[POWERPC] Fix handling of stfiwx math emulation



Its legal for the stfiwx instruction to have RA = 0 as part of its
effective address calculation.  This is illegal for all other XE
form instructions.

Add code to compute the proper effective address for stfiwx if
RA = 0 rather than treating it as illegal.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

parent 65a6ec0d

arch/powerpc/math-emu/math.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -407,11 +407,16 @@ do_mathemu(struct pt_regs *regs)

		case XE:
		idx = (insn >> 16) & 0x1f;
		if (!idx)
		goto illegal;

		op0 = (void *)&current->thread.fpr[(insn >> 21) & 0x1f];
		if (!idx) {
		if (((insn >> 1) & 0x3ff) == STFIWX)
		op1 = (void *)(regs->gpr[(insn >> 11) & 0x1f]);
		else
		goto illegal;
		} else {
		op1 = (void *)(regs->gpr[idx] + regs->gpr[(insn >> 11) & 0x1f]);
		}

		break;

		case XEU: