x86: switch to RAW_COPY_USER

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/x86/Kconfig

@@ -175,6 +175,7 @@ config X86
 	select USER_STACKTRACE_SUPPORT
 	select VIRT_TO_BUS
 	select X86_FEATURE_NAMES		if PROC_FS
+	select ARCH_HAS_RAW_COPY_USER
 
 config INSTRUCTION_DECODER
 	def_bool y

arch/x86/include/asm/uaccess.h

@@ -682,59 +682,6 @@ extern struct movsl_mask {
 # include <asm/uaccess_64.h>
 #endif
 
-unsigned long __must_check _copy_from_user(void *to, const void __user *from,
-					   unsigned n);
-unsigned long __must_check _copy_to_user(void __user *to, const void *from,
-					 unsigned n);
-
-extern void __compiletime_error("usercopy buffer size is too small")
-__bad_copy_user(void);
-
-static inline void copy_user_overflow(int size, unsigned long count)
-{
-	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
-}
-
-static __always_inline unsigned long __must_check
-copy_from_user(void *to, const void __user *from, unsigned long n)
-{
-	int sz = __compiletime_object_size(to);
-
-	might_fault();
-
-	kasan_check_write(to, n);
-
-	if (likely(sz < 0 || sz >= n)) {
-		check_object_size(to, n, false);
-		n = _copy_from_user(to, from, n);
-	} else if (!__builtin_constant_p(n))
-		copy_user_overflow(sz, n);
-	else
-		__bad_copy_user();
-
-	return n;
-}
-
-static __always_inline unsigned long __must_check
-copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-	int sz = __compiletime_object_size(from);
-
-	kasan_check_read(from, n);
-
-	might_fault();
-
-	if (likely(sz < 0 || sz >= n)) {
-		check_object_size(from, n, true);
-		n = _copy_to_user(to, from, n);
-	} else if (!__builtin_constant_p(n))
-		copy_user_overflow(sz, n);
-	else
-		__bad_copy_user();
-
-	return n;
-}
-
 /*
  * We rely on the nested NMI work to allow atomic faults from the NMI path; the
  * nested NMI paths are careful to preserve CR2.

arch/x86/include/asm/uaccess_32.h

@@ -8,113 +8,48 @@
 #include <asm/asm.h>
 #include <asm/page.h>
 
-unsigned long __must_check __copy_to_user_ll
-		(void __user *to, const void *from, unsigned long n);
-unsigned long __must_check __copy_from_user_ll
-		(void *to, const void __user *from, unsigned long n);
-unsigned long __must_check __copy_from_user_ll_nozero
-		(void *to, const void __user *from, unsigned long n);
+unsigned long __must_check __copy_user_ll
+		(void *to, const void *from, unsigned long n);
 unsigned long __must_check __copy_from_user_ll_nocache_nozero
 		(void *to, const void __user *from, unsigned long n);
 
-/**
- * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only.
- *
- * Copy data from kernel space to user space.  Caller must check
- * the specified block with access_ok() before calling this function.
- * The caller should also make sure he pins the user space address
- * so that we don't result in page fault and sleep.
- */
 static __always_inline unsigned long __must_check
-__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	check_object_size(from, n, true);
-	return __copy_to_user_ll(to, from, n);
+	return __copy_user_ll((__force void *)to, from, n);
 }
 
-/**
- * __copy_to_user: - Copy a block of data into user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-static __always_inline unsigned long __must_check
-__copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-	might_fault();
-	return __copy_to_user_inatomic(to, from, n);
-}
-
-static __always_inline unsigned long
-__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
-{
-	return __copy_from_user_ll_nozero(to, from, n);
-}
-
-/**
- * __copy_from_user: - Copy a block of data from user space, with less checking.
- * @to:   Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- *
- * An alternate version - __copy_from_user_inatomic() - may be called from
- * atomic context and will fail rather than sleep.  In this case the
- * uncopied bytes will *NOT* be padded with zeros.  See fs/filemap.h
- * for explanation of why this is needed.
- */
 static __always_inline unsigned long
-__copy_from_user(void *to, const void __user *from, unsigned long n)
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	might_fault();
-	check_object_size(to, n, false);
 	if (__builtin_constant_p(n)) {
 		unsigned long ret;
 
 		switch (n) {
 		case 1:
+			ret = 0;
 			__uaccess_begin();
-			__get_user_size(*(u8 *)to, from, 1, ret, 1);
+			__get_user_asm_nozero(*(u8 *)to, from, ret,
+					      "b", "b", "=q", 1);
 			__uaccess_end();
 			return ret;
 		case 2:
+			ret = 0;
 			__uaccess_begin();
-			__get_user_size(*(u16 *)to, from, 2, ret, 2);
+			__get_user_asm_nozero(*(u16 *)to, from, ret,
+					      "w", "w", "=r", 2);
 			__uaccess_end();
 			return ret;
 		case 4:
+			ret = 0;
 			__uaccess_begin();
-			__get_user_size(*(u32 *)to, from, 4, ret, 4);
+			__get_user_asm_nozero(*(u32 *)to, from, ret,
+					      "l", "k", "=r", 4);
 			__uaccess_end();
 			return ret;
 		}
 	}
-	return __copy_from_user_ll(to, from, n);
+	return __copy_user_ll(to, (__force const void *)from, n);
 }
 
 static __always_inline unsigned long

arch/x86/include/asm/uaccess_64.h

@@ -45,15 +45,11 @@ copy_user_generic(void *to, const void *from, unsigned len)
 	return ret;
 }
 
-__must_check unsigned long
-copy_in_user(void __user *to, const void __user *from, unsigned len);
-
-static __always_inline __must_check
-int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
+static __always_inline __must_check unsigned long
+raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
 {
 	int ret = 0;
 
-	check_object_size(dst, size, false);
 	if (!__builtin_constant_p(size))
 		return copy_user_generic(dst, (__force void *)src, size);
 	switch (size) {
@@ -106,20 +102,11 @@ int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
 	}
 }
 
-static __always_inline __must_check
-int __copy_from_user(void *dst, const void __user *src, unsigned size)
-{
-	might_fault();
-	kasan_check_write(dst, size);
-	return __copy_from_user_nocheck(dst, src, size);
-}
-
-static __always_inline __must_check
-int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
+static __always_inline __must_check unsigned long
+raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
 {
 	int ret = 0;
 
-	check_object_size(src, size, true);
 	if (!__builtin_constant_p(size))
 		return copy_user_generic((__force void *)dst, src, size);
 	switch (size) {
@@ -175,34 +162,12 @@ int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
 }
 
 static __always_inline __must_check
-int __copy_to_user(void __user *dst, const void *src, unsigned size)
-{
-	might_fault();
-	kasan_check_read(src, size);
-	return __copy_to_user_nocheck(dst, src, size);
-}
-
-static __always_inline __must_check
-int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
+unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long size)
 {
 	return copy_user_generic((__force void *)dst,
 				 (__force void *)src, size);
 }
 
-static __must_check __always_inline int
-__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
-{
-	kasan_check_write(dst, size);
-	return __copy_from_user_nocheck(dst, src, size);
-}
-
-static __must_check __always_inline int
-__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
-{
-	kasan_check_read(src, size);
-	return __copy_to_user_nocheck(dst, src, size);
-}
-
 extern long __copy_user_nocache(void *dst, const void __user *src,
 				unsigned size, int zerorest);
 

arch/x86/lib/usercopy.c

@@ -4,12 +4,9 @@
  *  For licencing details see kernel-base/COPYING
  */
 
-#include <linux/highmem.h>
+#include <linux/uaccess.h>
 #include <linux/export.h>
 
-#include <asm/word-at-a-time.h>
-#include <linux/sched.h>
-
 /*
  * We rely on the nested NMI work to allow atomic faults from the NMI path; the
  * nested NMI paths are careful to preserve CR2.
@@ -34,53 +31,3 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(copy_from_user_nmi);
-
-/**
- * copy_to_user: - Copy a block of data into user space.
- * @to:   Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-unsigned long _copy_to_user(void __user *to, const void *from, unsigned n)
-{
-	if (access_ok(VERIFY_WRITE, to, n))
-		n = __copy_to_user(to, from, n);
-	return n;
-}
-EXPORT_SYMBOL(_copy_to_user);
-
-/**
- * copy_from_user: - Copy a block of data from user space.
- * @to:   Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- */
-unsigned long _copy_from_user(void *to, const void __user *from, unsigned n)
-{
-	unsigned long res = n;
-	if (access_ok(VERIFY_READ, from, n))
-		res = __copy_from_user_inatomic(to, from, n);
-	if (unlikely(res))
-		memset(to + n - res, 0, res);
-	return res;
-}
-EXPORT_SYMBOL(_copy_from_user);

arch/x86/lib/usercopy_32.c

@@ -5,12 +5,7 @@
  * Copyright 1997 Andi Kleen <ak@muc.de>
  * Copyright 1997 Linus Torvalds
  */
-#include <linux/mm.h>
-#include <linux/highmem.h>
-#include <linux/blkdev.h>
 #include <linux/export.h>
-#include <linux/backing-dev.h>
-#include <linux/interrupt.h>
 #include <linux/uaccess.h>
 #include <asm/mmx.h>
 #include <asm/asm.h>
@@ -201,98 +196,6 @@ __copy_user_intel(void __user *to, const void *from, unsigned long size)
 	return size;
 }
 
-static unsigned long
-__copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
-{
-	int d0, d1;
-	__asm__ __volatile__(
-		       "        .align 2,0x90\n"
-		       "0:      movl 32(%4), %%eax\n"
-		       "        cmpl $67, %0\n"
-		       "        jbe 2f\n"
-		       "1:      movl 64(%4), %%eax\n"
-		       "        .align 2,0x90\n"
-		       "2:      movl 0(%4), %%eax\n"
-		       "21:     movl 4(%4), %%edx\n"
-		       "        movl %%eax, 0(%3)\n"
-		       "        movl %%edx, 4(%3)\n"
-		       "3:      movl 8(%4), %%eax\n"
-		       "31:     movl 12(%4),%%edx\n"
-		       "        movl %%eax, 8(%3)\n"
-		       "        movl %%edx, 12(%3)\n"
-		       "4:      movl 16(%4), %%eax\n"
-		       "41:     movl 20(%4), %%edx\n"
-		       "        movl %%eax, 16(%3)\n"
-		       "        movl %%edx, 20(%3)\n"
-		       "10:     movl 24(%4), %%eax\n"
-		       "51:     movl 28(%4), %%edx\n"
-		       "        movl %%eax, 24(%3)\n"
-		       "        movl %%edx, 28(%3)\n"
-		       "11:     movl 32(%4), %%eax\n"
-		       "61:     movl 36(%4), %%edx\n"
-		       "        movl %%eax, 32(%3)\n"
-		       "        movl %%edx, 36(%3)\n"
-		       "12:     movl 40(%4), %%eax\n"
-		       "71:     movl 44(%4), %%edx\n"
-		       "        movl %%eax, 40(%3)\n"
-		       "        movl %%edx, 44(%3)\n"
-		       "13:     movl 48(%4), %%eax\n"
-		       "81:     movl 52(%4), %%edx\n"
-		       "        movl %%eax, 48(%3)\n"
-		       "        movl %%edx, 52(%3)\n"
-		       "14:     movl 56(%4), %%eax\n"
-		       "91:     movl 60(%4), %%edx\n"
-		       "        movl %%eax, 56(%3)\n"
-		       "        movl %%edx, 60(%3)\n"
-		       "        addl $-64, %0\n"
-		       "        addl $64, %4\n"
-		       "        addl $64, %3\n"
-		       "        cmpl $63, %0\n"
-		       "        ja  0b\n"
-		       "5:      movl  %0, %%eax\n"
-		       "        shrl  $2, %0\n"
-		       "        andl $3, %%eax\n"
-		       "        cld\n"
-		       "6:      rep; movsl\n"
-		       "        movl %%eax,%0\n"
-		       "7:      rep; movsb\n"
-		       "8:\n"
-		       ".section .fixup,\"ax\"\n"
-		       "9:      lea 0(%%eax,%0,4),%0\n"
-		       "16:     pushl %0\n"
-		       "        pushl %%eax\n"
-		       "        xorl %%eax,%%eax\n"
-		       "        rep; stosb\n"
-		       "        popl %%eax\n"
-		       "        popl %0\n"
-		       "        jmp 8b\n"
-		       ".previous\n"
-		       _ASM_EXTABLE(0b,16b)
-		       _ASM_EXTABLE(1b,16b)
-		       _ASM_EXTABLE(2b,16b)
-		       _ASM_EXTABLE(21b,16b)
-		       _ASM_EXTABLE(3b,16b)
-		       _ASM_EXTABLE(31b,16b)
-		       _ASM_EXTABLE(4b,16b)
-		       _ASM_EXTABLE(41b,16b)
-		       _ASM_EXTABLE(10b,16b)
-		       _ASM_EXTABLE(51b,16b)
-		       _ASM_EXTABLE(11b,16b)
-		       _ASM_EXTABLE(61b,16b)
-		       _ASM_EXTABLE(12b,16b)
-		       _ASM_EXTABLE(71b,16b)
-		       _ASM_EXTABLE(13b,16b)
-		       _ASM_EXTABLE(81b,16b)
-		       _ASM_EXTABLE(14b,16b)
-		       _ASM_EXTABLE(91b,16b)
-		       _ASM_EXTABLE(6b,9b)
-		       _ASM_EXTABLE(7b,16b)
-		       : "=&c"(size), "=&D" (d0), "=&S" (d1)
-		       :  "1"(to), "2"(from), "0"(size)
-		       : "eax", "edx", "memory");
-	return size;
-}
-
 static unsigned long __copy_user_intel_nocache(void *to,
 				const void __user *from, unsigned long size)
 {
@@ -387,8 +290,6 @@ static unsigned long __copy_user_intel_nocache(void *to,
  * Leave these declared but undefined.  They should not be any references to
  * them
  */
-unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
-					unsigned long size);
 unsigned long __copy_user_intel(void __user *to, const void *from,
 					unsigned long size);
 #endif /* CONFIG_X86_INTEL_USERCOPY */
@@ -427,47 +328,7 @@ do {									\
 		: "memory");						\
 } while (0)
 
-#define __copy_user_zeroing(to, from, size)				\
-do {									\
-	int __d0, __d1, __d2;						\
-	__asm__ __volatile__(						\
-		"	cmp  $7,%0\n"					\
-		"	jbe  1f\n"					\
-		"	movl %1,%0\n"					\
-		"	negl %0\n"					\
-		"	andl $7,%0\n"					\
-		"	subl %0,%3\n"					\
-		"4:	rep; movsb\n"					\
-		"	movl %3,%0\n"					\
-		"	shrl $2,%0\n"					\
-		"	andl $3,%3\n"					\
-		"	.align 2,0x90\n"				\
-		"0:	rep; movsl\n"					\
-		"	movl %3,%0\n"					\
-		"1:	rep; movsb\n"					\
-		"2:\n"							\
-		".section .fixup,\"ax\"\n"				\
-		"5:	addl %3,%0\n"					\
-		"	jmp 6f\n"					\
-		"3:	lea 0(%3,%0,4),%0\n"				\
-		"6:	pushl %0\n"					\
-		"	pushl %%eax\n"					\
-		"	xorl %%eax,%%eax\n"				\
-		"	rep; stosb\n"					\
-		"	popl %%eax\n"					\
-		"	popl %0\n"					\
-		"	jmp 2b\n"					\
-		".previous\n"						\
-		_ASM_EXTABLE(4b,5b)					\
-		_ASM_EXTABLE(0b,3b)					\
-		_ASM_EXTABLE(1b,6b)					\
-		: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)	\
-		: "3"(size), "0"(size), "1"(to), "2"(from)		\
-		: "memory");						\
-} while (0)
-
-unsigned long __copy_to_user_ll(void __user *to, const void *from,
-				unsigned long n)
+unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
 {
 	stac();
 	if (movsl_is_ok(to, from, n))
@@ -477,34 +338,7 @@ unsigned long __copy_to_user_ll(void __user *to, const void *from,
 	clac();
 	return n;
 }
-EXPORT_SYMBOL(__copy_to_user_ll);
-
-unsigned long __copy_from_user_ll(void *to, const void __user *from,
-					unsigned long n)
-{
-	stac();
-	if (movsl_is_ok(to, from, n))
-		__copy_user_zeroing(to, from, n);
-	else
-		n = __copy_user_zeroing_intel(to, from, n);
-	clac();
-	return n;
-}
-EXPORT_SYMBOL(__copy_from_user_ll);
-
-unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
-					 unsigned long n)
-{
-	stac();
-	if (movsl_is_ok(to, from, n))
-		__copy_user(to, from, n);
-	else
-		n = __copy_user_intel((void __user *)to,
-				      (const void *)from, n);
-	clac();
-	return n;
-}
-EXPORT_SYMBOL(__copy_from_user_ll_nozero);
+EXPORT_SYMBOL(__copy_user_ll);
 
 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
 					unsigned long n)