MN10300: Extract the displacement from an insn correctly in misalignm…

…ent fixup

Extract the displacement from an MN10300 instruction correctly in the
misalignment fixup handler.

The code should extract the displacement in LSB order, not MSB order.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mn10300/mm/misalignment.c

@@ -43,11 +43,11 @@
 #endif
 
 static int misalignment_addr(unsigned long *registers, unsigned params,
-			     unsigned opcode, unsigned disp,
+			     unsigned opcode, unsigned long disp,
 			     void **_address, unsigned long **_postinc);
 
 static int misalignment_reg(unsigned long *registers, unsigned params,
-			    unsigned opcode, unsigned disp,
+			    unsigned opcode, unsigned long disp,
 			    unsigned long **_register);
 
 static const unsigned Dreg_index[] = {
@@ -304,13 +304,13 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code)
 	const struct exception_table_entry *fixup;
 	const struct mn10300_opcode *pop;
 	unsigned long *registers = (unsigned long *) regs;
-	unsigned long data, *store, *postinc;
+	unsigned long data, *store, *postinc, disp;
 	mm_segment_t seg;
 	siginfo_t info;
-	uint32_t opcode, disp, noc, xo, xm;
+	uint32_t opcode, noc, xo, xm;
 	uint8_t *pc, byte;
 	void *address;
-	unsigned tmp, npop;
+	unsigned tmp, npop, dispsz, loop;
 
 	kdebug("==>misalignment({pc=%lx})", regs->pc);
 
@@ -445,17 +445,17 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code)
 
 	/* grab the extra displacement (note it's LSB first) */
 	disp = 0;
-	tmp = format_tbl[pop->format].dispsz >> 3;
-	while (tmp > 0) {
-		tmp--;
-		disp <<= 8;
-
+	dispsz = format_tbl[pop->format].dispsz;
+	for (loop = 0; loop < dispsz; loop += 8) {
 		pc++;
 		if (__get_user(byte, pc) != 0)
 			goto fetch_error;
-		disp |= byte;
+		disp |= byte << loop;
+		kdebug("{%p} disp[%02x]=%02x", pc, loop, byte);
 	}
 
+	kdebug("disp=%lx", disp);
+
 	set_fs(KERNEL_XDS);
 	if (fixup || regs->epsw & EPSW_nSL)
 		set_fs(seg);
@@ -538,7 +538,7 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code)
  * determine the address that was being accessed
  */
 static int misalignment_addr(unsigned long *registers, unsigned params,
-			     unsigned opcode, unsigned disp,
+			     unsigned opcode, unsigned long disp,
 			     void **_address, unsigned long **_postinc)
 {
 	unsigned long *postinc = NULL, address = 0, tmp;
@@ -644,7 +644,7 @@ static int misalignment_addr(unsigned long *registers, unsigned params,
  * determine the register that is acting as source/dest
  */
 static int misalignment_reg(unsigned long *registers, unsigned params,
-			    unsigned opcode, unsigned disp,
+			    unsigned opcode, unsigned long disp,
 			    unsigned long **_register)
 {
 	params &= 0x7fffffff;