endif /* CONFIG_COMPAT */
-
 #include <linux/rculist.h>
 
 /**
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 53aa0343bf69..67e042932681 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -178,6 +178,15 @@ static inline struct net_device *ip_dev_find(struct net *net, __be32 addr)
 
 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b);
 int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *);
+#ifdef CONFIG_INET
+int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size);
+#else
+static inline int inet_gifconf(struct net_device *dev, char __user *buf,
+			       int len, int size)
+{
+	return 0;
+}
+#endif
 void devinet_init(void);
 struct in_device *inetdev_by_index(struct net *, int);
 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 42f6f866d5f3..c871dc223dfa 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3289,14 +3289,6 @@ static inline bool dev_has_header(const struct net_device *dev)
 	return dev->header_ops && dev->header_ops->create;
 }
 
-typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr,
-			   int len, int size);
-int register_gifconf(unsigned int family, gifconf_func_t *gifconf);
-static inline int unregister_gifconf(unsigned int family)
-{
-	return register_gifconf(family, NULL);
-}
-
 #ifdef CONFIG_NET_FLOW_LIMIT
 #define FLOW_LIMIT_HISTORY	(1 << 7)  /* must be ^2 and !overflow buckets */
 struct sd_flow_limit {
@@ -4014,9 +4006,11 @@ int netdev_rx_handler_register(struct net_device *dev,
 void netdev_rx_handler_unregister(struct net_device *dev);
 
 bool dev_valid_name(const char *name);
+int get_user_ifreq(struct ifreq *ifr, void __user **ifrdata, void __user *arg);
+int put_user_ifreq(struct ifreq *ifr, void __user *arg);
 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
 		bool *need_copyout);
-int dev_ifconf(struct net *net, struct ifconf *, int);
+int dev_ifconf(struct net *net, struct ifconf __user *ifc);
 int dev_ethtool(struct net *net, struct ifreq *);
 unsigned int dev_get_flags(const struct net_device *);
 int __dev_change_flags(struct net_device *dev, unsigned int flags,