MIPS: bpf: Fix stack space allocation for BPF memwords on MIPS64

When allocating stack space for BPF memwords we need to use the
appropriate 32 or 64-bit instruction to avoid losing the top 32 bits
of the stack pointer.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7135/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/net/bpf_jit.c

@@ -623,7 +623,10 @@ static void save_bpf_jit_regs(struct jit_ctx *ctx, unsigned offset)
 	if (ctx->flags & SEEN_MEM) {
 		if (real_off % (RSIZE * 2))
 			real_off += RSIZE;
-		emit_addiu(r_M, r_sp, real_off, ctx);
+		if (config_enabled(CONFIG_64BIT))
+			emit_daddiu(r_M, r_sp, real_off, ctx);
+		else
+			emit_addiu(r_M, r_sp, real_off, ctx);
 	}
 }