From: Jiong Wang <jiong.wang@netronome.com>
Date: Thu, 30 Nov 2017 21:32:55 -0800
Subject: nfp: bpf: correct the encoding for No-Dest immed
Patch-mainline: v4.16-rc1
Git-commit: 3239e7bb28a8a4a96c36beeaa6439666e1ed4f8b
References: bsc#1109837

When immed is used with No-Dest, the emitter should use reg.dst instead of
reg.areg for the destination, using the latter will actually encode
register zero.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -224,9 +224,11 @@ emit_immed(struct nfp_prog *nfp_prog, sw
 		return;
 	}
 
-	__emit_immed(nfp_prog, reg.areg, reg.breg, imm >> 8, width,
-		     invert, shift, reg.wr_both,
-		     reg.dst_lmextn, reg.src_lmextn);
+	/* Use reg.dst when destination is No-Dest. */
+	__emit_immed(nfp_prog,
+		     swreg_type(dst) == NN_REG_NONE ? reg.dst : reg.areg,
+		     reg.breg, imm >> 8, width, invert, shift,
+		     reg.wr_both, reg.dst_lmextn, reg.src_lmextn);
 }
 
 static void