s390/bpf: fix bpf frame pointer setup

[karo-tx-linux.git] / arch / s390 / net / bpf_jit_comp.c

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 20c146d1251ae2cd6c07279bf371adae6b2e3a1e..55423d8be580113d045d30edbf86d26fb74340ff 100644 (file)
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -384,13 +384,16 @@ static void bpf_jit_prologue(struct bpf_jit *jit)
        }
        /* Setup stack and backchain */
        if (jit->seen & SEEN_STACK) {
-               /* lgr %bfp,%r15 (BPF frame pointer) */
-               EMIT4(0xb9040000, BPF_REG_FP, REG_15);
+               if (jit->seen & SEEN_FUNC)
+                       /* lgr %w1,%r15 (backchain) */
+                       EMIT4(0xb9040000, REG_W1, REG_15);
+               /* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
+               EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
                /* aghi %r15,-STK_OFF */
                EMIT4_IMM(0xa70b0000, REG_15, -STK_OFF);
                if (jit->seen & SEEN_FUNC)
-                       /* stg %bfp,152(%r15) (backchain) */
-                       EMIT6_DISP_LH(0xe3000000, 0x0024, BPF_REG_FP, REG_0,
+                       /* stg %w1,152(%r15) (backchain) */
+                       EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
                                      REG_15, 152);
        }
        /*