- 根目录:
- arch
- sparc
- net
- bpf_jit_comp.c
#include <linux/moduleloader.h>
#include <linux/workqueue.h>
#include <linux/netdevice.h>
#include <linux/filter.h>
#include <linux/cache.h>
#include <linux/if_vlan.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 XOR F3(2, 0x03)
#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_and(R1, R2, R3) \
*prog++ = (AND | RS1(R1) | RS2(R2) | RD(R3))
#define emit_andi(R1, IMM, R3) \
*prog++ = (AND | 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_VLAN_TAG:
case BPF_S_ANC_VLAN_TAG_PRESENT:
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_ANC_ALU_XOR_X: /* A ^= X; */
case BPF_S_ALU_XOR_X:
emit_alu_X(XOR);
break;
case BPF_S_ALU_XOR_K: /* A ^= K */
emit_alu_K(XOR, 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_ANC_VLAN_TAG:
case BPF_S_ANC_VLAN_TAG_PRESENT:
emit_skb_load16(vlan_tci, r_A);
if (filter[i].code == BPF_S_ANC_VLAN_TAG) {
emit_andi(r_A, VLAN_VID_MASK, r_A);
} else {
emit_loadimm(VLAN_TAG_PRESENT, r_TMP);
emit_and(r_A, r_TMP, 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)
bpf_jit_dump(flen, proglen, pass, image);
if (image) {
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);
}
}