1 files changed, 24 insertions, 13 deletions

diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index b820edaf318..b8cb1a2688a 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -25,8 +25,10 @@
 #include <asm/cp15.h>
 #include <asm/system_info.h>
 #include <asm/unaligned.h>
+#include <asm/opcodes.h>
 
 #include "fault.h"
+#include "mm.h"
 
 /*
  * 32-bit misaligned trap handler (c) 1998 San Mehat (CCC) -July 1998
@@ -80,6 +82,7 @@ static unsigned long ai_word;
 static unsigned long ai_dword;
 static unsigned long ai_multi;
 static int ai_usermode;
+static unsigned long cr_no_alignment;
 
 core_param(alignment, ai_usermode, int, 0600);
 
@@ -90,7 +93,7 @@ core_param(alignment, ai_usermode, int, 0600);
 /* Return true if and only if the ARMv6 unaligned access model is in use. */
 static bool cpu_is_v6_unaligned(void)
 {
-	return cpu_architecture() >= CPU_ARCH_ARMv6 && (cr_alignment & CR_U);
+	return cpu_architecture() >= CPU_ARCH_ARMv6 && get_cr() & CR_U;
 }
 
 static int safe_usermode(int new_usermode, bool warn)
@@ -749,7 +752,6 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	unsigned long instr = 0, instrptr;
 	int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs);
 	unsigned int type;
-	mm_segment_t fs;
 	unsigned int fault;
 	u16 tinstr = 0;
 	int isize = 4;
@@ -760,26 +762,28 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 
 	instrptr = instruction_pointer(regs);
 
-	fs = get_fs();
-	set_fs(KERNEL_DS);
 	if (thumb_mode(regs)) {
-		fault = __get_user(tinstr, (u16 *)(instrptr & ~1));
+		u16 *ptr = (u16 *)(instrptr & ~1);
+		fault = probe_kernel_address(ptr, tinstr);
+		tinstr = __mem_to_opcode_thumb16(tinstr);
 		if (!fault) {
 			if (cpu_architecture() >= CPU_ARCH_ARMv7 &&
 			    IS_T32(tinstr)) {
 				/* Thumb-2 32-bit */
 				u16 tinst2 = 0;
-				fault = __get_user(tinst2, (u16 *)(instrptr+2));
-				instr = (tinstr << 16) | tinst2;
+				fault = probe_kernel_address(ptr + 1, tinst2);
+				tinst2 = __mem_to_opcode_thumb16(tinst2);
+				instr = __opcode_thumb32_compose(tinstr, tinst2);
 				thumb2_32b = 1;
 			} else {
 				isize = 2;
 				instr = thumb2arm(tinstr);
 			}
 		}
-	} else
-		fault = __get_user(instr, (u32 *)instrptr);
-	set_fs(fs);
+	} else {
+		fault = probe_kernel_address(instrptr, instr);
+		instr = __mem_to_opcode_arm(instr);
+	}
 
 	if (fault) {
 		type = TYPE_FAULT;
@@ -947,6 +951,13 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	return 0;
 }
 
+static int __init noalign_setup(char *__unused)
+{
+	set_cr(__clear_cr(CR_A));
+	return 1;
+}
+__setup("noalign", noalign_setup);
+
 /*
  * This needs to be done after sysctl_init, otherwise sys/ will be
  * overwritten.  Actually, this shouldn't be in sys/ at all since
@@ -965,12 +976,12 @@ static int __init alignment_init(void)
 #endif
 
 	if (cpu_is_v6_unaligned()) {
-		cr_alignment &= ~CR_A;
-		cr_no_alignment &= ~CR_A;
-		set_cr(cr_alignment);
+		set_cr(__clear_cr(CR_A));
 		ai_usermode = safe_usermode(ai_usermode, false);
 	}
 
+	cr_no_alignment = get_cr() & ~CR_A;
+
 	hook_fault_code(FAULT_CODE_ALIGNMENT, do_alignment, SIGBUS, BUS_ADRALN,
 			"alignment exception");