Merge branch 'uaccess.csum' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull uaccess/csum updates from Al Viro:
 "Regularize the sitation with uaccess checksum primitives:

   - fold csum_partial_... into csum_and_copy_..._user()

   - on x86 collapse several access_ok()/stac()/clac() into
     user_access_begin()/user_access_end()"

* 'uaccess.csum' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  default csum_and_copy_to_user(): don't bother with access_ok()
  take the dummy csum_and_copy_from_user() into net/checksum.h
  arm: switch to csum_and_copy_from_user()
  sh32: convert to csum_and_copy_from_user()
  m68k: convert to csum_and_copy_from_user()
  xtensa: switch to providing csum_and_copy_from_user()
  sparc: switch to providing csum_and_copy_from_user()
  parisc: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  ia64: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  ia64: csum_partial_copy_nocheck(): don't abuse csum_partial_copy_from_user()
  x86: switch 32bit csum_and_copy_to_user() to user_access_{begin,end}()
  x86: switch both 32bit and 64bit to providing csum_and_copy_from_user()
  x86_64: csum_..._copy_..._user(): switch to unsafe_..._user()
  get rid of csum_partial_copy_to_user()

3 files changed, 15 insertions, 20 deletions

diff --git a/arch/x86/include/asm/checksum.h b/arch/x86/include/asm/checksum.h
index d79d1e622dcf..0ada98d5d09f 100644
--- a/arch/x86/include/asm/checksum.h
+++ b/arch/x86/include/asm/checksum.h
@@ -1,4 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#define  _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
+#define HAVE_CSUM_COPY_USER
 #ifdef CONFIG_X86_32
 # include <asm/checksum_32.h>
 #else
diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h
index f57b94e02c57..11624c8a9d8d 100644
--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -44,18 +44,21 @@ static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst,
 	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
 }
 
-static inline __wsum csum_partial_copy_from_user(const void __user *src,
-						 void *dst,
-						 int len, __wsum sum,
-						 int *err_ptr)
+static inline __wsum csum_and_copy_from_user(const void __user *src,
+					     void *dst, int len,
+					     __wsum sum, int *err_ptr)
 {
 	__wsum ret;
 
 	might_sleep();
-	stac();
+	if (!user_access_begin(src, len)) {
+		if (len)
+			*err_ptr = -EFAULT;
+		return sum;
+	}
 	ret = csum_partial_copy_generic((__force void *)src, dst,
 					len, sum, err_ptr, NULL);
-	clac();
+	user_access_end();
 
 	return ret;
 }
@@ -173,7 +176,6 @@ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 /*
  *	Copy and checksum to user
  */
-#define HAVE_CSUM_COPY_USER
 static inline __wsum csum_and_copy_to_user(const void *src,
 					   void __user *dst,
 					   int len, __wsum sum,
@@ -182,11 +184,10 @@ static inline __wsum csum_and_copy_to_user(const void *src,
 	__wsum ret;
 
 	might_sleep();
-	if (access_ok(dst, len)) {
-		stac();
+	if (user_access_begin(dst, len)) {
 		ret = csum_partial_copy_generic(src, (__force void *)dst,
 						len, sum, NULL, err_ptr);
-		clac();
+		user_access_end();
 		return ret;
 	}
 
diff --git a/arch/x86/include/asm/checksum_64.h b/arch/x86/include/asm/checksum_64.h
index 3ec6d3267cf9..0a289b87e872 100644
--- a/arch/x86/include/asm/checksum_64.h
+++ b/arch/x86/include/asm/checksum_64.h
@@ -129,27 +129,19 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  */
 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
 
-#define  _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
-#define HAVE_CSUM_COPY_USER 1
-
-
 /* Do not call this directly. Use the wrappers below */
 extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst,
 					int len, __wsum sum,
 					int *src_err_ptr, int *dst_err_ptr);
 
 
-extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
 					  int len, __wsum isum, int *errp);
-extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
+extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
 					int len, __wsum isum, int *errp);
 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
 					int len, __wsum sum);
 
-/* Old names. To be removed. */
-#define csum_and_copy_to_user csum_partial_copy_to_user
-#define csum_and_copy_from_user csum_partial_copy_from_user
-
 /**
  * ip_compute_csum - Compute an 16bit IP checksum.
  * @buff: buffer address.