1 files changed, 34 insertions, 7 deletions

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 5e7c63033159..e636728ab452 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -299,9 +299,11 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
 
 #define EMIT_ZERO(b1)                                           \
 ({                                                              \
-        /* llgfr %dst,%dst (zero extend to 64 bit) */           \
-        EMIT4(0xb9160000, b1, b1);                              \
-        REG_SET_SEEN(b1);                                       \
+        if (!fp->aux->verifier_zext) {                          \
+                /* llgfr %dst,%dst (zero extend to 64 bit) */   \
+                EMIT4(0xb9160000, b1, b1);                      \
+                REG_SET_SEEN(b1);                               \
+        }                                                       \
 })
 
 /*
@@ -520,6 +522,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
         case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
                 /* llgfr %dst,%src */
                 EMIT4(0xb9160000, dst_reg, src_reg);
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
                 /* lgr %dst,%src */
@@ -528,6 +532,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
         case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
                 /* llilf %dst,imm */
                 EMIT6_IMM(0xc00f0000, dst_reg, imm);
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
                 /* lgfi %dst,imm */
@@ -639,6 +645,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
                 EMIT4(0xb9970000, REG_W0, src_reg);
                 /* llgfr %dst,%rc */
                 EMIT4(0xb9160000, dst_reg, rc_reg);
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         }
         case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
@@ -676,6 +684,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
                               EMIT_CONST_U32(imm));
                 /* llgfr %dst,%rc */
                 EMIT4(0xb9160000, dst_reg, rc_reg);
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         }
         case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
@@ -864,10 +874,13 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
                 case 16: /* dst = (u16) cpu_to_be16(dst) */
                         /* llghr %dst,%dst */
                         EMIT4(0xb9850000, dst_reg, dst_reg);
+                        if (insn_is_zext(&insn[1]))
+                                insn_count = 2;
                         break;
                 case 32: /* dst = (u32) cpu_to_be32(dst) */
-                        /* llgfr %dst,%dst */
-                        EMIT4(0xb9160000, dst_reg, dst_reg);
+                        if (!fp->aux->verifier_zext)
+                                /* llgfr %dst,%dst */
+                                EMIT4(0xb9160000, dst_reg, dst_reg);
                         break;
                 case 64: /* dst = (u64) cpu_to_be64(dst) */
                         break;
@@ -882,12 +895,15 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
                         EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
                         /* llghr %dst,%dst */
                         EMIT4(0xb9850000, dst_reg, dst_reg);
+                        if (insn_is_zext(&insn[1]))
+                                insn_count = 2;
                         break;
                 case 32: /* dst = (u32) cpu_to_le32(dst) */
                         /* lrvr %dst,%dst */
                         EMIT4(0xb91f0000, dst_reg, dst_reg);
-                        /* llgfr %dst,%dst */
-                        EMIT4(0xb9160000, dst_reg, dst_reg);
+                        if (!fp->aux->verifier_zext)
+                                /* llgfr %dst,%dst */
+                                EMIT4(0xb9160000, dst_reg, dst_reg);
                         break;
                 case 64: /* dst = (u64) cpu_to_le64(dst) */
                         /* lrvgr %dst,%dst */
@@ -968,16 +984,22 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
                 /* llgc %dst,0(off,%src) */
                 EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
                 jit->seen |= SEEN_MEM;
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
                 /* llgh %dst,0(off,%src) */
                 EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
                 jit->seen |= SEEN_MEM;
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
                 /* llgf %dst,off(%src) */
                 jit->seen |= SEEN_MEM;
                 EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
+                if (insn_is_zext(&insn[1]))
+                        insn_count = 2;
                 break;
         case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
                 /* lg %dst,0(off,%src) */
@@ -1282,6 +1304,11 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
         return 0;
 }
 
+bool bpf_jit_needs_zext(void)
+{
+        return true;
+}
+
 /*
  * Compile eBPF program "fp"
  */