diff mbox series

[v3,4/7] x86: introduce _ASM_EXTABLE_UA for uaccess fixups

Message ID 20180828201421.157735-5-jannh@google.com (mailing list archive)
State New, archived
Headers show
Series x86: BUG() on #GP / kernel #PF in uaccess | expand

Commit Message

Jann Horn Aug. 28, 2018, 8:14 p.m. UTC 
Currently, most fixups for attempting to access userspace memory are
handled using _ASM_EXTABLE, which is also used for various other types of
fixups (e.g. safe MSR access, IRET failures, and a bunch of other things).
In order to make it possible to add special safety checks to uaccess fixups
(in particular, checking whether the fault address is actually in
userspace), introduce a new exception table handler ex_handler_uaccess()
and wire it up to all the user access fixups (excluding ones that
already use _ASM_EXTABLE_EX).

Signed-off-by: Jann Horn <jannh@google.com>
---
NOTE: I haven't touched the two uaccess fixups in asm/fpu/internal.h
because I'm not sure about what other kinds of exceptions those might
have to handle.

 arch/x86/include/asm/asm.h          |  10 ++-
 arch/x86/include/asm/fpu/internal.h |   2 +-
 arch/x86/include/asm/futex.h        |   6 +-
 arch/x86/include/asm/uaccess.h      |  22 ++---
 arch/x86/lib/checksum_32.S          |   4 +-
 arch/x86/lib/copy_user_64.S         |  90 ++++++++++----------
 arch/x86/lib/csum-copy_64.S         |   8 +-
 arch/x86/lib/getuser.S              |  12 +--
 arch/x86/lib/putuser.S              |  10 +--
 arch/x86/lib/usercopy_32.c          | 126 ++++++++++++++--------------
 arch/x86/lib/usercopy_64.c          |   4 +-
 arch/x86/mm/extable.c               |   8 ++
 12 files changed, 160 insertions(+), 142 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 990770f9e76b..6467757bb39f 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -130,6 +130,9 @@ 
 # define _ASM_EXTABLE(from, to)					\
 	_ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
 
+# define _ASM_EXTABLE_UA(from, to)				\
+	_ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
+
 # define _ASM_EXTABLE_FAULT(from, to)				\
 	_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
 
@@ -165,8 +168,8 @@ 
 	jmp copy_user_handle_tail
 	.previous
 
-	_ASM_EXTABLE(100b,103b)
-	_ASM_EXTABLE(101b,103b)
+	_ASM_EXTABLE_UA(100b, 103b)
+	_ASM_EXTABLE_UA(101b, 103b)
 	.endm
 
 #else
@@ -182,6 +185,9 @@ 
 # define _ASM_EXTABLE(from, to)					\
 	_ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
 
+# define _ASM_EXTABLE_UA(from, to)				\
+	_ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
+
 # define _ASM_EXTABLE_FAULT(from, to)				\
 	_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
 
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index a38bf5a1e37a..068ff7689268 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -226,7 +226,7 @@  static inline void copy_fxregs_to_kernel(struct fpu *fpu)
 		     "3: movl $-2,%[err]\n\t"				\
 		     "jmp 2b\n\t"					\
 		     ".popsection\n\t"					\
-		     _ASM_EXTABLE(1b, 3b)				\
+		     _ASM_EXTABLE_UA(1b, 3b)				\
 		     : [err] "=r" (err)					\
 		     : "D" (st), "m" (*st), "a" (lmask), "d" (hmask)	\
 		     : "memory")
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index de4d68852d3a..13c83fe97988 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -20,7 +20,7 @@ 
 		     "3:\tmov\t%3, %1\n"			\
 		     "\tjmp\t2b\n"				\
 		     "\t.previous\n"				\
-		     _ASM_EXTABLE(1b, 3b)			\
+		     _ASM_EXTABLE_UA(1b, 3b)			\
 		     : "=r" (oldval), "=r" (ret), "+m" (*uaddr)	\
 		     : "i" (-EFAULT), "0" (oparg), "1" (0))
 
@@ -36,8 +36,8 @@ 
 		     "4:\tmov\t%5, %1\n"			\
 		     "\tjmp\t3b\n"				\
 		     "\t.previous\n"				\
-		     _ASM_EXTABLE(1b, 4b)			\
-		     _ASM_EXTABLE(2b, 4b)			\
+		     _ASM_EXTABLE_UA(1b, 4b)			\
+		     _ASM_EXTABLE_UA(2b, 4b)			\
 		     : "=&a" (oldval), "=&r" (ret),		\
 		       "+m" (*uaddr), "=&r" (tem)		\
 		     : "r" (oparg), "i" (-EFAULT), "1" (0))
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index aae77eb8491c..b5e58cc0c5e7 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -198,8 +198,8 @@  __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
 		     "4:	movl %3,%0\n"				\
 		     "	jmp 3b\n"					\
 		     ".previous\n"					\
-		     _ASM_EXTABLE(1b, 4b)				\
-		     _ASM_EXTABLE(2b, 4b)				\
+		     _ASM_EXTABLE_UA(1b, 4b)				\
+		     _ASM_EXTABLE_UA(2b, 4b)				\
 		     : "=r" (err)					\
 		     : "A" (x), "r" (addr), "i" (errret), "0" (err))
 
@@ -340,8 +340,8 @@  do {									\
 		     "	xorl %%edx,%%edx\n"				\
 		     "	jmp 3b\n"					\
 		     ".previous\n"					\
-		     _ASM_EXTABLE(1b, 4b)				\
-		     _ASM_EXTABLE(2b, 4b)				\
+		     _ASM_EXTABLE_UA(1b, 4b)				\
+		     _ASM_EXTABLE_UA(2b, 4b)				\
 		     : "=r" (retval), "=&A"(x)				\
 		     : "m" (__m(__ptr)), "m" __m(((u32 __user *)(__ptr)) + 1),	\
 		       "i" (errret), "0" (retval));			\
@@ -386,7 +386,7 @@  do {									\
 		     "	xor"itype" %"rtype"1,%"rtype"1\n"		\
 		     "	jmp 2b\n"					\
 		     ".previous\n"					\
-		     _ASM_EXTABLE(1b, 3b)				\
+		     _ASM_EXTABLE_UA(1b, 3b)				\
 		     : "=r" (err), ltype(x)				\
 		     : "m" (__m(addr)), "i" (errret), "0" (err))
 
@@ -398,7 +398,7 @@  do {									\
 		     "3:	mov %3,%0\n"				\
 		     "	jmp 2b\n"					\
 		     ".previous\n"					\
-		     _ASM_EXTABLE(1b, 3b)				\
+		     _ASM_EXTABLE_UA(1b, 3b)				\
 		     : "=r" (err), ltype(x)				\
 		     : "m" (__m(addr)), "i" (errret), "0" (err))
 
@@ -474,7 +474,7 @@  struct __large_struct { unsigned long buf[100]; };
 		     "3:	mov %3,%0\n"				\
 		     "	jmp 2b\n"					\
 		     ".previous\n"					\
-		     _ASM_EXTABLE(1b, 3b)				\
+		     _ASM_EXTABLE_UA(1b, 3b)				\
 		     : "=r"(err)					\
 		     : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err))
 
@@ -602,7 +602,7 @@  extern void __cmpxchg_wrong_size(void)
 			"3:\tmov     %3, %0\n"				\
 			"\tjmp     2b\n"				\
 			"\t.previous\n"					\
-			_ASM_EXTABLE(1b, 3b)				\
+			_ASM_EXTABLE_UA(1b, 3b)				\
 			: "+r" (__ret), "=a" (__old), "+m" (*(ptr))	\
 			: "i" (-EFAULT), "q" (__new), "1" (__old)	\
 			: "memory"					\
@@ -618,7 +618,7 @@  extern void __cmpxchg_wrong_size(void)
 			"3:\tmov     %3, %0\n"				\
 			"\tjmp     2b\n"				\
 			"\t.previous\n"					\
-			_ASM_EXTABLE(1b, 3b)				\
+			_ASM_EXTABLE_UA(1b, 3b)				\
 			: "+r" (__ret), "=a" (__old), "+m" (*(ptr))	\
 			: "i" (-EFAULT), "r" (__new), "1" (__old)	\
 			: "memory"					\
@@ -634,7 +634,7 @@  extern void __cmpxchg_wrong_size(void)
 			"3:\tmov     %3, %0\n"				\
 			"\tjmp     2b\n"				\
 			"\t.previous\n"					\
-			_ASM_EXTABLE(1b, 3b)				\
+			_ASM_EXTABLE_UA(1b, 3b)				\
 			: "+r" (__ret), "=a" (__old), "+m" (*(ptr))	\
 			: "i" (-EFAULT), "r" (__new), "1" (__old)	\
 			: "memory"					\
@@ -653,7 +653,7 @@  extern void __cmpxchg_wrong_size(void)
 			"3:\tmov     %3, %0\n"				\
 			"\tjmp     2b\n"				\
 			"\t.previous\n"					\
-			_ASM_EXTABLE(1b, 3b)				\
+			_ASM_EXTABLE_UA(1b, 3b)				\
 			: "+r" (__ret), "=a" (__old), "+m" (*(ptr))	\
 			: "i" (-EFAULT), "r" (__new), "1" (__old)	\
 			: "memory"					\
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index 46e71a74e612..ad8e0906d1ea 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -273,11 +273,11 @@  unsigned int csum_partial_copy_generic (const char *src, char *dst,
 
 #define SRC(y...)			\
 	9999: y;			\
-	_ASM_EXTABLE(9999b, 6001f)
+	_ASM_EXTABLE_UA(9999b, 6001f)
 
 #define DST(y...)			\
 	9999: y;			\
-	_ASM_EXTABLE(9999b, 6002f)
+	_ASM_EXTABLE_UA(9999b, 6002f)
 
 #ifndef CONFIG_X86_USE_PPRO_CHECKSUM
 
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 020f75cc8cf6..db4e5aa0858b 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -92,26 +92,26 @@  ENTRY(copy_user_generic_unrolled)
 60:	jmp copy_user_handle_tail /* ecx is zerorest also */
 	.previous
 
-	_ASM_EXTABLE(1b,30b)
-	_ASM_EXTABLE(2b,30b)
-	_ASM_EXTABLE(3b,30b)
-	_ASM_EXTABLE(4b,30b)
-	_ASM_EXTABLE(5b,30b)
-	_ASM_EXTABLE(6b,30b)
-	_ASM_EXTABLE(7b,30b)
-	_ASM_EXTABLE(8b,30b)
-	_ASM_EXTABLE(9b,30b)
-	_ASM_EXTABLE(10b,30b)
-	_ASM_EXTABLE(11b,30b)
-	_ASM_EXTABLE(12b,30b)
-	_ASM_EXTABLE(13b,30b)
-	_ASM_EXTABLE(14b,30b)
-	_ASM_EXTABLE(15b,30b)
-	_ASM_EXTABLE(16b,30b)
-	_ASM_EXTABLE(18b,40b)
-	_ASM_EXTABLE(19b,40b)
-	_ASM_EXTABLE(21b,50b)
-	_ASM_EXTABLE(22b,50b)
+	_ASM_EXTABLE_UA(1b, 30b)
+	_ASM_EXTABLE_UA(2b, 30b)
+	_ASM_EXTABLE_UA(3b, 30b)
+	_ASM_EXTABLE_UA(4b, 30b)
+	_ASM_EXTABLE_UA(5b, 30b)
+	_ASM_EXTABLE_UA(6b, 30b)
+	_ASM_EXTABLE_UA(7b, 30b)
+	_ASM_EXTABLE_UA(8b, 30b)
+	_ASM_EXTABLE_UA(9b, 30b)
+	_ASM_EXTABLE_UA(10b, 30b)
+	_ASM_EXTABLE_UA(11b, 30b)
+	_ASM_EXTABLE_UA(12b, 30b)
+	_ASM_EXTABLE_UA(13b, 30b)
+	_ASM_EXTABLE_UA(14b, 30b)
+	_ASM_EXTABLE_UA(15b, 30b)
+	_ASM_EXTABLE_UA(16b, 30b)
+	_ASM_EXTABLE_UA(18b, 40b)
+	_ASM_EXTABLE_UA(19b, 40b)
+	_ASM_EXTABLE_UA(21b, 50b)
+	_ASM_EXTABLE_UA(22b, 50b)
 ENDPROC(copy_user_generic_unrolled)
 EXPORT_SYMBOL(copy_user_generic_unrolled)
 
@@ -156,8 +156,8 @@  ENTRY(copy_user_generic_string)
 	jmp copy_user_handle_tail
 	.previous
 
-	_ASM_EXTABLE(1b,11b)
-	_ASM_EXTABLE(3b,12b)
+	_ASM_EXTABLE_UA(1b, 11b)
+	_ASM_EXTABLE_UA(3b, 12b)
 ENDPROC(copy_user_generic_string)
 EXPORT_SYMBOL(copy_user_generic_string)
 
@@ -189,7 +189,7 @@  ENTRY(copy_user_enhanced_fast_string)
 	jmp copy_user_handle_tail
 	.previous
 
-	_ASM_EXTABLE(1b,12b)
+	_ASM_EXTABLE_UA(1b, 12b)
 ENDPROC(copy_user_enhanced_fast_string)
 EXPORT_SYMBOL(copy_user_enhanced_fast_string)
 
@@ -319,27 +319,27 @@  ENTRY(__copy_user_nocache)
 	jmp copy_user_handle_tail
 	.previous
 
-	_ASM_EXTABLE(1b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(2b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(3b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(4b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(5b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(6b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(7b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(8b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(9b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(10b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(11b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(12b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(13b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(14b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(15b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(16b,.L_fixup_4x8b_copy)
-	_ASM_EXTABLE(20b,.L_fixup_8b_copy)
-	_ASM_EXTABLE(21b,.L_fixup_8b_copy)
-	_ASM_EXTABLE(30b,.L_fixup_4b_copy)
-	_ASM_EXTABLE(31b,.L_fixup_4b_copy)
-	_ASM_EXTABLE(40b,.L_fixup_1b_copy)
-	_ASM_EXTABLE(41b,.L_fixup_1b_copy)
+	_ASM_EXTABLE_UA(1b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(2b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(3b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(4b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(5b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(6b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(7b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(8b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(9b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(10b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(11b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(12b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(13b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(14b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(15b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(16b, .L_fixup_4x8b_copy)
+	_ASM_EXTABLE_UA(20b, .L_fixup_8b_copy)
+	_ASM_EXTABLE_UA(21b, .L_fixup_8b_copy)
+	_ASM_EXTABLE_UA(30b, .L_fixup_4b_copy)
+	_ASM_EXTABLE_UA(31b, .L_fixup_4b_copy)
+	_ASM_EXTABLE_UA(40b, .L_fixup_1b_copy)
+	_ASM_EXTABLE_UA(41b, .L_fixup_1b_copy)
 ENDPROC(__copy_user_nocache)
 EXPORT_SYMBOL(__copy_user_nocache)
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S
index 45a53dfe1859..a4a379e79259 100644
--- a/arch/x86/lib/csum-copy_64.S
+++ b/arch/x86/lib/csum-copy_64.S
@@ -31,14 +31,18 @@ 
 
 	.macro source
 10:
-	_ASM_EXTABLE(10b, .Lbad_source)
+	_ASM_EXTABLE_UA(10b, .Lbad_source)
 	.endm
 
 	.macro dest
 20:
-	_ASM_EXTABLE(20b, .Lbad_dest)
+	_ASM_EXTABLE_UA(20b, .Lbad_dest)
 	.endm
 
+	/*
+	 * No _ASM_EXTABLE_UA; this is used for intentional prefetch on a
+	 * potentially unmapped kernel address.
+	 */
 	.macro ignore L=.Lignore
 30:
 	_ASM_EXTABLE(30b, \L)
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 49b167f73215..74fdff968ea3 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -132,12 +132,12 @@  bad_get_user_8:
 END(bad_get_user_8)
 #endif
 
-	_ASM_EXTABLE(1b,bad_get_user)
-	_ASM_EXTABLE(2b,bad_get_user)
-	_ASM_EXTABLE(3b,bad_get_user)
+	_ASM_EXTABLE_UA(1b, bad_get_user)
+	_ASM_EXTABLE_UA(2b, bad_get_user)
+	_ASM_EXTABLE_UA(3b, bad_get_user)
 #ifdef CONFIG_X86_64
-	_ASM_EXTABLE(4b,bad_get_user)
+	_ASM_EXTABLE_UA(4b, bad_get_user)
 #else
-	_ASM_EXTABLE(4b,bad_get_user_8)
-	_ASM_EXTABLE(5b,bad_get_user_8)
+	_ASM_EXTABLE_UA(4b, bad_get_user_8)
+	_ASM_EXTABLE_UA(5b, bad_get_user_8)
 #endif
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index 96dce5fe2a35..d2e5c9c39601 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -94,10 +94,10 @@  bad_put_user:
 	EXIT
 END(bad_put_user)
 
-	_ASM_EXTABLE(1b,bad_put_user)
-	_ASM_EXTABLE(2b,bad_put_user)
-	_ASM_EXTABLE(3b,bad_put_user)
-	_ASM_EXTABLE(4b,bad_put_user)
+	_ASM_EXTABLE_UA(1b, bad_put_user)
+	_ASM_EXTABLE_UA(2b, bad_put_user)
+	_ASM_EXTABLE_UA(3b, bad_put_user)
+	_ASM_EXTABLE_UA(4b, bad_put_user)
 #ifdef CONFIG_X86_32
-	_ASM_EXTABLE(5b,bad_put_user)
+	_ASM_EXTABLE_UA(5b, bad_put_user)
 #endif
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 7add8ba06887..71fb58d44d58 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -47,8 +47,8 @@  do {									\
 		"3:	lea 0(%2,%0,4),%0\n"				\
 		"	jmp 2b\n"					\
 		".previous\n"						\
-		_ASM_EXTABLE(0b,3b)					\
-		_ASM_EXTABLE(1b,2b)					\
+		_ASM_EXTABLE_UA(0b, 3b)					\
+		_ASM_EXTABLE_UA(1b, 2b)					\
 		: "=&c"(size), "=&D" (__d0)				\
 		: "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0));	\
 } while (0)
@@ -153,44 +153,44 @@  __copy_user_intel(void __user *to, const void *from, unsigned long size)
 		       "101:   lea 0(%%eax,%0,4),%0\n"
 		       "       jmp 100b\n"
 		       ".previous\n"
-		       _ASM_EXTABLE(1b,100b)
-		       _ASM_EXTABLE(2b,100b)
-		       _ASM_EXTABLE(3b,100b)
-		       _ASM_EXTABLE(4b,100b)
-		       _ASM_EXTABLE(5b,100b)
-		       _ASM_EXTABLE(6b,100b)
-		       _ASM_EXTABLE(7b,100b)
-		       _ASM_EXTABLE(8b,100b)
-		       _ASM_EXTABLE(9b,100b)
-		       _ASM_EXTABLE(10b,100b)
-		       _ASM_EXTABLE(11b,100b)
-		       _ASM_EXTABLE(12b,100b)
-		       _ASM_EXTABLE(13b,100b)
-		       _ASM_EXTABLE(14b,100b)
-		       _ASM_EXTABLE(15b,100b)
-		       _ASM_EXTABLE(16b,100b)
-		       _ASM_EXTABLE(17b,100b)
-		       _ASM_EXTABLE(18b,100b)
-		       _ASM_EXTABLE(19b,100b)
-		       _ASM_EXTABLE(20b,100b)
-		       _ASM_EXTABLE(21b,100b)
-		       _ASM_EXTABLE(22b,100b)
-		       _ASM_EXTABLE(23b,100b)
-		       _ASM_EXTABLE(24b,100b)
-		       _ASM_EXTABLE(25b,100b)
-		       _ASM_EXTABLE(26b,100b)
-		       _ASM_EXTABLE(27b,100b)
-		       _ASM_EXTABLE(28b,100b)
-		       _ASM_EXTABLE(29b,100b)
-		       _ASM_EXTABLE(30b,100b)
-		       _ASM_EXTABLE(31b,100b)
-		       _ASM_EXTABLE(32b,100b)
-		       _ASM_EXTABLE(33b,100b)
-		       _ASM_EXTABLE(34b,100b)
-		       _ASM_EXTABLE(35b,100b)
-		       _ASM_EXTABLE(36b,100b)
-		       _ASM_EXTABLE(37b,100b)
-		       _ASM_EXTABLE(99b,101b)
+		       _ASM_EXTABLE_UA(1b, 100b)
+		       _ASM_EXTABLE_UA(2b, 100b)
+		       _ASM_EXTABLE_UA(3b, 100b)
+		       _ASM_EXTABLE_UA(4b, 100b)
+		       _ASM_EXTABLE_UA(5b, 100b)
+		       _ASM_EXTABLE_UA(6b, 100b)
+		       _ASM_EXTABLE_UA(7b, 100b)
+		       _ASM_EXTABLE_UA(8b, 100b)
+		       _ASM_EXTABLE_UA(9b, 100b)
+		       _ASM_EXTABLE_UA(10b, 100b)
+		       _ASM_EXTABLE_UA(11b, 100b)
+		       _ASM_EXTABLE_UA(12b, 100b)
+		       _ASM_EXTABLE_UA(13b, 100b)
+		       _ASM_EXTABLE_UA(14b, 100b)
+		       _ASM_EXTABLE_UA(15b, 100b)
+		       _ASM_EXTABLE_UA(16b, 100b)
+		       _ASM_EXTABLE_UA(17b, 100b)
+		       _ASM_EXTABLE_UA(18b, 100b)
+		       _ASM_EXTABLE_UA(19b, 100b)
+		       _ASM_EXTABLE_UA(20b, 100b)
+		       _ASM_EXTABLE_UA(21b, 100b)
+		       _ASM_EXTABLE_UA(22b, 100b)
+		       _ASM_EXTABLE_UA(23b, 100b)
+		       _ASM_EXTABLE_UA(24b, 100b)
+		       _ASM_EXTABLE_UA(25b, 100b)
+		       _ASM_EXTABLE_UA(26b, 100b)
+		       _ASM_EXTABLE_UA(27b, 100b)
+		       _ASM_EXTABLE_UA(28b, 100b)
+		       _ASM_EXTABLE_UA(29b, 100b)
+		       _ASM_EXTABLE_UA(30b, 100b)
+		       _ASM_EXTABLE_UA(31b, 100b)
+		       _ASM_EXTABLE_UA(32b, 100b)
+		       _ASM_EXTABLE_UA(33b, 100b)
+		       _ASM_EXTABLE_UA(34b, 100b)
+		       _ASM_EXTABLE_UA(35b, 100b)
+		       _ASM_EXTABLE_UA(36b, 100b)
+		       _ASM_EXTABLE_UA(37b, 100b)
+		       _ASM_EXTABLE_UA(99b, 101b)
 		       : "=&c"(size), "=&D" (d0), "=&S" (d1)
 		       :  "1"(to), "2"(from), "0"(size)
 		       : "eax", "edx", "memory");
@@ -259,26 +259,26 @@  static unsigned long __copy_user_intel_nocache(void *to,
 	       "9:      lea 0(%%eax,%0,4),%0\n"
 	       "16:     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)
+	       _ASM_EXTABLE_UA(0b, 16b)
+	       _ASM_EXTABLE_UA(1b, 16b)
+	       _ASM_EXTABLE_UA(2b, 16b)
+	       _ASM_EXTABLE_UA(21b, 16b)
+	       _ASM_EXTABLE_UA(3b, 16b)
+	       _ASM_EXTABLE_UA(31b, 16b)
+	       _ASM_EXTABLE_UA(4b, 16b)
+	       _ASM_EXTABLE_UA(41b, 16b)
+	       _ASM_EXTABLE_UA(10b, 16b)
+	       _ASM_EXTABLE_UA(51b, 16b)
+	       _ASM_EXTABLE_UA(11b, 16b)
+	       _ASM_EXTABLE_UA(61b, 16b)
+	       _ASM_EXTABLE_UA(12b, 16b)
+	       _ASM_EXTABLE_UA(71b, 16b)
+	       _ASM_EXTABLE_UA(13b, 16b)
+	       _ASM_EXTABLE_UA(81b, 16b)
+	       _ASM_EXTABLE_UA(14b, 16b)
+	       _ASM_EXTABLE_UA(91b, 16b)
+	       _ASM_EXTABLE_UA(6b, 9b)
+	       _ASM_EXTABLE_UA(7b, 16b)
 	       : "=&c"(size), "=&D" (d0), "=&S" (d1)
 	       :  "1"(to), "2"(from), "0"(size)
 	       : "eax", "edx", "memory");
@@ -321,9 +321,9 @@  do {									\
 		"3:	lea 0(%3,%0,4),%0\n"				\
 		"	jmp 2b\n"					\
 		".previous\n"						\
-		_ASM_EXTABLE(4b,5b)					\
-		_ASM_EXTABLE(0b,3b)					\
-		_ASM_EXTABLE(1b,2b)					\
+		_ASM_EXTABLE_UA(4b, 5b)					\
+		_ASM_EXTABLE_UA(0b, 3b)					\
+		_ASM_EXTABLE_UA(1b, 2b)					\
 		: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2)	\
 		: "3"(size), "0"(size), "1"(to), "2"(from)		\
 		: "memory");						\
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 9c5606d88f61..fefe64436398 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -37,8 +37,8 @@  unsigned long __clear_user(void __user *addr, unsigned long size)
 		"3:	lea 0(%[size1],%[size8],8),%[size8]\n"
 		"	jmp 2b\n"
 		".previous\n"
-		_ASM_EXTABLE(0b,3b)
-		_ASM_EXTABLE(1b,2b)
+		_ASM_EXTABLE_UA(0b, 3b)
+		_ASM_EXTABLE_UA(1b, 2b)
 		: [size8] "=&c"(size), [dst] "=&D" (__d0)
 		: [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr));
 	clac();
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 45f5d6cf65ae..0b8b5d889eec 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -108,6 +108,14 @@  __visible bool ex_handler_fprestore(const struct exception_table_entry *fixup,
 }
 EXPORT_SYMBOL_GPL(ex_handler_fprestore);
 
+__visible bool ex_handler_uaccess(const struct exception_table_entry *fixup,
+				  struct pt_regs *regs, int trapnr)
+{
+	regs->ip = ex_fixup_addr(fixup);
+	return true;
+}
+EXPORT_SYMBOL(ex_handler_uaccess);
+
 __visible bool ex_handler_ext(const struct exception_table_entry *fixup,
 			      struct pt_regs *regs, int trapnr)
 {