s390/bpf: Fix ALU_NEG (A = -A)

Currently the LOAD NEGATIVE (lnr) instruction is used for ALU_NEG. This
instruction always loads the negative value. Therefore, if A is already
negative, it remains unchanged. To fix this use LOAD COMPLEMENT (lcr)
instead.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index c52ac77408ca..8bc474fb52fd 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -431,8 +431,8 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
                 EMIT4_DISP(0x88500000, K);
                 break;
         case BPF_ALU | BPF_NEG: /* A = -A */
-                /* lnr %r5,%r5 */
-                EMIT2(0x1155);
+                /* lcr %r5,%r5 */
+                EMIT2(0x1355);
                 break;
         case BPF_JMP | BPF_JA: /* ip += K */
                 offset = addrs[i + K] + jit->start - jit->prg;