diff options
Diffstat (limited to 'arch/sparc/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/sparc/net/bpf_jit_comp.c | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c new file mode 100644 index 000000000000..1a69244e785b --- /dev/null +++ b/arch/sparc/net/bpf_jit_comp.c @@ -0,0 +1,802 @@ +#include <linux/moduleloader.h> +#include <linux/workqueue.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/cache.h> + +#include <asm/cacheflush.h> +#include <asm/ptrace.h> + +#include "bpf_jit.h" + +int bpf_jit_enable __read_mostly; + +static inline bool is_simm13(unsigned int value) +{ + return value + 0x1000 < 0x2000; +} + +static void bpf_flush_icache(void *start_, void *end_) +{ +#ifdef CONFIG_SPARC64 + /* Cheetah's I-cache is fully coherent. */ + if (tlb_type == spitfire) { + unsigned long start = (unsigned long) start_; + unsigned long end = (unsigned long) end_; + + start &= ~7UL; + end = (end + 7UL) & ~7UL; + while (start < end) { + flushi(start); + start += 32; + } + } +#endif +} + +#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 S13(X) ((X) & 0x1fff) +#define IMMED 0x00002000 +#define RD(X) ((X) << 25) +#define RS1(X) ((X) << 14) +#define RS2(X) ((X)) +#define OP(X) ((X) << 30) +#define OP2(X) ((X) << 22) +#define OP3(X) ((X) << 19) +#define COND(X) ((X) << 25) +#define F1(X) OP(X) +#define F2(X, Y) (OP(X) | OP2(Y)) +#define F3(X, Y) (OP(X) | OP3(Y)) + +#define CONDN COND(0x0) +#define CONDE COND(0x1) +#define CONDLE COND(0x2) +#define CONDL COND(0x3) +#define CONDLEU COND(0x4) +#define CONDCS COND(0x5) +#define CONDNEG COND(0x6) +#define CONDVC COND(0x7) +#define CONDA COND(0x8) +#define CONDNE COND(0x9) +#define CONDG COND(0xa) +#define CONDGE COND(0xb) +#define CONDGU COND(0xc) +#define CONDCC COND(0xd) +#define CONDPOS COND(0xe) +#define CONDVS COND(0xf) + +#define CONDGEU CONDCC +#define CONDLU CONDCS + +#define WDISP22(X) (((X) >> 2) & 0x3fffff) + +#define BA (F2(0, 2) | CONDA) +#define BGU (F2(0, 2) | CONDGU) +#define BLEU (F2(0, 2) | CONDLEU) +#define BGEU (F2(0, 2) | CONDGEU) +#define BLU (F2(0, 2) | CONDLU) +#define BE (F2(0, 2) | CONDE) +#define BNE (F2(0, 2) | CONDNE) + +#ifdef CONFIG_SPARC64 +#define BNE_PTR (F2(0, 1) | CONDNE | (2 << 20)) +#else +#define BNE_PTR BNE +#endif + +#define SETHI(K, REG) \ + (F2(0, 0x4) | RD(REG) | (((K) >> 10) & 0x3fffff)) +#define OR_LO(K, REG) \ + (F3(2, 0x02) | IMMED | RS1(REG) | ((K) & 0x3ff) | RD(REG)) + +#define ADD F3(2, 0x00) +#define AND F3(2, 0x01) +#define ANDCC F3(2, 0x11) +#define OR F3(2, 0x02) +#define SUB F3(2, 0x04) +#define SUBCC F3(2, 0x14) +#define MUL F3(2, 0x0a) /* umul */ +#define DIV F3(2, 0x0e) /* udiv */ +#define SLL F3(2, 0x25) +#define SRL F3(2, 0x26) +#define JMPL F3(2, 0x38) +#define CALL F1(1) +#define BR F2(0, 0x01) +#define RD_Y F3(2, 0x28) +#define WR_Y F3(2, 0x30) + +#define LD32 F3(3, 0x00) +#define LD8 F3(3, 0x01) +#define LD16 F3(3, 0x02) +#define LD64 F3(3, 0x0b) +#define ST32 F3(3, 0x04) + +#ifdef CONFIG_SPARC64 +#define LDPTR LD64 +#define BASE_STACKFRAME 176 +#else +#define LDPTR LD32 +#define BASE_STACKFRAME 96 +#endif + +#define LD32I (LD32 | IMMED) +#define LD8I (LD8 | IMMED) +#define LD16I (LD16 | IMMED) +#define LD64I (LD64 | IMMED) +#define LDPTRI (LDPTR | IMMED) +#define ST32I (ST32 | IMMED) + +#define emit_nop() \ +do { \ + *prog++ = SETHI(0, G0); \ +} while (0) + +#define emit_neg() \ +do { /* sub %g0, r_A, r_A */ \ + *prog++ = SUB | RS1(G0) | RS2(r_A) | RD(r_A); \ +} while (0) + +#define emit_reg_move(FROM, TO) \ +do { /* or %g0, FROM, TO */ \ + *prog++ = OR | RS1(G0) | RS2(FROM) | RD(TO); \ +} while (0) + +#define emit_clear(REG) \ +do { /* or %g0, %g0, REG */ \ + *prog++ = OR | RS1(G0) | RS2(G0) | RD(REG); \ +} while (0) + +#define emit_set_const(K, REG) \ +do { /* sethi %hi(K), REG */ \ + *prog++ = SETHI(K, REG); \ + /* or REG, %lo(K), REG */ \ + *prog++ = OR_LO(K, REG); \ +} while (0) + + /* Emit + * + * OP r_A, r_X, r_A + */ +#define emit_alu_X(OPCODE) \ +do { \ + seen |= SEEN_XREG; \ + *prog++ = OPCODE | RS1(r_A) | RS2(r_X) | RD(r_A); \ +} while (0) + + /* Emit either: + * + * OP r_A, K, r_A + * + * or + * + * sethi %hi(K), r_TMP + * or r_TMP, %lo(K), r_TMP + * OP r_A, r_TMP, r_A + * + * depending upon whether K fits in a signed 13-bit + * immediate instruction field. Emit nothing if K + * is zero. + */ +#define emit_alu_K(OPCODE, K) \ +do { \ + if (K) { \ + unsigned int _insn = OPCODE; \ + _insn |= RS1(r_A) | RD(r_A); \ + if (is_simm13(K)) { \ + *prog++ = _insn | IMMED | S13(K); \ + } else { \ + emit_set_const(K, r_TMP); \ + *prog++ = _insn | RS2(r_TMP); \ + } \ + } \ +} while (0) + +#define emit_loadimm(K, DEST) \ +do { \ + if (is_simm13(K)) { \ + /* or %g0, K, DEST */ \ + *prog++ = OR | IMMED | RS1(G0) | S13(K) | RD(DEST); \ + } else { \ + emit_set_const(K, DEST); \ + } \ +} while (0) + +#define emit_loadptr(BASE, STRUCT, FIELD, DEST) \ +do { unsigned int _off = offsetof(STRUCT, FIELD); \ + BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(void *)); \ + *prog++ = LDPTRI | RS1(BASE) | S13(_off) | RD(DEST); \ +} while (0) + +#define emit_load32(BASE, STRUCT, FIELD, DEST) \ +do { unsigned int _off = offsetof(STRUCT, FIELD); \ + BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u32)); \ + *prog++ = LD32I | RS1(BASE) | S13(_off) | RD(DEST); \ +} while (0) + +#define emit_load16(BASE, STRUCT, FIELD, DEST) \ +do { unsigned int _off = offsetof(STRUCT, FIELD); \ + BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u16)); \ + *prog++ = LD16I | RS1(BASE) | S13(_off) | RD(DEST); \ +} while (0) + +#define __emit_load8(BASE, STRUCT, FIELD, DEST) \ +do { unsigned int _off = offsetof(STRUCT, FIELD); \ + *prog++ = LD8I | RS1(BASE) | S13(_off) | RD(DEST); \ +} while (0) + +#define emit_load8(BASE, STRUCT, FIELD, DEST) \ +do { BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8)); \ + __emit_load8(BASE, STRUCT, FIELD, DEST); \ +} while (0) + +#define emit_ldmem(OFF, DEST) \ +do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(DEST); \ +} while (0) + +#define emit_stmem(OFF, SRC) \ +do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(SRC); \ +} while (0) + +#ifdef CONFIG_SMP +#ifdef CONFIG_SPARC64 +#define emit_load_cpu(REG) \ + emit_load16(G6, struct thread_info, cpu, REG) +#else +#define emit_load_cpu(REG) \ + emit_load32(G6, struct thread_info, cpu, REG) +#endif +#else +#define emit_load_cpu(REG) emit_clear(REG) +#endif + +#define emit_skb_loadptr(FIELD, DEST) \ + emit_loadptr(r_SKB, struct sk_buff, FIELD, DEST) +#define emit_skb_load32(FIELD, DEST) \ + emit_load32(r_SKB, struct sk_buff, FIELD, DEST) +#define emit_skb_load16(FIELD, DEST) \ + emit_load16(r_SKB, struct sk_buff, FIELD, DEST) +#define __emit_skb_load8(FIELD, DEST) \ + __emit_load8(r_SKB, struct sk_buff, FIELD, DEST) +#define emit_skb_load8(FIELD, DEST) \ + emit_load8(r_SKB, struct sk_buff, FIELD, DEST) + +#define emit_jmpl(BASE, IMM_OFF, LREG) \ + *prog++ = (JMPL | IMMED | RS1(BASE) | S13(IMM_OFF) | RD(LREG)) + +#define emit_call(FUNC) \ +do { void *_here = image + addrs[i] - 8; \ + unsigned int _off = (void *)(FUNC) - _here; \ + *prog++ = CALL | (((_off) >> 2) & 0x3fffffff); \ + emit_nop(); \ +} while (0) + +#define emit_branch(BR_OPC, DEST) \ +do { unsigned int _here = addrs[i] - 8; \ + *prog++ = BR_OPC | WDISP22((DEST) - _here); \ +} while (0) + +#define emit_branch_off(BR_OPC, OFF) \ +do { *prog++ = BR_OPC | WDISP22(OFF); \ +} while (0) + +#define emit_jump(DEST) emit_branch(BA, DEST) + +#define emit_read_y(REG) *prog++ = RD_Y | RD(REG) +#define emit_write_y(REG) *prog++ = WR_Y | IMMED | RS1(REG) | S13(0) + +#define emit_cmp(R1, R2) \ + *prog++ = (SUBCC | RS1(R1) | RS2(R2) | RD(G0)) + +#define emit_cmpi(R1, IMM) \ + *prog++ = (SUBCC | IMMED | RS1(R1) | S13(IMM) | RD(G0)); + +#define emit_btst(R1, R2) \ + *prog++ = (ANDCC | RS1(R1) | RS2(R2) | RD(G0)) + +#define emit_btsti(R1, IMM) \ + *prog++ = (ANDCC | IMMED | RS1(R1) | S13(IMM) | RD(G0)); + +#define emit_sub(R1, R2, R3) \ + *prog++ = (SUB | RS1(R1) | RS2(R2) | RD(R3)) + +#define emit_subi(R1, IMM, R3) \ + *prog++ = (SUB | IMMED | RS1(R1) | S13(IMM) | RD(R3)) + +#define emit_add(R1, R2, R3) \ + *prog++ = (ADD | RS1(R1) | RS2(R2) | RD(R3)) + +#define emit_addi(R1, IMM, R3) \ + *prog++ = (ADD | IMMED | RS1(R1) | S13(IMM) | RD(R3)) + +#define emit_alloc_stack(SZ) \ + *prog++ = (SUB | IMMED | RS1(SP) | S13(SZ) | RD(SP)) + +#define emit_release_stack(SZ) \ + *prog++ = (ADD | IMMED | RS1(SP) | S13(SZ) | RD(SP)) + +/* A note about branch offset calculations. The addrs[] array, + * indexed by BPF instruction, records the address after all the + * sparc instructions emitted for that BPF instruction. + * + * The most common case is to emit a branch at the end of such + * a code sequence. So this would be two instructions, the + * branch and it's delay slot. + * + * Therefore by default the branch emitters calculate the branch + * offset field as: + * + * destination - (addrs[i] - 8) + * + * This "addrs[i] - 8" is the address of the branch itself or + * what "." would be in assembler notation. The "8" part is + * how we take into consideration the branch and it's delay + * slot mentioned above. + * + * Sometimes we need to emit a branch earlier in the code + * sequence. And in these situations we adjust "destination" + * to accomodate this difference. For example, if we needed + * to emit a branch (and it's delay slot) right before the + * final instruction emitted for a BPF opcode, we'd use + * "destination + 4" instead of just plain "destination" above. + * + * This is why you see all of these funny emit_branch() and + * emit_jump() calls with adjusted offsets. + */ + +void bpf_jit_compile(struct sk_filter *fp) +{ + unsigned int cleanup_addr, proglen, oldproglen = 0; + u32 temp[8], *prog, *func, seen = 0, pass; + const struct sock_filter *filter = fp->insns; + int i, flen = fp->len, pc_ret0 = -1; + unsigned int *addrs; + void *image; + + if (!bpf_jit_enable) + return; + + addrs = kmalloc(flen * sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) + return; + + /* Before first pass, make a rough estimation of addrs[] + * each bpf instruction is translated to less than 64 bytes + */ + for (proglen = 0, i = 0; i < flen; i++) { + proglen += 64; + addrs[i] = proglen; + } + cleanup_addr = proglen; /* epilogue address */ + image = NULL; + for (pass = 0; pass < 10; pass++) { + u8 seen_or_pass0 = (pass == 0) ? (SEEN_XREG | SEEN_DATAREF | SEEN_MEM) : seen; + + /* no prologue/epilogue for trivial filters (RET something) */ + proglen = 0; + prog = temp; + + /* Prologue */ + if (seen_or_pass0) { + if (seen_or_pass0 & SEEN_MEM) { + unsigned int sz = BASE_STACKFRAME; + sz += BPF_MEMWORDS * sizeof(u32); + emit_alloc_stack(sz); + } + + /* Make sure we dont leek kernel memory. */ + if (seen_or_pass0 & SEEN_XREG) + emit_clear(r_X); + + /* If this filter needs to access skb data, + * load %o4 and %o5 with: + * %o4 = skb->len - skb->data_len + * %o5 = skb->data + * And also back up %o7 into r_saved_O7 so we can + * invoke the stubs using 'call'. + */ + if (seen_or_pass0 & SEEN_DATAREF) { + emit_load32(r_SKB, struct sk_buff, len, r_HEADLEN); + emit_load32(r_SKB, struct sk_buff, data_len, r_TMP); + emit_sub(r_HEADLEN, r_TMP, r_HEADLEN); + emit_loadptr(r_SKB, struct sk_buff, data, r_SKB_DATA); + } + } + emit_reg_move(O7, r_saved_O7); + + switch (filter[0].code) { + case BPF_S_RET_K: + case BPF_S_LD_W_LEN: + case BPF_S_ANC_PROTOCOL: + case BPF_S_ANC_PKTTYPE: + case BPF_S_ANC_IFINDEX: + case BPF_S_ANC_MARK: + case BPF_S_ANC_RXHASH: + case BPF_S_ANC_CPU: + case BPF_S_ANC_QUEUE: + case BPF_S_LD_W_ABS: + case BPF_S_LD_H_ABS: + case BPF_S_LD_B_ABS: + /* The first instruction sets the A register (or is + * a "RET 'constant'") + */ + break; + default: + /* Make sure we dont leak kernel information to the + * user. + */ + emit_clear(r_A); /* A = 0 */ + } + + for (i = 0; i < flen; i++) { + unsigned int K = filter[i].k; + unsigned int t_offset; + unsigned int f_offset; + u32 t_op, f_op; + int ilen; + + switch (filter[i].code) { + case BPF_S_ALU_ADD_X: /* A += X; */ + emit_alu_X(ADD); + break; + case BPF_S_ALU_ADD_K: /* A += K; */ + emit_alu_K(ADD, K); + break; + case BPF_S_ALU_SUB_X: /* A -= X; */ + emit_alu_X(SUB); + break; + case BPF_S_ALU_SUB_K: /* A -= K */ + emit_alu_K(SUB, K); + break; + case BPF_S_ALU_AND_X: /* A &= X */ + emit_alu_X(AND); + break; + case BPF_S_ALU_AND_K: /* A &= K */ + emit_alu_K(AND, K); + break; + case BPF_S_ALU_OR_X: /* A |= X */ + emit_alu_X(OR); + break; + case BPF_S_ALU_OR_K: /* A |= K */ + emit_alu_K(OR, K); + break; + case BPF_S_ALU_LSH_X: /* A <<= X */ + emit_alu_X(SLL); + break; + case BPF_S_ALU_LSH_K: /* A <<= K */ + emit_alu_K(SLL, K); + break; + case BPF_S_ALU_RSH_X: /* A >>= X */ + emit_alu_X(SRL); + break; + case BPF_S_ALU_RSH_K: /* A >>= K */ + emit_alu_K(SRL, K); + break; + case BPF_S_ALU_MUL_X: /* A *= X; */ + emit_alu_X(MUL); + break; + case BPF_S_ALU_MUL_K: /* A *= K */ + emit_alu_K(MUL, K); + break; + case BPF_S_ALU_DIV_K: /* A /= K */ + emit_alu_K(MUL, K); + emit_read_y(r_A); + break; + case BPF_S_ALU_DIV_X: /* A /= X; */ + emit_cmpi(r_X, 0); + if (pc_ret0 > 0) { + t_offset = addrs[pc_ret0 - 1]; +#ifdef CONFIG_SPARC32 + emit_branch(BE, t_offset + 20); +#else + emit_branch(BE, t_offset + 8); +#endif + emit_nop(); /* delay slot */ + } else { + emit_branch_off(BNE, 16); + emit_nop(); +#ifdef CONFIG_SPARC32 + emit_jump(cleanup_addr + 20); +#else + emit_jump(cleanup_addr + 8); +#endif + emit_clear(r_A); + } + emit_write_y(G0); +#ifdef CONFIG_SPARC32 + /* The Sparc v8 architecture requires + * three instructions between a %y + * register write and the first use. + */ + emit_nop(); + emit_nop(); + emit_nop(); +#endif + emit_alu_X(DIV); + break; + case BPF_S_ALU_NEG: + emit_neg(); + break; + case BPF_S_RET_K: + if (!K) { + if (pc_ret0 == -1) + pc_ret0 = i; + emit_clear(r_A); + } else { + emit_loadimm(K, r_A); + } + /* Fallthrough */ + case BPF_S_RET_A: + if (seen_or_pass0) { + if (i != flen - 1) { + emit_jump(cleanup_addr); + emit_nop(); + break; + } + if (seen_or_pass0 & SEEN_MEM) { + unsigned int sz = BASE_STACKFRAME; + sz += BPF_MEMWORDS * sizeof(u32); + emit_release_stack(sz); + } + } + /* jmpl %r_saved_O7 + 8, %g0 */ + emit_jmpl(r_saved_O7, 8, G0); + emit_reg_move(r_A, O0); /* delay slot */ + break; + case BPF_S_MISC_TAX: + seen |= SEEN_XREG; + emit_reg_move(r_A, r_X); + break; + case BPF_S_MISC_TXA: + seen |= SEEN_XREG; + emit_reg_move(r_X, r_A); + break; + case BPF_S_ANC_CPU: + emit_load_cpu(r_A); + break; + case BPF_S_ANC_PROTOCOL: + emit_skb_load16(protocol, r_A); + break; +#if 0 + /* GCC won't let us take the address of + * a bit field even though we very much + * know what we are doing here. + */ + case BPF_S_ANC_PKTTYPE: + __emit_skb_load8(pkt_type, r_A); + emit_alu_K(SRL, 5); + break; +#endif + case BPF_S_ANC_IFINDEX: + emit_skb_loadptr(dev, r_A); + emit_cmpi(r_A, 0); + emit_branch(BNE_PTR, cleanup_addr + 4); + emit_nop(); + emit_load32(r_A, struct net_device, ifindex, r_A); + break; + case BPF_S_ANC_MARK: + emit_skb_load32(mark, r_A); + break; + case BPF_S_ANC_QUEUE: + emit_skb_load16(queue_mapping, r_A); + break; + case BPF_S_ANC_HATYPE: + emit_skb_loadptr(dev, r_A); + emit_cmpi(r_A, 0); + emit_branch(BNE_PTR, cleanup_addr + 4); + emit_nop(); + emit_load16(r_A, struct net_device, type, r_A); + break; + case BPF_S_ANC_RXHASH: + emit_skb_load32(rxhash, r_A); + break; + + case BPF_S_LD_IMM: + emit_loadimm(K, r_A); + break; + case BPF_S_LDX_IMM: + emit_loadimm(K, r_X); + break; + case BPF_S_LD_MEM: + emit_ldmem(K * 4, r_A); + break; + case BPF_S_LDX_MEM: + emit_ldmem(K * 4, r_X); + break; + case BPF_S_ST: + emit_stmem(K * 4, r_A); + break; + case BPF_S_STX: + emit_stmem(K * 4, r_X); + break; + +#define CHOOSE_LOAD_FUNC(K, func) \ + ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) + + case BPF_S_LD_W_ABS: + func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_word); +common_load: seen |= SEEN_DATAREF; + emit_loadimm(K, r_OFF); + emit_call(func); + break; + case BPF_S_LD_H_ABS: + func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_half); + goto common_load; + case BPF_S_LD_B_ABS: + func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte); + goto common_load; + case BPF_S_LDX_B_MSH: + func = CHOOSE_LOAD_FUNC(K, bpf_jit_load_byte_msh); + goto common_load; + case BPF_S_LD_W_IND: + func = bpf_jit_load_word; +common_load_ind: seen |= SEEN_DATAREF | SEEN_XREG; + if (K) { + if (is_simm13(K)) { + emit_addi(r_X, K, r_OFF); + } else { + emit_loadimm(K, r_TMP); + emit_add(r_X, r_TMP, r_OFF); + } + } else { + emit_reg_move(r_X, r_OFF); + } + emit_call(func); + break; + case BPF_S_LD_H_IND: + func = bpf_jit_load_half; + goto common_load_ind; + case BPF_S_LD_B_IND: + func = bpf_jit_load_byte; + goto common_load_ind; + case BPF_S_JMP_JA: + emit_jump(addrs[i + K]); + emit_nop(); + break; + +#define COND_SEL(CODE, TOP, FOP) \ + case CODE: \ + t_op = TOP; \ + f_op = FOP; \ + goto cond_branch + + COND_SEL(BPF_S_JMP_JGT_K, BGU, BLEU); + COND_SEL(BPF_S_JMP_JGE_K, BGEU, BLU); + COND_SEL(BPF_S_JMP_JEQ_K, BE, BNE); + COND_SEL(BPF_S_JMP_JSET_K, BNE, BE); + COND_SEL(BPF_S_JMP_JGT_X, BGU, BLEU); + COND_SEL(BPF_S_JMP_JGE_X, BGEU, BLU); + COND_SEL(BPF_S_JMP_JEQ_X, BE, BNE); + COND_SEL(BPF_S_JMP_JSET_X, BNE, BE); + +cond_branch: f_offset = addrs[i + filter[i].jf]; + t_offset = addrs[i + filter[i].jt]; + + /* same targets, can avoid doing the test :) */ + if (filter[i].jt == filter[i].jf) { + emit_jump(t_offset); + emit_nop(); + break; + } + + switch (filter[i].code) { + case BPF_S_JMP_JGT_X: + case BPF_S_JMP_JGE_X: + case BPF_S_JMP_JEQ_X: + seen |= SEEN_XREG; + emit_cmp(r_A, r_X); + break; + case BPF_S_JMP_JSET_X: + seen |= SEEN_XREG; + emit_btst(r_A, r_X); + break; + case BPF_S_JMP_JEQ_K: + case BPF_S_JMP_JGT_K: + case BPF_S_JMP_JGE_K: + if (is_simm13(K)) { + emit_cmpi(r_A, K); + } else { + emit_loadimm(K, r_TMP); + emit_cmp(r_A, r_TMP); + } + break; + case BPF_S_JMP_JSET_K: + if (is_simm13(K)) { + emit_btsti(r_A, K); + } else { + emit_loadimm(K, r_TMP); + emit_btst(r_A, r_TMP); + } + break; + } + if (filter[i].jt != 0) { + if (filter[i].jf) + t_offset += 8; + emit_branch(t_op, t_offset); + emit_nop(); /* delay slot */ + if (filter[i].jf) { + emit_jump(f_offset); + emit_nop(); + } + break; + } + emit_branch(f_op, f_offset); + emit_nop(); /* delay slot */ + break; + + default: + /* hmm, too complex filter, give up with jit compiler */ + goto out; + } + ilen = (void *) prog - (void *) temp; + if (image) { + if (unlikely(proglen + ilen > oldproglen)) { + pr_err("bpb_jit_compile fatal error\n"); + kfree(addrs); + module_free(NULL, image); + return; + } + memcpy(image + proglen, temp, ilen); + } + proglen += ilen; + addrs[i] = proglen; + prog = temp; + } + /* last bpf instruction is always a RET : + * use it to give the cleanup instruction(s) addr + */ + cleanup_addr = proglen - 8; /* jmpl; mov r_A,%o0; */ + if (seen_or_pass0 & SEEN_MEM) + cleanup_addr -= 4; /* add %sp, X, %sp; */ + + if (image) { + if (proglen != oldproglen) + pr_err("bpb_jit_compile proglen=%u != oldproglen=%u\n", + proglen, oldproglen); + break; + } + if (proglen == oldproglen) { + image = module_alloc(max_t(unsigned int, + proglen, + sizeof(struct work_struct))); + if (!image) + goto out; + } + oldproglen = proglen; + } + + if (bpf_jit_enable > 1) + pr_err("flen=%d proglen=%u pass=%d image=%p\n", + flen, proglen, pass, image); + + if (image) { + if (bpf_jit_enable > 1) + print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_ADDRESS, + 16, 1, image, proglen, false); + bpf_flush_icache(image, image + proglen); + fp->bpf_func = (void *)image; + } +out: + kfree(addrs); + return; +} + +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) +{ + if (fp->bpf_func != sk_run_filter) { + struct work_struct *work = (struct work_struct *)fp->bpf_func; + + INIT_WORK(work, jit_free_defer); + schedule_work(work); + } +} |