[SPARC64]: Loosen checks in exception table handling.

Some parts of the kernel now do things like do *_user() accesses while
set_fs(KERNEL_DS) that fault on purpose.

See, for example, the code added by changeset
a0c1e90 ("futex: runtime enable pi
and robust functionality").

That trips up the ASI sanity checking we make in do_kernel_fault().

Just remove it for now.  Maybe we can add it back later with an added
conditional which looks at the current get_fs() value.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/mm/fault.c

@@ -244,16 +244,8 @@ static void do_kernel_fault(struct pt_regs *regs, int si_code, int fault_code,
 	if (regs->tstate & TSTATE_PRIV) {
 		const struct exception_table_entry *entry;
 
-		if (asi == ASI_P && (insn & 0xc0800000) == 0xc0800000) {
-			if (insn & 0x2000)
-				asi = (regs->tstate >> 24);
-			else
-				asi = (insn >> 5);
-		}
-
-		/* Look in asi.h: All _S asis have LS bit set */
-		if ((asi & 0x1) &&
-		    (entry = search_exception_tables(regs->tpc))) {
+		entry = search_exception_tables(regs->tpc);
+		if (entry) {
 			regs->tpc = entry->fixup;
 			regs->tnpc = regs->tpc + 4;
 			return;