]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - arch/s390/net/bpf_jit_comp.c
s390/bpf: Fix gcov stack space problem
[karo-tx-linux.git] / arch / s390 / net / bpf_jit_comp.c
index bbd1981cc15007fcdb779ca201553ed28012f20d..20c146d1251ae2cd6c07279bf371adae6b2e3a1e 100644 (file)
 /*
  * BPF Jit compiler for s390.
  *
- * Copyright IBM Corp. 2012
+ * Minimum build requirements:
+ *
+ *  - HAVE_MARCH_Z196_FEATURES: laal, laalg
+ *  - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj
+ *  - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf
+ *  - PACK_STACK
+ *  - 64BIT
+ *
+ * Copyright IBM Corp. 2012,2015
  *
  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *           Michael Holzheu <holzheu@linux.vnet.ibm.com>
  */
+
+#define KMSG_COMPONENT "bpf_jit"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/netdevice.h>
-#include <linux/if_vlan.h>
 #include <linux/filter.h>
 #include <linux/init.h>
 #include <asm/cacheflush.h>
-#include <asm/facility.h>
 #include <asm/dis.h>
+#include "bpf_jit.h"
 
-/*
- * Conventions:
- *   %r2 = skb pointer
- *   %r3 = offset parameter
- *   %r4 = scratch register / length parameter
- *   %r5 = BPF A accumulator
- *   %r8 = return address
- *   %r9 = save register for skb pointer
- *   %r10 = skb->data
- *   %r11 = skb->len - skb->data_len (headlen)
- *   %r12 = BPF X accumulator
- *   %r13 = literal pool pointer
- *   0(%r15) - 63(%r15) scratch memory array with BPF_MEMWORDS
- */
 int bpf_jit_enable __read_mostly;
 
+struct bpf_jit {
+       u32 seen;               /* Flags to remember seen eBPF instructions */
+       u32 seen_reg[16];       /* Array to remember which registers are used */
+       u32 *addrs;             /* Array with relative instruction addresses */
+       u8 *prg_buf;            /* Start of program */
+       int size;               /* Size of program and literal pool */
+       int size_prg;           /* Size of program */
+       int prg;                /* Current position in program */
+       int lit_start;          /* Start of literal pool */
+       int lit;                /* Current position in literal pool */
+       int base_ip;            /* Base address for literal pool */
+       int ret0_ip;            /* Address of return 0 */
+       int exit_ip;            /* Address of exit */
+};
+
+#define BPF_SIZE_MAX   4096    /* Max size for program */
+
+#define SEEN_SKB       1       /* skb access */
+#define SEEN_MEM       2       /* use mem[] for temporary storage */
+#define SEEN_RET0      4       /* ret0_ip points to a valid return 0 */
+#define SEEN_LITERAL   8       /* code uses literals */
+#define SEEN_FUNC      16      /* calls C functions */
+#define SEEN_STACK     (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
+
 /*
- * assembly code in arch/x86/net/bpf_jit.S
+ * s390 registers
  */
-extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
-extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[];
+#define REG_W0         (__MAX_BPF_REG+0)       /* Work register 1 (even) */
+#define REG_W1         (__MAX_BPF_REG+1)       /* Work register 2 (odd) */
+#define REG_SKB_DATA   (__MAX_BPF_REG+2)       /* SKB data register */
+#define REG_L          (__MAX_BPF_REG+3)       /* Literal pool register */
+#define REG_15         (__MAX_BPF_REG+4)       /* Register 15 */
+#define REG_0          REG_W0                  /* Register 0 */
+#define REG_2          BPF_REG_1               /* Register 2 */
+#define REG_14         BPF_REG_0               /* Register 14 */
 
-struct bpf_jit {
-       unsigned int seen;
-       u8 *start;
-       u8 *prg;
-       u8 *mid;
-       u8 *lit;
-       u8 *end;
-       u8 *base_ip;
-       u8 *ret0_ip;
-       u8 *exit_ip;
-       unsigned int off_load_word;
-       unsigned int off_load_half;
-       unsigned int off_load_byte;
-       unsigned int off_load_bmsh;
-       unsigned int off_load_iword;
-       unsigned int off_load_ihalf;
-       unsigned int off_load_ibyte;
+/*
+ * Mapping of BPF registers to s390 registers
+ */
+static const int reg2hex[] = {
+       /* Return code */
+       [BPF_REG_0]     = 14,
+       /* Function parameters */
+       [BPF_REG_1]     = 2,
+       [BPF_REG_2]     = 3,
+       [BPF_REG_3]     = 4,
+       [BPF_REG_4]     = 5,
+       [BPF_REG_5]     = 6,
+       /* Call saved registers */
+       [BPF_REG_6]     = 7,
+       [BPF_REG_7]     = 8,
+       [BPF_REG_8]     = 9,
+       [BPF_REG_9]     = 10,
+       /* BPF stack pointer */
+       [BPF_REG_FP]    = 13,
+       /* SKB data pointer */
+       [REG_SKB_DATA]  = 12,
+       /* Work registers for s390x backend */
+       [REG_W0]        = 0,
+       [REG_W1]        = 1,
+       [REG_L]         = 11,
+       [REG_15]        = 15,
 };
 
-#define BPF_SIZE_MAX   4096    /* Max size for program */
+static inline u32 reg(u32 dst_reg, u32 src_reg)
+{
+       return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
+}
+
+static inline u32 reg_high(u32 reg)
+{
+       return reg2hex[reg] << 4;
+}
+
+static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
+{
+       u32 r1 = reg2hex[b1];
+
+       if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
+               jit->seen_reg[r1] = 1;
+}
+
+#define REG_SET_SEEN(b1)                                       \
+({                                                             \
+       reg_set_seen(jit, b1);                                  \
+})
+
+#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
+
+/*
+ * EMIT macros for code generation
+ */
+
+#define _EMIT2(op)                                             \
+({                                                             \
+       if (jit->prg_buf)                                       \
+               *(u16 *) (jit->prg_buf + jit->prg) = op;        \
+       jit->prg += 2;                                          \
+})
 
-#define SEEN_DATAREF   1       /* might call external helpers */
-#define SEEN_XREG      2       /* ebx is used */
-#define SEEN_MEM       4       /* use mem[] for temporary storage */
-#define SEEN_RET0      8       /* pc_ret0 points to a valid return 0 */
-#define SEEN_LITERAL   16      /* code uses literals */
-#define SEEN_LOAD_WORD 32      /* code uses sk_load_word */
-#define SEEN_LOAD_HALF 64      /* code uses sk_load_half */
-#define SEEN_LOAD_BYTE 128     /* code uses sk_load_byte */
-#define SEEN_LOAD_BMSH 256     /* code uses sk_load_byte_msh */
-#define SEEN_LOAD_IWORD        512     /* code uses sk_load_word_ind */
-#define SEEN_LOAD_IHALF        1024    /* code uses sk_load_half_ind */
-#define SEEN_LOAD_IBYTE        2048    /* code uses sk_load_byte_ind */
-
-#define EMIT2(op)                                      \
-({                                                     \
-       if (jit->prg + 2 <= jit->mid)                   \
-               *(u16 *) jit->prg = op;                 \
-       jit->prg += 2;                                  \
+#define EMIT2(op, b1, b2)                                      \
+({                                                             \
+       _EMIT2(op | reg(b1, b2));                               \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
 })
 
-#define EMIT4(op)                                      \
-({                                                     \
-       if (jit->prg + 4 <= jit->mid)                   \
-               *(u32 *) jit->prg = op;                 \
-       jit->prg += 4;                                  \
+#define _EMIT4(op)                                             \
+({                                                             \
+       if (jit->prg_buf)                                       \
+               *(u32 *) (jit->prg_buf + jit->prg) = op;        \
+       jit->prg += 4;                                          \
 })
 
-#define EMIT4_DISP(op, disp)                           \
-({                                                     \
-       unsigned int __disp = (disp) & 0xfff;           \
-       EMIT4(op | __disp);                             \
+#define EMIT4(op, b1, b2)                                      \
+({                                                             \
+       _EMIT4(op | reg(b1, b2));                               \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
 })
 
-#define EMIT4_IMM(op, imm)                             \
-({                                                     \
-       unsigned int __imm = (imm) & 0xffff;            \
-       EMIT4(op | __imm);                              \
+#define EMIT4_RRF(op, b1, b2, b3)                              \
+({                                                             \
+       _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2));           \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
+       REG_SET_SEEN(b3);                                       \
 })
 
-#define EMIT4_PCREL(op, pcrel)                         \
-({                                                     \
-       long __pcrel = ((pcrel) >> 1) & 0xffff;         \
-       EMIT4(op | __pcrel);                            \
+#define _EMIT4_DISP(op, disp)                                  \
+({                                                             \
+       unsigned int __disp = (disp) & 0xfff;                   \
+       _EMIT4(op | __disp);                                    \
 })
 
-#define EMIT6(op1, op2)                                        \
-({                                                     \
-       if (jit->prg + 6 <= jit->mid) {                 \
-               *(u32 *) jit->prg = op1;                \
-               *(u16 *) (jit->prg + 4) = op2;          \
-       }                                               \
-       jit->prg += 6;                                  \
+#define EMIT4_DISP(op, b1, b2, disp)                           \
+({                                                             \
+       _EMIT4_DISP(op | reg_high(b1) << 16 |                   \
+                   reg_high(b2) << 8, disp);                   \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
 })
 
-#define EMIT6_DISP(op1, op2, disp)                     \
-({                                                     \
-       unsigned int __disp = (disp) & 0xfff;           \
-       EMIT6(op1 | __disp, op2);                       \
+#define EMIT4_IMM(op, b1, imm)                                 \
+({                                                             \
+       unsigned int __imm = (imm) & 0xffff;                    \
+       _EMIT4(op | reg_high(b1) << 16 | __imm);                \
+       REG_SET_SEEN(b1);                                       \
 })
 
-#define EMIT6_IMM(op, imm)                             \
-({                                                     \
-       unsigned int __imm = (imm);                     \
-       EMIT6(op | (__imm >> 16), __imm & 0xffff);      \
+#define EMIT4_PCREL(op, pcrel)                                 \
+({                                                             \
+       long __pcrel = ((pcrel) >> 1) & 0xffff;                 \
+       _EMIT4(op | __pcrel);                                   \
 })
 
-#define EMIT_CONST(val)                                        \
-({                                                     \
-       unsigned int ret;                               \
-       ret = (unsigned int) (jit->lit - jit->base_ip); \
-       jit->seen |= SEEN_LITERAL;                      \
-       if (jit->lit + 4 <= jit->end)                   \
-               *(u32 *) jit->lit = val;                \
-       jit->lit += 4;                                  \
-       ret;                                            \
+#define _EMIT6(op1, op2)                                       \
+({                                                             \
+       if (jit->prg_buf) {                                     \
+               *(u32 *) (jit->prg_buf + jit->prg) = op1;       \
+               *(u16 *) (jit->prg_buf + jit->prg + 4) = op2;   \
+       }                                                       \
+       jit->prg += 6;                                          \
 })
 
-#define EMIT_FN_CONST(bit, fn)                         \
-({                                                     \
-       unsigned int ret;                               \
-       ret = (unsigned int) (jit->lit - jit->base_ip); \
-       if (jit->seen & bit) {                          \
-               jit->seen |= SEEN_LITERAL;              \
-               if (jit->lit + 8 <= jit->end)           \
-                       *(void **) jit->lit = fn;       \
-               jit->lit += 8;                          \
-       }                                               \
-       ret;                                            \
+#define _EMIT6_DISP(op1, op2, disp)                            \
+({                                                             \
+       unsigned int __disp = (disp) & 0xfff;                   \
+       _EMIT6(op1 | __disp, op2);                              \
 })
 
-static void bpf_jit_fill_hole(void *area, unsigned int size)
+#define EMIT6_DISP(op1, op2, b1, b2, b3, disp)                 \
+({                                                             \
+       _EMIT6_DISP(op1 | reg(b1, b2) << 16 |                   \
+                   reg_high(b3) << 8, op2, disp);              \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
+       REG_SET_SEEN(b3);                                       \
+})
+
+#define _EMIT6_DISP_LH(op1, op2, disp)                         \
+({                                                             \
+       unsigned int __disp_h = ((u32)disp) & 0xff000;          \
+       unsigned int __disp_l = ((u32)disp) & 0x00fff;          \
+       _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4);            \
+})
+
+#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp)              \
+({                                                             \
+       _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 |                \
+                      reg_high(b3) << 8, op2, disp);           \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
+       REG_SET_SEEN(b3);                                       \
+})
+
+#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask)            \
+({                                                             \
+       /* Branch instruction needs 6 bytes */                  \
+       int rel = (addrs[i + off + 1] - (addrs[i + 1] - 6)) / 2;\
+       _EMIT6(op1 | reg(b1, b2) << 16 | rel, op2 | mask);      \
+       REG_SET_SEEN(b1);                                       \
+       REG_SET_SEEN(b2);                                       \
+})
+
+#define _EMIT6_IMM(op, imm)                                    \
+({                                                             \
+       unsigned int __imm = (imm);                             \
+       _EMIT6(op | (__imm >> 16), __imm & 0xffff);             \
+})
+
+#define EMIT6_IMM(op, b1, imm)                                 \
+({                                                             \
+       _EMIT6_IMM(op | reg_high(b1) << 16, imm);               \
+       REG_SET_SEEN(b1);                                       \
+})
+
+#define EMIT_CONST_U32(val)                                    \
+({                                                             \
+       unsigned int ret;                                       \
+       ret = jit->lit - jit->base_ip;                          \
+       jit->seen |= SEEN_LITERAL;                              \
+       if (jit->prg_buf)                                       \
+               *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
+       jit->lit += 4;                                          \
+       ret;                                                    \
+})
+
+#define EMIT_CONST_U64(val)                                    \
+({                                                             \
+       unsigned int ret;                                       \
+       ret = jit->lit - jit->base_ip;                          \
+       jit->seen |= SEEN_LITERAL;                              \
+       if (jit->prg_buf)                                       \
+               *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
+       jit->lit += 8;                                          \
+       ret;                                                    \
+})
+
+#define EMIT_ZERO(b1)                                          \
+({                                                             \
+       /* llgfr %dst,%dst (zero extend to 64 bit) */           \
+       EMIT4(0xb9160000, b1, b1);                              \
+       REG_SET_SEEN(b1);                                       \
+})
+
+/*
+ * Fill whole space with illegal instructions
+ */
+static void jit_fill_hole(void *area, unsigned int size)
 {
-       /* Fill whole space with illegal instructions */
        memset(area, 0, size);
 }
 
-static void bpf_jit_prologue(struct bpf_jit *jit)
+/*
+ * Save registers from "rs" (register start) to "re" (register end) on stack
+ */
+static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
+{
+       u32 off = 72 + (rs - 6) * 8;
+
+       if (rs == re)
+               /* stg %rs,off(%r15) */
+               _EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
+       else
+               /* stmg %rs,%re,off(%r15) */
+               _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
+}
+
+/*
+ * Restore registers from "rs" (register start) to "re" (register end) on stack
+ */
+static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re)
+{
+       u32 off = 72 + (rs - 6) * 8;
+
+       if (jit->seen & SEEN_STACK)
+               off += STK_OFF;
+
+       if (rs == re)
+               /* lg %rs,off(%r15) */
+               _EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
+       else
+               /* lmg %rs,%re,off(%r15) */
+               _EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
+}
+
+/*
+ * Return first seen register (from start)
+ */
+static int get_start(struct bpf_jit *jit, int start)
 {
-       /* Save registers and create stack frame if necessary */
-       if (jit->seen & SEEN_DATAREF) {
-               /* stmg %r8,%r15,88(%r15) */
-               EMIT6(0xeb8ff058, 0x0024);
-               /* lgr %r14,%r15 */
-               EMIT4(0xb90400ef);
-               /* aghi %r15,<offset> */
-               EMIT4_IMM(0xa7fb0000, (jit->seen & SEEN_MEM) ? -112 : -80);
-               /* stg %r14,152(%r15) */
-               EMIT6(0xe3e0f098, 0x0024);
-       } else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
-               /* stmg %r12,%r13,120(%r15) */
-               EMIT6(0xebcdf078, 0x0024);
-       else if (jit->seen & SEEN_XREG)
-               /* stg %r12,120(%r15) */
-               EMIT6(0xe3c0f078, 0x0024);
-       else if (jit->seen & SEEN_LITERAL)
-               /* stg %r13,128(%r15) */
-               EMIT6(0xe3d0f080, 0x0024);
+       int i;
 
+       for (i = start; i <= 15; i++) {
+               if (jit->seen_reg[i])
+                       return i;
+       }
+       return 0;
+}
+
+/*
+ * Return last seen register (from start) (gap >= 2)
+ */
+static int get_end(struct bpf_jit *jit, int start)
+{
+       int i;
+
+       for (i = start; i < 15; i++) {
+               if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
+                       return i - 1;
+       }
+       return jit->seen_reg[15] ? 15 : 14;
+}
+
+#define REGS_SAVE      1
+#define REGS_RESTORE   0
+/*
+ * Save and restore clobbered registers (6-15) on stack.
+ * We save/restore registers in chunks with gap >= 2 registers.
+ */
+static void save_restore_regs(struct bpf_jit *jit, int op)
+{
+
+       int re = 6, rs;
+
+       do {
+               rs = get_start(jit, re);
+               if (!rs)
+                       break;
+               re = get_end(jit, rs + 1);
+               if (op == REGS_SAVE)
+                       save_regs(jit, rs, re);
+               else
+                       restore_regs(jit, rs, re);
+               re++;
+       } while (re <= 15);
+}
+
+/*
+ * Emit function prologue
+ *
+ * Save registers and create stack frame if necessary.
+ * See stack frame layout desription in "bpf_jit.h"!
+ */
+static void bpf_jit_prologue(struct bpf_jit *jit)
+{
+       /* Save registers */
+       save_restore_regs(jit, REGS_SAVE);
        /* Setup literal pool */
        if (jit->seen & SEEN_LITERAL) {
                /* basr %r13,0 */
-               EMIT2(0x0dd0);
+               EMIT2(0x0d00, REG_L, REG_0);
                jit->base_ip = jit->prg;
        }
-       jit->off_load_word = EMIT_FN_CONST(SEEN_LOAD_WORD, sk_load_word);
-       jit->off_load_half = EMIT_FN_CONST(SEEN_LOAD_HALF, sk_load_half);
-       jit->off_load_byte = EMIT_FN_CONST(SEEN_LOAD_BYTE, sk_load_byte);
-       jit->off_load_bmsh = EMIT_FN_CONST(SEEN_LOAD_BMSH, sk_load_byte_msh);
-       jit->off_load_iword = EMIT_FN_CONST(SEEN_LOAD_IWORD, sk_load_word_ind);
-       jit->off_load_ihalf = EMIT_FN_CONST(SEEN_LOAD_IHALF, sk_load_half_ind);
-       jit->off_load_ibyte = EMIT_FN_CONST(SEEN_LOAD_IBYTE, sk_load_byte_ind);
-
-       /* Filter needs to access skb data */
-       if (jit->seen & SEEN_DATAREF) {
-               /* l %r11,<len>(%r2) */
-               EMIT4_DISP(0x58b02000, offsetof(struct sk_buff, len));
-               /* s %r11,<data_len>(%r2) */
-               EMIT4_DISP(0x5bb02000, offsetof(struct sk_buff, data_len));
-               /* lg %r10,<data>(%r2) */
-               EMIT6_DISP(0xe3a02000, 0x0004,
-                          offsetof(struct sk_buff, data));
+       /* Setup stack and backchain */
+       if (jit->seen & SEEN_STACK) {
+               /* lgr %bfp,%r15 (BPF frame pointer) */
+               EMIT4(0xb9040000, BPF_REG_FP, REG_15);
+               /* 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,
+                                     REG_15, 152);
        }
+       /*
+        * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
+        * we store the SKB header length on the stack and the SKB data
+        * pointer in REG_SKB_DATA.
+        */
+       if (jit->seen & SEEN_SKB) {
+               /* Header length: llgf %w1,<len>(%b1) */
+               EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
+                             offsetof(struct sk_buff, len));
+               /* s %w1,<data_len>(%b1) */
+               EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
+                          offsetof(struct sk_buff, data_len));
+               /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
+               EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15,
+                             STK_OFF_HLEN);
+               /* lg %skb_data,data_off(%b1) */
+               EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
+                             BPF_REG_1, offsetof(struct sk_buff, data));
+       }
+       /* BPF compatibility: clear A (%b7) and X (%b8) registers */
+       if (REG_SEEN(BPF_REG_7))
+               /* lghi %b7,0 */
+               EMIT4_IMM(0xa7090000, BPF_REG_7, 0);
+       if (REG_SEEN(BPF_REG_8))
+               /* lghi %b8,0 */
+               EMIT4_IMM(0xa7090000, BPF_REG_8, 0);
 }
 
+/*
+ * Function epilogue
+ */
 static void bpf_jit_epilogue(struct bpf_jit *jit)
 {
        /* Return 0 */
        if (jit->seen & SEEN_RET0) {
                jit->ret0_ip = jit->prg;
-               /* lghi %r2,0 */
-               EMIT4(0xa7290000);
+               /* lghi %b0,0 */
+               EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
        }
        jit->exit_ip = jit->prg;
+       /* Load exit code: lgr %r2,%b0 */
+       EMIT4(0xb9040000, REG_2, BPF_REG_0);
        /* Restore registers */
-       if (jit->seen & SEEN_DATAREF)
-               /* lmg %r8,%r15,<offset>(%r15) */
-               EMIT6_DISP(0xeb8ff000, 0x0004,
-                          (jit->seen & SEEN_MEM) ? 200 : 168);
-       else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
-               /* lmg %r12,%r13,120(%r15) */
-               EMIT6(0xebcdf078, 0x0004);
-       else if (jit->seen & SEEN_XREG)
-               /* lg %r12,120(%r15) */
-               EMIT6(0xe3c0f078, 0x0004);
-       else if (jit->seen & SEEN_LITERAL)
-               /* lg %r13,128(%r15) */
-               EMIT6(0xe3d0f080, 0x0004);
+       save_restore_regs(jit, REGS_RESTORE);
        /* br %r14 */
-       EMIT2(0x07fe);
+       _EMIT2(0x07fe);
 }
 
 /*
- * make sure we dont leak kernel information to user
+ * Compile one eBPF instruction into s390x code
+ *
+ * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
+ * stack space for the large switch statement.
  */
-static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
+static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i)
 {
-       /* Clear temporary memory if (seen & SEEN_MEM) */
-       if (jit->seen & SEEN_MEM)
-               /* xc 0(64,%r15),0(%r15) */
-               EMIT6(0xd73ff000, 0xf000);
-       /* Clear X if (seen & SEEN_XREG) */
-       if (jit->seen & SEEN_XREG)
-               /* lhi %r12,0 */
-               EMIT4(0xa7c80000);
-       /* Clear A if the first register does not set it. */
-       switch (filter[0].code) {
-       case BPF_LD | BPF_W | BPF_ABS:
-       case BPF_LD | BPF_H | BPF_ABS:
-       case BPF_LD | BPF_B | BPF_ABS:
-       case BPF_LD | BPF_W | BPF_LEN:
-       case BPF_LD | BPF_W | BPF_IND:
-       case BPF_LD | BPF_H | BPF_IND:
-       case BPF_LD | BPF_B | BPF_IND:
-       case BPF_LD | BPF_IMM:
-       case BPF_LD | BPF_MEM:
-       case BPF_MISC | BPF_TXA:
-       case BPF_RET | BPF_K:
-               /* first instruction sets A register */
-               break;
-       default: /* A = 0 */
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-       }
-}
+       struct bpf_insn *insn = &fp->insnsi[i];
+       int jmp_off, last, insn_count = 1;
+       unsigned int func_addr, mask;
+       u32 dst_reg = insn->dst_reg;
+       u32 src_reg = insn->src_reg;
+       u32 *addrs = jit->addrs;
+       s32 imm = insn->imm;
+       s16 off = insn->off;
 
-static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
-                       unsigned int *addrs, int i, int last)
-{
-       unsigned int K;
-       int offset;
-       unsigned int mask;
-       u16 code;
-
-       K = filter->k;
-       code = bpf_anc_helper(filter);
-
-       switch (code) {
-       case BPF_ALU | BPF_ADD | BPF_X: /* A += X */
-               jit->seen |= SEEN_XREG;
-               /* ar %r5,%r12 */
-               EMIT2(0x1a5c);
-               break;
-       case BPF_ALU | BPF_ADD | BPF_K: /* A += K */
-               if (!K)
+       switch (insn->code) {
+       /*
+        * BPF_MOV
+        */
+       case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
+               /* llgfr %dst,%src */
+               EMIT4(0xb9160000, dst_reg, src_reg);
+               break;
+       case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
+               /* lgr %dst,%src */
+               EMIT4(0xb9040000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
+               /* llilf %dst,imm */
+               EMIT6_IMM(0xc00f0000, dst_reg, imm);
+               break;
+       case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
+               /* lgfi %dst,imm */
+               EMIT6_IMM(0xc0010000, dst_reg, imm);
+               break;
+       /*
+        * BPF_LD 64
+        */
+       case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
+       {
+               /* 16 byte instruction that uses two 'struct bpf_insn' */
+               u64 imm64;
+
+               imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
+               /* lg %dst,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
+                             EMIT_CONST_U64(imm64));
+               insn_count = 2;
+               break;
+       }
+       /*
+        * BPF_ADD
+        */
+       case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
+               /* ar %dst,%src */
+               EMIT2(0x1a00, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
+               /* agr %dst,%src */
+               EMIT4(0xb9080000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
+               if (!imm)
                        break;
-               if (K <= 16383)
-                       /* ahi %r5,<K> */
-                       EMIT4_IMM(0xa75a0000, K);
-               else if (test_facility(21))
-                       /* alfi %r5,<K> */
-                       EMIT6_IMM(0xc25b0000, K);
-               else
-                       /* a %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x5a50d000, EMIT_CONST(K));
+               /* alfi %dst,imm */
+               EMIT6_IMM(0xc20b0000, dst_reg, imm);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
+               if (!imm)
+                       break;
+               /* agfi %dst,imm */
+               EMIT6_IMM(0xc2080000, dst_reg, imm);
+               break;
+       /*
+        * BPF_SUB
+        */
+       case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
+               /* sr %dst,%src */
+               EMIT2(0x1b00, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ALU | BPF_SUB | BPF_X: /* A -= X */
-               jit->seen |= SEEN_XREG;
-               /* sr %r5,%r12 */
-               EMIT2(0x1b5c);
+       case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
+               /* sgr %dst,%src */
+               EMIT4(0xb9090000, dst_reg, src_reg);
                break;
-       case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */
-               if (!K)
+       case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
+               if (!imm)
                        break;
-               if (K <= 16384)
-                       /* ahi %r5,-K */
-                       EMIT4_IMM(0xa75a0000, -K);
-               else if (test_facility(21))
-                       /* alfi %r5,-K */
-                       EMIT6_IMM(0xc25b0000, -K);
-               else
-                       /* s %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x5b50d000, EMIT_CONST(K));
-               break;
-       case BPF_ALU | BPF_MUL | BPF_X: /* A *= X */
-               jit->seen |= SEEN_XREG;
-               /* msr %r5,%r12 */
-               EMIT4(0xb252005c);
-               break;
-       case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */
-               if (K <= 16383)
-                       /* mhi %r5,K */
-                       EMIT4_IMM(0xa75c0000, K);
-               else if (test_facility(34))
-                       /* msfi %r5,<K> */
-                       EMIT6_IMM(0xc2510000, K);
-               else
-                       /* ms %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x7150d000, EMIT_CONST(K));
+               /* alfi %dst,-imm */
+               EMIT6_IMM(0xc20b0000, dst_reg, -imm);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ALU | BPF_DIV | BPF_X: /* A /= X */
-               jit->seen |= SEEN_XREG | SEEN_RET0;
-               /* ltr %r12,%r12 */
-               EMIT2(0x12cc);
-               /* jz <ret0> */
-               EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
-               /* lhi %r4,0 */
-               EMIT4(0xa7480000);
-               /* dlr %r4,%r12 */
-               EMIT4(0xb997004c);
-               break;
-       case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */
-               if (K == 1)
+       case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
+               if (!imm)
+                       break;
+               /* agfi %dst,-imm */
+               EMIT6_IMM(0xc2080000, dst_reg, -imm);
+               break;
+       /*
+        * BPF_MUL
+        */
+       case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
+               /* msr %dst,%src */
+               EMIT4(0xb2520000, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
+               /* msgr %dst,%src */
+               EMIT4(0xb90c0000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
+               if (imm == 1)
+                       break;
+               /* msfi %r5,imm */
+               EMIT6_IMM(0xc2010000, dst_reg, imm);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
+               if (imm == 1)
                        break;
-               /* lhi %r4,0 */
-               EMIT4(0xa7480000);
-               /* dl %r4,<d(K)>(%r13) */
-               EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K));
-               break;
-       case BPF_ALU | BPF_MOD | BPF_X: /* A %= X */
-               jit->seen |= SEEN_XREG | SEEN_RET0;
-               /* ltr %r12,%r12 */
-               EMIT2(0x12cc);
+               /* msgfi %dst,imm */
+               EMIT6_IMM(0xc2000000, dst_reg, imm);
+               break;
+       /*
+        * BPF_DIV / BPF_MOD
+        */
+       case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
+       case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
+       {
+               int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
+
+               jit->seen |= SEEN_RET0;
+               /* ltr %src,%src (if src == 0 goto fail) */
+               EMIT2(0x1200, src_reg, src_reg);
                /* jz <ret0> */
-               EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
-               /* lhi %r4,0 */
-               EMIT4(0xa7480000);
-               /* dlr %r4,%r12 */
-               EMIT4(0xb997004c);
-               /* lr %r5,%r4 */
-               EMIT2(0x1854);
-               break;
-       case BPF_ALU | BPF_MOD | BPF_K: /* A %= K */
-               if (K == 1) {
-                       /* lhi %r5,0 */
-                       EMIT4(0xa7580000);
+               EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
+               /* lhi %w0,0 */
+               EMIT4_IMM(0xa7080000, REG_W0, 0);
+               /* lr %w1,%dst */
+               EMIT2(0x1800, REG_W1, dst_reg);
+               /* dlr %w0,%src */
+               EMIT4(0xb9970000, REG_W0, src_reg);
+               /* llgfr %dst,%rc */
+               EMIT4(0xb9160000, dst_reg, rc_reg);
+               break;
+       }
+       case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
+       case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
+       {
+               int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
+
+               jit->seen |= SEEN_RET0;
+               /* ltgr %src,%src (if src == 0 goto fail) */
+               EMIT4(0xb9020000, src_reg, src_reg);
+               /* jz <ret0> */
+               EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
+               /* lghi %w0,0 */
+               EMIT4_IMM(0xa7090000, REG_W0, 0);
+               /* lgr %w1,%dst */
+               EMIT4(0xb9040000, REG_W1, dst_reg);
+               /* dlgr %w0,%dst */
+               EMIT4(0xb9870000, REG_W0, src_reg);
+               /* lgr %dst,%rc */
+               EMIT4(0xb9040000, dst_reg, rc_reg);
+               break;
+       }
+       case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
+       case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
+       {
+               int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
+
+               if (imm == 1) {
+                       if (BPF_OP(insn->code) == BPF_MOD)
+                               /* lhgi %dst,0 */
+                               EMIT4_IMM(0xa7090000, dst_reg, 0);
                        break;
                }
-               /* lhi %r4,0 */
-               EMIT4(0xa7480000);
-               /* dl %r4,<d(K)>(%r13) */
-               EMIT6_DISP(0xe340d000, 0x0097, EMIT_CONST(K));
-               /* lr %r5,%r4 */
-               EMIT2(0x1854);
-               break;
-       case BPF_ALU | BPF_AND | BPF_X: /* A &= X */
-               jit->seen |= SEEN_XREG;
-               /* nr %r5,%r12 */
-               EMIT2(0x145c);
-               break;
-       case BPF_ALU | BPF_AND | BPF_K: /* A &= K */
-               if (test_facility(21))
-                       /* nilf %r5,<K> */
-                       EMIT6_IMM(0xc05b0000, K);
-               else
-                       /* n %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x5450d000, EMIT_CONST(K));
-               break;
-       case BPF_ALU | BPF_OR | BPF_X: /* A |= X */
-               jit->seen |= SEEN_XREG;
-               /* or %r5,%r12 */
-               EMIT2(0x165c);
-               break;
-       case BPF_ALU | BPF_OR | BPF_K: /* A |= K */
-               if (test_facility(21))
-                       /* oilf %r5,<K> */
-                       EMIT6_IMM(0xc05d0000, K);
-               else
-                       /* o %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x5650d000, EMIT_CONST(K));
+               /* lhi %w0,0 */
+               EMIT4_IMM(0xa7080000, REG_W0, 0);
+               /* lr %w1,%dst */
+               EMIT2(0x1800, REG_W1, dst_reg);
+               /* dl %w0,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
+                             EMIT_CONST_U32(imm));
+               /* llgfr %dst,%rc */
+               EMIT4(0xb9160000, dst_reg, rc_reg);
+               break;
+       }
+       case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
+       case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
+       {
+               int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
+
+               if (imm == 1) {
+                       if (BPF_OP(insn->code) == BPF_MOD)
+                               /* lhgi %dst,0 */
+                               EMIT4_IMM(0xa7090000, dst_reg, 0);
+                       break;
+               }
+               /* lghi %w0,0 */
+               EMIT4_IMM(0xa7090000, REG_W0, 0);
+               /* lgr %w1,%dst */
+               EMIT4(0xb9040000, REG_W1, dst_reg);
+               /* dlg %w0,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
+                             EMIT_CONST_U64(imm));
+               /* lgr %dst,%rc */
+               EMIT4(0xb9040000, dst_reg, rc_reg);
+               break;
+       }
+       /*
+        * BPF_AND
+        */
+       case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
+               /* nr %dst,%src */
+               EMIT2(0x1400, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
+               /* ngr %dst,%src */
+               EMIT4(0xb9800000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
+               /* nilf %dst,imm */
+               EMIT6_IMM(0xc00b0000, dst_reg, imm);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ANC | SKF_AD_ALU_XOR_X: /* A ^= X; */
-       case BPF_ALU | BPF_XOR | BPF_X:
-               jit->seen |= SEEN_XREG;
-               /* xr %r5,%r12 */
-               EMIT2(0x175c);
+       case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
+               /* ng %dst,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
+                             EMIT_CONST_U64(imm));
                break;
-       case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */
-               if (!K)
+       /*
+        * BPF_OR
+        */
+       case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
+               /* or %dst,%src */
+               EMIT2(0x1600, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
+               /* ogr %dst,%src */
+               EMIT4(0xb9810000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
+               /* oilf %dst,imm */
+               EMIT6_IMM(0xc00d0000, dst_reg, imm);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
+               /* og %dst,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
+                             EMIT_CONST_U64(imm));
+               break;
+       /*
+        * BPF_XOR
+        */
+       case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
+               /* xr %dst,%src */
+               EMIT2(0x1700, dst_reg, src_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
+               /* xgr %dst,%src */
+               EMIT4(0xb9820000, dst_reg, src_reg);
+               break;
+       case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
+               if (!imm)
                        break;
-               /* x %r5,<d(K)>(%r13) */
-               EMIT4_DISP(0x5750d000, EMIT_CONST(K));
+               /* xilf %dst,imm */
+               EMIT6_IMM(0xc0070000, dst_reg, imm);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
+               /* xg %dst,<d(imm)>(%l) */
+               EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
+                             EMIT_CONST_U64(imm));
+               break;
+       /*
+        * BPF_LSH
+        */
+       case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
+               /* sll %dst,0(%src) */
+               EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */
-               jit->seen |= SEEN_XREG;
-               /* sll %r5,0(%r12) */
-               EMIT4(0x8950c000);
+       case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
+               /* sllg %dst,%dst,0(%src) */
+               EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
                break;
-       case BPF_ALU | BPF_LSH | BPF_K: /* A <<= K */
-               if (K == 0)
+       case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
+               if (imm == 0)
                        break;
-               /* sll %r5,K */
-               EMIT4_DISP(0x89500000, K);
+               /* sll %dst,imm(%r0) */
+               EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */
-               jit->seen |= SEEN_XREG;
-               /* srl %r5,0(%r12) */
-               EMIT4(0x8850c000);
+       case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
+               if (imm == 0)
+                       break;
+               /* sllg %dst,%dst,imm(%r0) */
+               EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
+               break;
+       /*
+        * BPF_RSH
+        */
+       case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
+               /* srl %dst,0(%src) */
+               EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
+               EMIT_ZERO(dst_reg);
                break;
-       case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */
-               if (K == 0)
+       case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
+               /* srlg %dst,%dst,0(%src) */
+               EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
+               break;
+       case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
+               if (imm == 0)
                        break;
-               /* srl %r5,K */
-               EMIT4_DISP(0x88500000, K);
-               break;
-       case BPF_ALU | BPF_NEG: /* A = -A */
-               /* lcr %r5,%r5 */
-               EMIT2(0x1355);
-               break;
-       case BPF_JMP | BPF_JA: /* ip += K */
-               offset = addrs[i + K] + jit->start - jit->prg;
-               EMIT4_PCREL(0xa7f40000, offset);
-               break;
-       case BPF_JMP | BPF_JGT | BPF_K: /* ip += (A > K) ? jt : jf */
-               mask = 0x200000; /* jh */
-               goto kbranch;
-       case BPF_JMP | BPF_JGE | BPF_K: /* ip += (A >= K) ? jt : jf */
-               mask = 0xa00000; /* jhe */
-               goto kbranch;
-       case BPF_JMP | BPF_JEQ | BPF_K: /* ip += (A == K) ? jt : jf */
-               mask = 0x800000; /* je */
-kbranch:       /* Emit compare if the branch targets are different */
-               if (filter->jt != filter->jf) {
-                       if (test_facility(21))
-                               /* clfi %r5,<K> */
-                               EMIT6_IMM(0xc25f0000, K);
-                       else
-                               /* cl %r5,<d(K)>(%r13) */
-                               EMIT4_DISP(0x5550d000, EMIT_CONST(K));
-               }
-branch:                if (filter->jt == filter->jf) {
-                       if (filter->jt == 0)
-                               break;
-                       /* j <jt> */
-                       offset = addrs[i + filter->jt] + jit->start - jit->prg;
-                       EMIT4_PCREL(0xa7f40000, offset);
+               /* srl %dst,imm(%r0) */
+               EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
+               if (imm == 0)
                        break;
-               }
-               if (filter->jt != 0) {
-                       /* brc  <mask>,<jt> */
-                       offset = addrs[i + filter->jt] + jit->start - jit->prg;
-                       EMIT4_PCREL(0xa7040000 | mask, offset);
-               }
-               if (filter->jf != 0) {
-                       /* brc  <mask^15>,<jf> */
-                       offset = addrs[i + filter->jf] + jit->start - jit->prg;
-                       EMIT4_PCREL(0xa7040000 | (mask ^ 0xf00000), offset);
-               }
+               /* srlg %dst,%dst,imm(%r0) */
+               EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
                break;
-       case BPF_JMP | BPF_JSET | BPF_K: /* ip += (A & K) ? jt : jf */
-               mask = 0x700000; /* jnz */
-               /* Emit test if the branch targets are different */
-               if (filter->jt != filter->jf) {
-                       if (K > 65535) {
-                               /* lr %r4,%r5 */
-                               EMIT2(0x1845);
-                               /* n %r4,<d(K)>(%r13) */
-                               EMIT4_DISP(0x5440d000, EMIT_CONST(K));
-                       } else
-                               /* tmll %r5,K */
-                               EMIT4_IMM(0xa7510000, K);
-               }
-               goto branch;
-       case BPF_JMP | BPF_JGT | BPF_X: /* ip += (A > X) ? jt : jf */
-               mask = 0x200000; /* jh */
-               goto xbranch;
-       case BPF_JMP | BPF_JGE | BPF_X: /* ip += (A >= X) ? jt : jf */
-               mask = 0xa00000; /* jhe */
-               goto xbranch;
-       case BPF_JMP | BPF_JEQ | BPF_X: /* ip += (A == X) ? jt : jf */
-               mask = 0x800000; /* je */
-xbranch:       /* Emit compare if the branch targets are different */
-               if (filter->jt != filter->jf) {
-                       jit->seen |= SEEN_XREG;
-                       /* clr %r5,%r12 */
-                       EMIT2(0x155c);
-               }
-               goto branch;
-       case BPF_JMP | BPF_JSET | BPF_X: /* ip += (A & X) ? jt : jf */
-               mask = 0x700000; /* jnz */
-               /* Emit test if the branch targets are different */
-               if (filter->jt != filter->jf) {
-                       jit->seen |= SEEN_XREG;
-                       /* lr %r4,%r5 */
-                       EMIT2(0x1845);
-                       /* nr %r4,%r12 */
-                       EMIT2(0x144c);
+       /*
+        * BPF_ARSH
+        */
+       case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
+               /* srag %dst,%dst,0(%src) */
+               EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
+               break;
+       case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
+               if (imm == 0)
+                       break;
+               /* srag %dst,%dst,imm(%r0) */
+               EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
+               break;
+       /*
+        * BPF_NEG
+        */
+       case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
+               /* lcr %dst,%dst */
+               EMIT2(0x1300, dst_reg, dst_reg);
+               EMIT_ZERO(dst_reg);
+               break;
+       case BPF_ALU64 | BPF_NEG: /* dst = -dst */
+               /* lcgr %dst,%dst */
+               EMIT4(0xb9130000, dst_reg, dst_reg);
+               break;
+       /*
+        * BPF_FROM_BE/LE
+        */
+       case BPF_ALU | BPF_END | BPF_FROM_BE:
+               /* s390 is big endian, therefore only clear high order bytes */
+               switch (imm) {
+               case 16: /* dst = (u16) cpu_to_be16(dst) */
+                       /* llghr %dst,%dst */
+                       EMIT4(0xb9850000, dst_reg, dst_reg);
+                       break;
+               case 32: /* dst = (u32) cpu_to_be32(dst) */
+                       /* llgfr %dst,%dst */
+                       EMIT4(0xb9160000, dst_reg, dst_reg);
+                       break;
+               case 64: /* dst = (u64) cpu_to_be64(dst) */
+                       break;
                }
-               goto branch;
-       case BPF_LD | BPF_W | BPF_ABS: /* A = *(u32 *) (skb->data+K) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_WORD;
-               offset = jit->off_load_word;
-               goto load_abs;
-       case BPF_LD | BPF_H | BPF_ABS: /* A = *(u16 *) (skb->data+K) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_HALF;
-               offset = jit->off_load_half;
-               goto load_abs;
-       case BPF_LD | BPF_B | BPF_ABS: /* A = *(u8 *) (skb->data+K) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_BYTE;
-               offset = jit->off_load_byte;
-load_abs:      if ((int) K < 0)
-                       goto out;
-call_fn:       /* lg %r1,<d(function)>(%r13) */
-               EMIT6_DISP(0xe310d000, 0x0004, offset);
-               /* l %r3,<d(K)>(%r13) */
-               EMIT4_DISP(0x5830d000, EMIT_CONST(K));
-               /* basr %r8,%r1 */
-               EMIT2(0x0d81);
-               /* jnz <ret0> */
-               EMIT4_PCREL(0xa7740000, (jit->ret0_ip - jit->prg));
                break;
-       case BPF_LD | BPF_W | BPF_IND: /* A = *(u32 *) (skb->data+K+X) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IWORD;
-               offset = jit->off_load_iword;
-               goto call_fn;
-       case BPF_LD | BPF_H | BPF_IND: /* A = *(u16 *) (skb->data+K+X) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IHALF;
-               offset = jit->off_load_ihalf;
-               goto call_fn;
-       case BPF_LD | BPF_B | BPF_IND: /* A = *(u8 *) (skb->data+K+X) */
-               jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IBYTE;
-               offset = jit->off_load_ibyte;
-               goto call_fn;
-       case BPF_LDX | BPF_B | BPF_MSH:
-               /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */
-               jit->seen |= SEEN_RET0;
-               if ((int) K < 0) {
-                       /* j <ret0> */
-                       EMIT4_PCREL(0xa7f40000, (jit->ret0_ip - jit->prg));
+       case BPF_ALU | BPF_END | BPF_FROM_LE:
+               switch (imm) {
+               case 16: /* dst = (u16) cpu_to_le16(dst) */
+                       /* lrvr %dst,%dst */
+                       EMIT4(0xb91f0000, dst_reg, dst_reg);
+                       /* srl %dst,16(%r0) */
+                       EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
+                       /* llghr %dst,%dst */
+                       EMIT4(0xb9850000, dst_reg, dst_reg);
+                       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);
+                       break;
+               case 64: /* dst = (u64) cpu_to_le64(dst) */
+                       /* lrvgr %dst,%dst */
+                       EMIT4(0xb90f0000, dst_reg, dst_reg);
                        break;
                }
-               jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH;
-               offset = jit->off_load_bmsh;
-               goto call_fn;
-       case BPF_LD | BPF_W | BPF_LEN: /*       A = skb->len; */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
-               /* l %r5,<d(len)>(%r2) */
-               EMIT4_DISP(0x58502000, offsetof(struct sk_buff, len));
-               break;
-       case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */
-               jit->seen |= SEEN_XREG;
-               /* l %r12,<d(len)>(%r2) */
-               EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len));
-               break;
-       case BPF_LD | BPF_IMM: /* A = K */
-               if (K <= 16383)
-                       /* lhi %r5,K */
-                       EMIT4_IMM(0xa7580000, K);
-               else if (test_facility(21))
-                       /* llilf %r5,<K> */
-                       EMIT6_IMM(0xc05f0000, K);
-               else
-                       /* l %r5,<d(K)>(%r13) */
-                       EMIT4_DISP(0x5850d000, EMIT_CONST(K));
-               break;
-       case BPF_LDX | BPF_IMM: /* X = K */
-               jit->seen |= SEEN_XREG;
-               if (K <= 16383)
-                       /* lhi %r12,<K> */
-                       EMIT4_IMM(0xa7c80000, K);
-               else if (test_facility(21))
-                       /* llilf %r12,<K> */
-                       EMIT6_IMM(0xc0cf0000, K);
-               else
-                       /* l %r12,<d(K)>(%r13) */
-                       EMIT4_DISP(0x58c0d000, EMIT_CONST(K));
                break;
-       case BPF_LD | BPF_MEM: /* A = mem[K] */
+       /*
+        * BPF_ST(X)
+        */
+       case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
+               /* stcy %src,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
+               /* sthy %src,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
+               /* sty %src,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
+               /* stg %src,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
+               /* lhi %w0,imm */
+               EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
+               /* stcy %w0,off(dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
+               /* lhi %w0,imm */
+               EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
+               /* sthy %w0,off(dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
                jit->seen |= SEEN_MEM;
-               /* l %r5,<K>(%r15) */
-               EMIT4_DISP(0x5850f000,
-                          (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
-               break;
-       case BPF_LDX | BPF_MEM: /* X = mem[K] */
-               jit->seen |= SEEN_XREG | SEEN_MEM;
-               /* l %r12,<K>(%r15) */
-               EMIT4_DISP(0x58c0f000,
-                          (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
-               break;
-       case BPF_MISC | BPF_TAX: /* X = A */
-               jit->seen |= SEEN_XREG;
-               /* lr %r12,%r5 */
-               EMIT2(0x18c5);
-               break;
-       case BPF_MISC | BPF_TXA: /* A = X */
-               jit->seen |= SEEN_XREG;
-               /* lr %r5,%r12 */
-               EMIT2(0x185c);
-               break;
-       case BPF_RET | BPF_K:
-               if (K == 0) {
-                       jit->seen |= SEEN_RET0;
-                       if (last)
-                               break;
-                       /* j <ret0> */
-                       EMIT4_PCREL(0xa7f40000, jit->ret0_ip - jit->prg);
-               } else {
-                       if (K <= 16383)
-                               /* lghi %r2,K */
-                               EMIT4_IMM(0xa7290000, K);
-                       else
-                               /* llgf %r2,<K>(%r13) */
-                               EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K));
-                       /* j <exit> */
-                       if (last && !(jit->seen & SEEN_RET0))
-                               break;
-                       EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
-               }
                break;
-       case BPF_RET | BPF_A:
-               /* llgfr %r2,%r5 */
-               EMIT4(0xb9160025);
+       case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
+               /* llilf %w0,imm  */
+               EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
+               /* sty %w0,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
+               /* lgfi %w0,imm */
+               EMIT6_IMM(0xc0010000, REG_W0, imm);
+               /* stg %w0,off(%dst) */
+               EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       /*
+        * BPF_STX XADD (atomic_add)
+        */
+       case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
+               /* laal %w0,%src,off(%dst) */
+               EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
+                             dst_reg, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
+               /* laalg %w0,%src,off(%dst) */
+               EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
+                             dst_reg, off);
+               jit->seen |= SEEN_MEM;
+               break;
+       /*
+        * BPF_LDX
+        */
+       case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
+               /* llgc %dst,0(off,%src) */
+               EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
+               jit->seen |= SEEN_MEM;
+               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;
+               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);
+               break;
+       case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
+               /* lg %dst,0(off,%src) */
+               jit->seen |= SEEN_MEM;
+               EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
+               break;
+       /*
+        * BPF_JMP / CALL
+        */
+       case BPF_JMP | BPF_CALL:
+       {
+               /*
+                * b0 = (__bpf_call_base + imm)(b1, b2, b3, b4, b5)
+                */
+               const u64 func = (u64)__bpf_call_base + imm;
+
+               REG_SET_SEEN(BPF_REG_5);
+               jit->seen |= SEEN_FUNC;
+               /* lg %w1,<d(imm)>(%l) */
+               EMIT6_DISP(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
+                          EMIT_CONST_U64(func));
+               /* basr %r14,%w1 */
+               EMIT2(0x0d00, REG_14, REG_W1);
+               /* lgr %b0,%r2: load return value into %b0 */
+               EMIT4(0xb9040000, BPF_REG_0, REG_2);
+               break;
+       }
+       case BPF_JMP | BPF_EXIT: /* return b0 */
+               last = (i == fp->len - 1) ? 1 : 0;
+               if (last && !(jit->seen & SEEN_RET0))
+                       break;
                /* j <exit> */
                EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
                break;
-       case BPF_ST: /* mem[K] = A */
-               jit->seen |= SEEN_MEM;
-               /* st %r5,<K>(%r15) */
-               EMIT4_DISP(0x5050f000,
-                          (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
-               break;
-       case BPF_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */
-               jit->seen |= SEEN_XREG | SEEN_MEM;
-               /* st %r12,<K>(%r15) */
-               EMIT4_DISP(0x50c0f000,
-                          (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
-               break;
-       case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-               /* icm  %r5,3,<d(protocol)>(%r2) */
-               EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, protocol));
-               break;
-       case BPF_ANC | SKF_AD_IFINDEX:  /* if (!skb->dev) return 0;
-                                        * A = skb->dev->ifindex */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
-               jit->seen |= SEEN_RET0;
-               /* lg %r1,<d(dev)>(%r2) */
-               EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
-               /* ltgr %r1,%r1 */
-               EMIT4(0xb9020011);
-               /* jz <ret0> */
-               EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
-               /* l %r5,<d(ifindex)>(%r1) */
-               EMIT4_DISP(0x58501000, offsetof(struct net_device, ifindex));
-               break;
-       case BPF_ANC | SKF_AD_MARK: /* A = skb->mark */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
-               /* l %r5,<d(mark)>(%r2) */
-               EMIT4_DISP(0x58502000, offsetof(struct sk_buff, mark));
-               break;
-       case BPF_ANC | SKF_AD_QUEUE: /* A = skb->queue_mapping */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-               /* icm  %r5,3,<d(queue_mapping)>(%r2) */
-               EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, queue_mapping));
-               break;
-       case BPF_ANC | SKF_AD_HATYPE:   /* if (!skb->dev) return 0;
-                                        * A = skb->dev->type */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
-               jit->seen |= SEEN_RET0;
-               /* lg %r1,<d(dev)>(%r2) */
-               EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
-               /* ltgr %r1,%r1 */
-               EMIT4(0xb9020011);
-               /* jz <ret0> */
-               EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-               /* icm  %r5,3,<d(type)>(%r1) */
-               EMIT4_DISP(0xbf531000, offsetof(struct net_device, type));
-               break;
-       case BPF_ANC | SKF_AD_RXHASH: /* A = skb->hash */
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
-               /* l %r5,<d(hash)>(%r2) */
-               EMIT4_DISP(0x58502000, offsetof(struct sk_buff, hash));
-               break;
-       case BPF_ANC | SKF_AD_VLAN_TAG:
-       case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
-               BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
-               BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-               /* icm  %r5,3,<d(vlan_tci)>(%r2) */
-               EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, vlan_tci));
-               if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
-                       /* nill %r5,0xefff */
-                       EMIT4_IMM(0xa5570000, ~VLAN_TAG_PRESENT);
-               } else {
-                       /* nill %r5,0x1000 */
-                       EMIT4_IMM(0xa5570000, VLAN_TAG_PRESENT);
-                       /* srl %r5,12 */
-                       EMIT4_DISP(0x88500000, 12);
-               }
+       /*
+        * Branch relative (number of skipped instructions) to offset on
+        * condition.
+        *
+        * Condition code to mask mapping:
+        *
+        * CC | Description        | Mask
+        * ------------------------------
+        * 0  | Operands equal     |    8
+        * 1  | First operand low  |    4
+        * 2  | First operand high |    2
+        * 3  | Unused             |    1
+        *
+        * For s390x relative branches: ip = ip + off_bytes
+        * For BPF relative branches:   insn = insn + off_insns + 1
+        *
+        * For example for s390x with offset 0 we jump to the branch
+        * instruction itself (loop) and for BPF with offset 0 we
+        * branch to the instruction behind the branch.
+        */
+       case BPF_JMP | BPF_JA: /* if (true) */
+               mask = 0xf000; /* j */
+               goto branch_oc;
+       case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
+               mask = 0x2000; /* jh */
+               goto branch_ks;
+       case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
+               mask = 0xa000; /* jhe */
+               goto branch_ks;
+       case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
+               mask = 0x2000; /* jh */
+               goto branch_ku;
+       case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
+               mask = 0xa000; /* jhe */
+               goto branch_ku;
+       case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
+               mask = 0x7000; /* jne */
+               goto branch_ku;
+       case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
+               mask = 0x8000; /* je */
+               goto branch_ku;
+       case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
+               mask = 0x7000; /* jnz */
+               /* lgfi %w1,imm (load sign extend imm) */
+               EMIT6_IMM(0xc0010000, REG_W1, imm);
+               /* ngr %w1,%dst */
+               EMIT4(0xb9800000, REG_W1, dst_reg);
+               goto branch_oc;
+
+       case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
+               mask = 0x2000; /* jh */
+               goto branch_xs;
+       case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
+               mask = 0xa000; /* jhe */
+               goto branch_xs;
+       case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
+               mask = 0x2000; /* jh */
+               goto branch_xu;
+       case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
+               mask = 0xa000; /* jhe */
+               goto branch_xu;
+       case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
+               mask = 0x7000; /* jne */
+               goto branch_xu;
+       case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
+               mask = 0x8000; /* je */
+               goto branch_xu;
+       case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
+               mask = 0x7000; /* jnz */
+               /* ngrk %w1,%dst,%src */
+               EMIT4_RRF(0xb9e40000, REG_W1, dst_reg, src_reg);
+               goto branch_oc;
+branch_ks:
+               /* lgfi %w1,imm (load sign extend imm) */
+               EMIT6_IMM(0xc0010000, REG_W1, imm);
+               /* cgrj %dst,%w1,mask,off */
+               EMIT6_PCREL(0xec000000, 0x0064, dst_reg, REG_W1, i, off, mask);
+               break;
+branch_ku:
+               /* lgfi %w1,imm (load sign extend imm) */
+               EMIT6_IMM(0xc0010000, REG_W1, imm);
+               /* clgrj %dst,%w1,mask,off */
+               EMIT6_PCREL(0xec000000, 0x0065, dst_reg, REG_W1, i, off, mask);
+               break;
+branch_xs:
+               /* cgrj %dst,%src,mask,off */
+               EMIT6_PCREL(0xec000000, 0x0064, dst_reg, src_reg, i, off, mask);
+               break;
+branch_xu:
+               /* clgrj %dst,%src,mask,off */
+               EMIT6_PCREL(0xec000000, 0x0065, dst_reg, src_reg, i, off, mask);
+               break;
+branch_oc:
+               /* brc mask,jmp_off (branch instruction needs 4 bytes) */
+               jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
+               EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
                break;
-       case BPF_ANC | SKF_AD_PKTTYPE:
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-               /* ic %r5,<d(pkt_type_offset)>(%r2) */
-               EMIT4_DISP(0x43502000, PKT_TYPE_OFFSET());
-               /* srl %r5,5 */
-               EMIT4_DISP(0x88500000, 5);
-               break;
-       case BPF_ANC | SKF_AD_CPU: /* A = smp_processor_id() */
-#ifdef CONFIG_SMP
-               /* l %r5,<d(cpu_nr)> */
-               EMIT4_DISP(0x58500000, offsetof(struct _lowcore, cpu_nr));
-#else
-               /* lhi %r5,0 */
-               EMIT4(0xa7580000);
-#endif
+       /*
+        * BPF_LD
+        */
+       case BPF_LD | BPF_ABS | BPF_B: /* b0 = *(u8 *) (skb->data+imm) */
+       case BPF_LD | BPF_IND | BPF_B: /* b0 = *(u8 *) (skb->data+imm+src) */
+               if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
+                       func_addr = __pa(sk_load_byte_pos);
+               else
+                       func_addr = __pa(sk_load_byte);
+               goto call_fn;
+       case BPF_LD | BPF_ABS | BPF_H: /* b0 = *(u16 *) (skb->data+imm) */
+       case BPF_LD | BPF_IND | BPF_H: /* b0 = *(u16 *) (skb->data+imm+src) */
+               if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
+                       func_addr = __pa(sk_load_half_pos);
+               else
+                       func_addr = __pa(sk_load_half);
+               goto call_fn;
+       case BPF_LD | BPF_ABS | BPF_W: /* b0 = *(u32 *) (skb->data+imm) */
+       case BPF_LD | BPF_IND | BPF_W: /* b0 = *(u32 *) (skb->data+imm+src) */
+               if ((BPF_MODE(insn->code) == BPF_ABS) && (imm >= 0))
+                       func_addr = __pa(sk_load_word_pos);
+               else
+                       func_addr = __pa(sk_load_word);
+               goto call_fn;
+call_fn:
+               jit->seen |= SEEN_SKB | SEEN_RET0 | SEEN_FUNC;
+               REG_SET_SEEN(REG_14); /* Return address of possible func call */
+
+               /*
+                * Implicit input:
+                *  BPF_REG_6    (R7) : skb pointer
+                *  REG_SKB_DATA (R12): skb data pointer
+                *
+                * Calculated input:
+                *  BPF_REG_2    (R3) : offset of byte(s) to fetch in skb
+                *  BPF_REG_5    (R6) : return address
+                *
+                * Output:
+                *  BPF_REG_0    (R14): data read from skb
+                *
+                * Scratch registers (BPF_REG_1-5)
+                */
+
+               /* Call function: llilf %w1,func_addr  */
+               EMIT6_IMM(0xc00f0000, REG_W1, func_addr);
+
+               /* Offset: lgfi %b2,imm */
+               EMIT6_IMM(0xc0010000, BPF_REG_2, imm);
+               if (BPF_MODE(insn->code) == BPF_IND)
+                       /* agfr %b2,%src (%src is s32 here) */
+                       EMIT4(0xb9180000, BPF_REG_2, src_reg);
+
+               /* basr %b5,%w1 (%b5 is call saved) */
+               EMIT2(0x0d00, BPF_REG_5, REG_W1);
+
+               /*
+                * Note: For fast access we jump directly after the
+                * jnz instruction from bpf_jit.S
+                */
+               /* jnz <ret0> */
+               EMIT4_PCREL(0xa7740000, jit->ret0_ip - jit->prg);
                break;
        default: /* too complex, give up */
-               goto out;
+               pr_err("Unknown opcode %02x\n", insn->code);
+               return -1;
+       }
+       return insn_count;
+}
+
+/*
+ * Compile eBPF program into s390x code
+ */
+static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
+{
+       int i, insn_count;
+
+       jit->lit = jit->lit_start;
+       jit->prg = 0;
+
+       bpf_jit_prologue(jit);
+       for (i = 0; i < fp->len; i += insn_count) {
+               insn_count = bpf_jit_insn(jit, fp, i);
+               if (insn_count < 0)
+                       return -1;
+               jit->addrs[i + 1] = jit->prg; /* Next instruction address */
        }
-       addrs[i] = jit->prg - jit->start;
+       bpf_jit_epilogue(jit);
+
+       jit->lit_start = jit->prg;
+       jit->size = jit->lit;
+       jit->size_prg = jit->prg;
        return 0;
-out:
-       return -1;
 }
 
+/*
+ * Classic BPF function stub. BPF programs will be converted into
+ * eBPF and then bpf_int_jit_compile() will be called.
+ */
 void bpf_jit_compile(struct bpf_prog *fp)
 {
-       struct bpf_binary_header *header = NULL;
-       unsigned long size, prg_len, lit_len;
-       struct bpf_jit jit, cjit;
-       unsigned int *addrs;
-       int pass, i;
+}
+
+/*
+ * Compile eBPF program "fp"
+ */
+void bpf_int_jit_compile(struct bpf_prog *fp)
+{
+       struct bpf_binary_header *header;
+       struct bpf_jit jit;
+       int pass;
 
        if (!bpf_jit_enable)
                return;
-       addrs = kcalloc(fp->len, sizeof(*addrs), GFP_KERNEL);
-       if (addrs == NULL)
+       memset(&jit, 0, sizeof(jit));
+       jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
+       if (jit.addrs == NULL)
                return;
-       memset(&jit, 0, sizeof(cjit));
-       memset(&cjit, 0, sizeof(cjit));
-
-       for (pass = 0; pass < 10; pass++) {
-               jit.prg = jit.start;
-               jit.lit = jit.mid;
-
-               bpf_jit_prologue(&jit);
-               bpf_jit_noleaks(&jit, fp->insns);
-               for (i = 0; i < fp->len; i++) {
-                       if (bpf_jit_insn(&jit, fp->insns + i, addrs, i,
-                                        i == fp->len - 1))
-                               goto out;
-               }
-               bpf_jit_epilogue(&jit);
-               if (jit.start) {
-                       WARN_ON(jit.prg > cjit.prg || jit.lit > cjit.lit);
-                       if (memcmp(&jit, &cjit, sizeof(jit)) == 0)
-                               break;
-               } else if (jit.prg == cjit.prg && jit.lit == cjit.lit) {
-                       prg_len = jit.prg - jit.start;
-                       lit_len = jit.lit - jit.mid;
-                       size = prg_len + lit_len;
-                       if (size >= BPF_SIZE_MAX)
-                               goto out;
-                       header = bpf_jit_binary_alloc(size, &jit.start,
-                                                     2, bpf_jit_fill_hole);
-                       if (!header)
-                               goto out;
-                       jit.prg = jit.mid = jit.start + prg_len;
-                       jit.lit = jit.end = jit.start + prg_len + lit_len;
-                       jit.base_ip += (unsigned long) jit.start;
-                       jit.exit_ip += (unsigned long) jit.start;
-                       jit.ret0_ip += (unsigned long) jit.start;
-               }
-               cjit = jit;
+       /*
+        * Three initial passes:
+        *   - 1/2: Determine clobbered registers
+        *   - 3:   Calculate program size and addrs arrray
+        */
+       for (pass = 1; pass <= 3; pass++) {
+               if (bpf_jit_prog(&jit, fp))
+                       goto free_addrs;
        }
+       /*
+        * Final pass: Allocate and generate program
+        */
+       if (jit.size >= BPF_SIZE_MAX)
+               goto free_addrs;
+       header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
+       if (!header)
+               goto free_addrs;
+       if (bpf_jit_prog(&jit, fp))
+               goto free_addrs;
        if (bpf_jit_enable > 1) {
-               bpf_jit_dump(fp->len, jit.end - jit.start, pass, jit.start);
-               if (jit.start)
-                       print_fn_code(jit.start, jit.mid - jit.start);
+               bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
+               if (jit.prg_buf)
+                       print_fn_code(jit.prg_buf, jit.size_prg);
        }
-       if (jit.start) {
+       if (jit.prg_buf) {
                set_memory_ro((unsigned long)header, header->pages);
-               fp->bpf_func = (void *) jit.start;
+               fp->bpf_func = (void *) jit.prg_buf;
                fp->jited = true;
        }
-out:
-       kfree(addrs);
+free_addrs:
+       kfree(jit.addrs);
 }
 
+/*
+ * Free eBPF program
+ */
 void bpf_jit_free(struct bpf_prog *fp)
 {
        unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;