--- /dev/null
+/*
+ * BPF Jit compiler for s390.
+ *
+ * Copyright IBM Corp. 2012
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <linux/moduleloader.h>
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <asm/cacheflush.h>
+#include <asm/processor.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;
+
+/*
+ * assembly code in arch/x86/net/bpf_jit.S
+ */
+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[];
+
+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;
+};
+
+#define BPF_SIZE_MAX 4096 /* Max size for program */
+
+#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 EMIT4(op) \
+({ \
+ if (jit->prg + 4 <= jit->mid) \
+ *(u32 *) jit->prg = op; \
+ jit->prg += 4; \
+})
+
+#define EMIT4_DISP(op, disp) \
+({ \
+ unsigned int __disp = (disp) & 0xfff; \
+ EMIT4(op | __disp); \
+})
+
+#define EMIT4_IMM(op, imm) \
+({ \
+ unsigned int __imm = (imm) & 0xffff; \
+ EMIT4(op | __imm); \
+})
+
+#define EMIT4_PCREL(op, pcrel) \
+({ \
+ long __pcrel = ((pcrel) >> 1) & 0xffff; \
+ EMIT4(op | __pcrel); \
+})
+
+#define EMIT6(op1, op2) \
+({ \
+ if (jit->prg + 6 <= jit->mid) { \
+ *(u32 *) jit->prg = op1; \
+ *(u16 *) (jit->prg + 4) = op2; \
+ } \
+ jit->prg += 6; \
+})
+
+#define EMIT6_DISP(op1, op2, disp) \
+({ \
+ unsigned int __disp = (disp) & 0xfff; \
+ EMIT6(op1 | __disp, op2); \
+})
+
+#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 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; \
+})
+
+static void bpf_jit_prologue(struct bpf_jit *jit)
+{
+ /* 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);
+ /* ahi %r15,<offset> */
+ EMIT4_IMM(0xa7fa0000, (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);
+
+ /* Setup literal pool */
+ if (jit->seen & SEEN_LITERAL) {
+ /* basr %r13,0 */
+ EMIT2(0x0dd0);
+ 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));
+ }
+}
+
+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);
+ }
+ jit->exit_ip = jit->prg;
+ /* 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);
+ /* br %r14 */
+ EMIT2(0x07fe);
+}
+
+/*
+ * make sure we dont leak kernel information to user
+ */
+static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
+{
+ /* 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_S_LD_W_ABS:
+ case BPF_S_LD_H_ABS:
+ case BPF_S_LD_B_ABS:
+ case BPF_S_LD_W_LEN:
+ case BPF_S_LD_W_IND:
+ case BPF_S_LD_H_IND:
+ case BPF_S_LD_B_IND:
+ case BPF_S_LDX_B_MSH:
+ case BPF_S_LD_IMM:
+ case BPF_S_LD_MEM:
+ case BPF_S_MISC_TXA:
+ case BPF_S_ANC_PROTOCOL:
+ case BPF_S_ANC_PKTTYPE:
+ case BPF_S_ANC_IFINDEX:
+ case BPF_S_ANC_MARK:
+ case BPF_S_ANC_QUEUE:
+ case BPF_S_ANC_HATYPE:
+ case BPF_S_ANC_RXHASH:
+ case BPF_S_ANC_CPU:
+ case BPF_S_RET_K:
+ /* first instruction sets A register */
+ break;
+ default: /* A = 0 */
+ /* lhi %r5,0 */
+ EMIT4(0xa7580000);
+ }
+}
+
+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;
+
+ K = filter->k;
+ switch (filter->code) {
+ case BPF_S_ALU_ADD_X: /* A += X */
+ jit->seen |= SEEN_XREG;
+ /* ar %r5,%r12 */
+ EMIT2(0x1a5c);
+ break;
+ case BPF_S_ALU_ADD_K: /* A += K */
+ if (!K)
+ break;
+ if (K <= 16383)
+ /* ahi %r5,<K> */
+ EMIT4_IMM(0xa75a0000, K);
+ else
+ /* a %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5a50d000, EMIT_CONST(K));
+ break;
+ case BPF_S_ALU_SUB_X: /* A -= X */
+ jit->seen |= SEEN_XREG;
+ /* sr %r5,%r12 */
+ EMIT2(0x1b5c);
+ break;
+ case BPF_S_ALU_SUB_K: /* A -= K */
+ if (!K)
+ break;
+ if (K <= 16384)
+ /* ahi %r5,-K */
+ EMIT4_IMM(0xa75a0000, -K);
+ else
+ /* s %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5b50d000, EMIT_CONST(K));
+ break;
+ case BPF_S_ALU_MUL_X: /* A *= X */
+ jit->seen |= SEEN_XREG;
+ /* msr %r5,%r12 */
+ EMIT4(0xb252005c);
+ break;
+ case BPF_S_ALU_MUL_K: /* A *= K */
+ if (K <= 16383)
+ /* mhi %r5,K */
+ EMIT4_IMM(0xa75c0000, K);
+ else
+ /* ms %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x7150d000, EMIT_CONST(K));
+ break;
+ case BPF_S_ALU_DIV_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);
+ /* dr %r4,%r12 */
+ EMIT2(0x1d4c);
+ break;
+ case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K) */
+ /* m %r4,<d(K)>(%r13) */
+ EMIT4_DISP(0x5c40d000, EMIT_CONST(K));
+ /* lr %r5,%r4 */
+ EMIT2(0x1854);
+ break;
+ case BPF_S_ALU_AND_X: /* A &= X */
+ jit->seen |= SEEN_XREG;
+ /* nr %r5,%r12 */
+ EMIT2(0x145c);
+ break;
+ case BPF_S_ALU_AND_K: /* A &= K */
+ /* n %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5450d000, EMIT_CONST(K));
+ break;
+ case BPF_S_ALU_OR_X: /* A |= X */
+ jit->seen |= SEEN_XREG;
+ /* or %r5,%r12 */
+ EMIT2(0x165c);
+ break;
+ case BPF_S_ALU_OR_K: /* A |= K */
+ /* o %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5650d000, EMIT_CONST(K));
+ break;
+ case BPF_S_ALU_LSH_X: /* A <<= X; */
+ jit->seen |= SEEN_XREG;
+ /* sll %r5,0(%r12) */
+ EMIT4(0x8950c000);
+ break;
+ case BPF_S_ALU_LSH_K: /* A <<= K */
+ if (K == 0)
+ break;
+ /* sll %r5,K */
+ EMIT4_DISP(0x89500000, K);
+ break;
+ case BPF_S_ALU_RSH_X: /* A >>= X; */
+ jit->seen |= SEEN_XREG;
+ /* srl %r5,0(%r12) */
+ EMIT4(0x8850c000);
+ break;
+ case BPF_S_ALU_RSH_K: /* A >>= K; */
+ if (K == 0)
+ break;
+ /* srl %r5,K */
+ EMIT4_DISP(0x88500000, K);
+ break;
+ case BPF_S_ALU_NEG: /* A = -A */
+ /* lnr %r5,%r5 */
+ EMIT2(0x1155);
+ break;
+ case BPF_S_JMP_JA: /* ip += K */
+ offset = addrs[i + K] + jit->start - jit->prg;
+ EMIT4_PCREL(0xa7f40000, offset);
+ break;
+ case BPF_S_JMP_JGT_K: /* ip += (A > K) ? jt : jf */
+ mask = 0x200000; /* jh */
+ goto kbranch;
+ case BPF_S_JMP_JGE_K: /* ip += (A >= K) ? jt : jf */
+ mask = 0xa00000; /* jhe */
+ goto kbranch;
+ case BPF_S_JMP_JEQ_K: /* ip += (A == K) ? jt : jf */
+ mask = 0x800000; /* je */
+kbranch: /* Emit compare if the branch targets are different */
+ if (filter->jt != filter->jf) {
+ if (K <= 16383)
+ /* chi %r5,<K> */
+ EMIT4_IMM(0xa75e0000, K);
+ else
+ /* c %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5950d000, 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);
+ 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);
+ }
+ break;
+ case BPF_S_JMP_JSET_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_S_JMP_JGT_X: /* ip += (A > X) ? jt : jf */
+ mask = 0x200000; /* jh */
+ goto xbranch;
+ case BPF_S_JMP_JGE_X: /* ip += (A >= X) ? jt : jf */
+ mask = 0xa00000; /* jhe */
+ goto xbranch;
+ case BPF_S_JMP_JEQ_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;
+ /* cr %r5,%r12 */
+ EMIT2(0x195c);
+ }
+ goto branch;
+ case BPF_S_JMP_JSET_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);
+ }
+ goto branch;
+ case BPF_S_LD_W_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_S_LD_H_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_S_LD_B_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_S_LD_W_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_S_LD_H_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_S_LD_B_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_S_LDX_B_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));
+ break;
+ }
+ jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH;
+ offset = jit->off_load_bmsh;
+ goto call_fn;
+ case BPF_S_LD_W_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_S_LDX_W_LEN: /* X = skb->len; */
+ jit->seen |= SEEN_XREG;
+ /* l %r12,<d(len)>(%r2) */
+ EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len));
+ break;
+ case BPF_S_LD_IMM: /* A = K */
+ if (K <= 16383)
+ /* lhi %r5,K */
+ EMIT4_IMM(0xa7580000, K);
+ else
+ /* l %r5,<d(K)>(%r13) */
+ EMIT4_DISP(0x5850d000, EMIT_CONST(K));
+ break;
+ case BPF_S_LDX_IMM: /* X = K */
+ jit->seen |= SEEN_XREG;
+ if (K <= 16383)
+ /* lhi %r12,<K> */
+ EMIT4_IMM(0xa7c80000, K);
+ else
+ /* l %r12,<d(K)>(%r13) */
+ EMIT4_DISP(0x58c0d000, EMIT_CONST(K));
+ break;
+ case BPF_S_LD_MEM: /* A = mem[K] */
+ jit->seen |= SEEN_MEM;
+ /* l %r5,<K>(%r15) */
+ EMIT4_DISP(0x5850f000,
+ (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
+ break;
+ case BPF_S_LDX_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_S_MISC_TAX: /* X = A */
+ jit->seen |= SEEN_XREG;
+ /* lr %r12,%r5 */
+ EMIT2(0x18c5);
+ break;
+ case BPF_S_MISC_TXA: /* A = X */
+ jit->seen |= SEEN_XREG;
+ /* lr %r5,%r12 */
+ EMIT2(0x185c);
+ break;
+ case BPF_S_RET_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_S_RET_A:
+ /* llgfr %r2,%r5 */
+ EMIT4(0xb9160025);
+ /* j <exit> */
+ EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
+ break;
+ case BPF_S_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_S_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_S_ANC_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_S_ANC_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_S_ANC_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_S_ANC_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_S_ANC_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_S_ANC_RXHASH: /* A = skb->rxhash */
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, rxhash) != 4);
+ /* l %r5,<d(rxhash)>(%r2) */
+ EMIT4_DISP(0x58502000, offsetof(struct sk_buff, rxhash));
+ break;
+ case BPF_S_ANC_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
+ break;
+ default: /* too complex, give up */
+ goto out;
+ }
+ addrs[i] = jit->prg - jit->start;
+ return 0;
+out:
+ return -1;
+}
+
+void bpf_jit_compile(struct sk_filter *fp)
+{
+ unsigned long size, prg_len, lit_len;
+ struct bpf_jit jit, cjit;
+ unsigned int *addrs;
+ int pass, i;
+
+ if (!bpf_jit_enable)
+ return;
+ addrs = kmalloc(fp->len * sizeof(*addrs), GFP_KERNEL);
+ if (addrs == NULL)
+ return;
+ memset(addrs, 0, fp->len * sizeof(*addrs));
+ 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 = max_t(unsigned long, prg_len + lit_len,
+ sizeof(struct work_struct));
+ if (size >= BPF_SIZE_MAX)
+ goto out;
+ jit.start = module_alloc(size);
+ if (!jit.start)
+ 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;
+ }
+ if (bpf_jit_enable > 1) {
+ pr_err("flen=%d proglen=%lu pass=%d image=%p\n",
+ fp->len, jit.end - jit.start, pass, jit.start);
+ if (jit.start) {
+ printk(KERN_ERR "JIT code:\n");
+ print_fn_code(jit.start, jit.mid - jit.start);
+ print_hex_dump(KERN_ERR, "JIT literals:\n",
+ DUMP_PREFIX_ADDRESS, 16, 1,
+ jit.mid, jit.end - jit.mid, false);
+ }
+ }
+ if (jit.start)
+ fp->bpf_func = (void *) jit.start;
+out:
+ kfree(addrs);
+}
+
+static void jit_free_defer(struct work_struct *arg)
+{
+ module_free(NULL, arg);
+}
+
+/* run from softirq, we must use a work_struct to call
+ * module_free() from process context
+ */
+void bpf_jit_free(struct sk_filter *fp)
+{
+ struct work_struct *work;
+
+ if (fp->bpf_func == sk_run_filter)
+ return;
+ work = (struct work_struct *)fp->bpf_func;
+ INIT_WORK(work, jit_free_defer);
+ schedule_work(work);
+}
projects / karo-tx-linux.git / commitdiff