x86, extable: Add _ASM_EXTABLE_EX() macro
Add _ASM_EXTABLE_EX() to generate the special extable entries that are
associated with uaccess_err. This allows us to change the protocol
associated with these special entries.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/CA%2B55aFyijf43qSu3N9nWHEBwaGbb7T2Oq9A=9EyR=Jtyqfq_cQ@mail.gmail.com
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 53dce41..0f15e8a 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -40,16 +40,28 @@
/* Exception table entry */
#ifdef __ASSEMBLY__
-# define _ASM_EXTABLE(from,to) \
- .pushsection "__ex_table","a" ; \
- _ASM_ALIGN ; \
- _ASM_PTR from , to ; \
+# define _ASM_EXTABLE(from,to) \
+ .pushsection "__ex_table","a" ; \
+ _ASM_ALIGN ; \
+ _ASM_PTR from , to ; \
+ .popsection
+
+# define _ASM_EXTABLE_EX(from,to) \
+ .pushsection "__ex_table","a" ; \
+ _ASM_ALIGN ; \
+ _ASM_PTR from , (to) - (from) ; \
.popsection
#else
-# define _ASM_EXTABLE(from,to) \
- " .pushsection \"__ex_table\",\"a\"\n" \
- _ASM_ALIGN "\n" \
- _ASM_PTR #from "," #to "\n" \
+# define _ASM_EXTABLE(from,to) \
+ " .pushsection \"__ex_table\",\"a\"\n" \
+ _ASM_ALIGN "\n" \
+ _ASM_PTR #from "," #to "\n" \
+ " .popsection\n"
+
+# define _ASM_EXTABLE_EX(from,to) \
+ " .pushsection \"__ex_table\",\"a\"\n" \
+ _ASM_ALIGN "\n" \
+ _ASM_PTR #from ",(" #to ")-(" #from ")\n" \
" .popsection\n"
#endif
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index e054459..4ee59dd 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -202,8 +202,8 @@
asm volatile("1: movl %%eax,0(%1)\n" \
"2: movl %%edx,4(%1)\n" \
"3:\n" \
- _ASM_EXTABLE(1b, 2b - 1b) \
- _ASM_EXTABLE(2b, 3b - 2b) \
+ _ASM_EXTABLE_EX(1b, 2b) \
+ _ASM_EXTABLE_EX(2b, 3b) \
: : "A" (x), "r" (addr))
#define __put_user_x8(x, ptr, __ret_pu) \
@@ -408,7 +408,7 @@
#define __get_user_asm_ex(x, addr, itype, rtype, ltype) \
asm volatile("1: mov"itype" %1,%"rtype"0\n" \
"2:\n" \
- _ASM_EXTABLE(1b, 2b - 1b) \
+ _ASM_EXTABLE_EX(1b, 2b) \
: ltype(x) : "m" (__m(addr)))
#define __put_user_nocheck(x, ptr, size) \
@@ -450,7 +450,7 @@
#define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
asm volatile("1: mov"itype" %"rtype"0,%1\n" \
"2:\n" \
- _ASM_EXTABLE(1b, 2b - 1b) \
+ _ASM_EXTABLE_EX(1b, 2b) \
: : ltype(x), "m" (__m(addr)))
/*