static void bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func)
{
unsigned int i, ctx_idx = ctx->idx;
/* Load function address into r12 */
PPC_LI64(12, func);
/* For bpf-to-bpf function calls, the callee's address is unknown
* until the last extra pass. As seen above, we use PPC_LI64() to
* load the callee's address, but this may optimize the number of
* instructions required based on the nature of the address.
*
* Since we don't want the number of instructions emitted to change,
* we pad the optimized PPC_LI64() call with NOPs to guarantee that
* we always have a five-instruction sequence, which is the maximum
* that PPC_LI64() can emit.
*/
for (i = ctx->idx - ctx_idx; i < 5; i++)
PPC_NOP();
#ifdef PPC64_ELF_ABI_v1
/*
* Load TOC from function descriptor at offset 8.
* We can clobber r2 since we get called through a
* function pointer (so caller will save/restore r2)
* and since we don't use a TOC ourself.
*/
PPC_BPF_LL(2, 12, 8);
/* Load actual entry point from function descriptor */
PPC_BPF_LL(12, 12, 0);
#endif
PPC_MTLR(12);
PPC_BLRL();
}
static void bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx,
u64 func)
{
#ifdef PPC64_ELF_ABI_v1
/* func points to the function descriptor */
PPC_LI64(b2p[TMP_REG_2], func);
/* Load actual entry point from function descriptor */
PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_2], 0);
/* ... and move it to LR */
PPC_MTLR(b2p[TMP_REG_1]);
/*
* Load TOC from function descriptor at offset 8.
* We can clobber r2 since we get called through a
* function pointer (so caller will save/restore r2)
* and since we don't use a TOC ourself.
*/
PPC_BPF_LL(2, b2p[TMP_REG_2], 8);
#else
/* We can clobber r12 */
PPC_FUNC_ADDR(12, func);
PPC_MTLR(12);
#endif
PPC_BLRL();
}
/* Assemble the body code between the prologue & epilogue. */
static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
struct codegen_context *ctx,
unsigned int *addrs)
{
const struct sock_filter *filter = fp->insns;
int flen = fp->len;
u8 *func;
unsigned int true_cond;
int i;
/* Start of epilogue code */
unsigned int exit_addr = addrs[flen];
for (i = 0; i < flen; i++) {
unsigned int K = filter[i].k;
u16 code = bpf_anc_helper(&filter[i]);
/*
* addrs[] maps a BPF bytecode address into a real offset from
* the start of the body code.
*/
addrs[i] = ctx->idx * 4;
switch (code) {
/*** ALU ops ***/
case BPF_ALU | BPF_ADD | BPF_X: /* A += X; */
ctx->seen |= SEEN_XREG;
PPC_ADD(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_ADD | BPF_K: /* A += K; */
if (!K)
break;
PPC_ADDI(r_A, r_A, IMM_L(K));
if (K >= 32768)
PPC_ADDIS(r_A, r_A, IMM_HA(K));
break;
case BPF_ALU | BPF_SUB | BPF_X: /* A -= X; */
ctx->seen |= SEEN_XREG;
PPC_SUB(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_SUB | BPF_K: /* A -= K */
if (!K)
break;
PPC_ADDI(r_A, r_A, IMM_L(-K));
if (K >= 32768)
PPC_ADDIS(r_A, r_A, IMM_HA(-K));
break;
case BPF_ALU | BPF_MUL | BPF_X: /* A *= X; */
ctx->seen |= SEEN_XREG;
PPC_MUL(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_MUL | BPF_K: /* A *= K */
if (K < 32768)
PPC_MULI(r_A, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_MUL(r_A, r_A, r_scratch1);
}
break;
case BPF_ALU | BPF_MOD | BPF_X: /* A %= X; */
ctx->seen |= SEEN_XREG;
PPC_CMPWI(r_X, 0);
if (ctx->pc_ret0 != -1) {
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
} else {
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
PPC_LI(r_ret, 0);
PPC_JMP(exit_addr);
}
PPC_DIVWU(r_scratch1, r_A, r_X);
PPC_MUL(r_scratch1, r_X, r_scratch1);
PPC_SUB(r_A, r_A, r_scratch1);
break;
case BPF_ALU | BPF_MOD | BPF_K: /* A %= K; */
PPC_LI32(r_scratch2, K);
PPC_DIVWU(r_scratch1, r_A, r_scratch2);
PPC_MUL(r_scratch1, r_scratch2, r_scratch1);
PPC_SUB(r_A, r_A, r_scratch1);
break;
case BPF_ALU | BPF_DIV | BPF_X: /* A /= X; */
ctx->seen |= SEEN_XREG;
PPC_CMPWI(r_X, 0);
if (ctx->pc_ret0 != -1) {
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
} else {
/*
* Exit, returning 0; first pass hits here
* (longer worst-case code size).
*/
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
PPC_LI(r_ret, 0);
PPC_JMP(exit_addr);
}
PPC_DIVWU(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_DIV | BPF_K: /* A /= K */
if (K == 1)
break;
PPC_LI32(r_scratch1, K);
PPC_DIVWU(r_A, r_A, r_scratch1);
break;
case BPF_ALU | BPF_AND | BPF_X:
ctx->seen |= SEEN_XREG;
PPC_AND(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_AND | BPF_K:
if (!IMM_H(K))
PPC_ANDI(r_A, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_AND(r_A, r_A, r_scratch1);
}
break;
case BPF_ALU | BPF_OR | BPF_X:
ctx->seen |= SEEN_XREG;
PPC_OR(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_OR | BPF_K:
if (IMM_L(K))
PPC_ORI(r_A, r_A, IMM_L(K));
if (K >= 65536)
PPC_ORIS(r_A, r_A, IMM_H(K));
break;
case BPF_ANC | SKF_AD_ALU_XOR_X:
case BPF_ALU | BPF_XOR | BPF_X: /* A ^= X */
ctx->seen |= SEEN_XREG;
PPC_XOR(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_XOR | BPF_K: /* A ^= K */
if (IMM_L(K))
PPC_XORI(r_A, r_A, IMM_L(K));
if (K >= 65536)
PPC_XORIS(r_A, r_A, IMM_H(K));
break;
case BPF_ALU | BPF_LSH | BPF_X: /* A <<= X; */
ctx->seen |= SEEN_XREG;
PPC_SLW(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_LSH | BPF_K:
if (K == 0)
break;
else
PPC_SLWI(r_A, r_A, K);
break;
case BPF_ALU | BPF_RSH | BPF_X: /* A >>= X; */
ctx->seen |= SEEN_XREG;
PPC_SRW(r_A, r_A, r_X);
break;
case BPF_ALU | BPF_RSH | BPF_K: /* A >>= K; */
if (K == 0)
break;
else
PPC_SRWI(r_A, r_A, K);
break;
case BPF_ALU | BPF_NEG:
PPC_NEG(r_A, r_A);
break;
case BPF_RET | BPF_K:
PPC_LI32(r_ret, K);
if (!K) {
if (ctx->pc_ret0 == -1)
ctx->pc_ret0 = i;
}
/*
* If this isn't the very last instruction, branch to
* the epilogue if we've stuff to clean up. Otherwise,
* if there's nothing to tidy, just return. If we /are/
* the last instruction, we're about to fall through to
* the epilogue to return.
*/
if (i != flen - 1) {
/*
* Note: 'seen' is properly valid only on pass
* #2. Both parts of this conditional are the
* same instruction size though, meaning the
* first pass will still correctly determine the
* code size/addresses.
*/
if (ctx->seen)
PPC_JMP(exit_addr);
else
PPC_BLR();
}
break;
case BPF_RET | BPF_A:
PPC_MR(r_ret, r_A);
if (i != flen - 1) {
if (ctx->seen)
PPC_JMP(exit_addr);
else
PPC_BLR();
}
break;
case BPF_MISC | BPF_TAX: /* X = A */
PPC_MR(r_X, r_A);
break;
case BPF_MISC | BPF_TXA: /* A = X */
ctx->seen |= SEEN_XREG;
PPC_MR(r_A, r_X);
break;
/*** Constant loads/M[] access ***/
case BPF_LD | BPF_IMM: /* A = K */
PPC_LI32(r_A, K);
break;
case BPF_LDX | BPF_IMM: /* X = K */
PPC_LI32(r_X, K);
break;
case BPF_LD | BPF_MEM: /* A = mem[K] */
PPC_MR(r_A, r_M + (K & 0xf));
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_LDX | BPF_MEM: /* X = mem[K] */
PPC_MR(r_X, r_M + (K & 0xf));
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_ST: /* mem[K] = A */
PPC_MR(r_M + (K & 0xf), r_A);
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_STX: /* mem[K] = X */
PPC_MR(r_M + (K & 0xf), r_X);
ctx->seen |= SEEN_XREG | SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_LD | BPF_W | BPF_LEN: /* A = skb->len; */
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, len));
break;
case BPF_LDX | BPF_W | BPF_LEN: /* X = skb->len; */
PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff, len));
break;
/*** Ancillary info loads ***/
case BPF_ANC | SKF_AD_PROTOCOL: /* A = ntohs(skb->protocol); */
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
protocol) != 2);
PPC_NTOHS_OFFS(r_A, r_skb, offsetof(struct sk_buff,
protocol));
break;
case BPF_ANC | SKF_AD_IFINDEX:
PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
dev));
PPC_CMPDI(r_scratch1, 0);
if (ctx->pc_ret0 != -1) {
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
} else {
/* Exit, returning 0; first pass hits here. */
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
PPC_LI(r_ret, 0);
PPC_JMP(exit_addr);
}
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
ifindex) != 4);
PPC_LWZ_OFFS(r_A, r_scratch1,
offsetof(struct net_device, ifindex));
break;
case BPF_ANC | SKF_AD_MARK:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
mark));
break;
case BPF_ANC | SKF_AD_RXHASH:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
PPC_LWZ_OFFS(r_A, r_skb, 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);
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
vlan_tci));
if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
PPC_ANDI(r_A, r_A, ~VLAN_TAG_PRESENT);
} else {
PPC_ANDI(r_A, r_A, VLAN_TAG_PRESENT);
PPC_SRWI(r_A, r_A, 12);
}
break;
case BPF_ANC | SKF_AD_QUEUE:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
queue_mapping) != 2);
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
queue_mapping));
break;
case BPF_ANC | SKF_AD_CPU:
#ifdef CONFIG_SMP
/*
* PACA ptr is r13:
* raw_smp_processor_id() = local_paca->paca_index
*/
BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct,
paca_index) != 2);
PPC_LHZ_OFFS(r_A, 13,
offsetof(struct paca_struct, paca_index));
#else
PPC_LI(r_A, 0);
#endif
break;
/*** Absolute loads from packet header/data ***/
case BPF_LD | BPF_W | BPF_ABS:
func = CHOOSE_LOAD_FUNC(K, sk_load_word);
goto common_load;
case BPF_LD | BPF_H | BPF_ABS:
func = CHOOSE_LOAD_FUNC(K, sk_load_half);
goto common_load;
case BPF_LD | BPF_B | BPF_ABS:
func = CHOOSE_LOAD_FUNC(K, sk_load_byte);
common_load:
/* Load from [K]. */
ctx->seen |= SEEN_DATAREF;
PPC_LI64(r_scratch1, func);
PPC_MTLR(r_scratch1);
PPC_LI32(r_addr, K);
PPC_BLRL();
/*
* Helper returns 'lt' condition on error, and an
* appropriate return value in r3
*/
PPC_BCC(COND_LT, exit_addr);
break;
/*** Indirect loads from packet header/data ***/
case BPF_LD | BPF_W | BPF_IND:
func = sk_load_word;
goto common_load_ind;
case BPF_LD | BPF_H | BPF_IND:
func = sk_load_half;
goto common_load_ind;
case BPF_LD | BPF_B | BPF_IND:
func = sk_load_byte;
common_load_ind:
/*
* Load from [X + K]. Negative offsets are tested for
* in the helper functions.
*/
ctx->seen |= SEEN_DATAREF | SEEN_XREG;
PPC_LI64(r_scratch1, func);
PPC_MTLR(r_scratch1);
PPC_ADDI(r_addr, r_X, IMM_L(K));
if (K >= 32768)
PPC_ADDIS(r_addr, r_addr, IMM_HA(K));
PPC_BLRL();
/* If error, cr0.LT set */
PPC_BCC(COND_LT, exit_addr);
break;
case BPF_LDX | BPF_B | BPF_MSH:
func = CHOOSE_LOAD_FUNC(K, sk_load_byte_msh);
goto common_load;
break;
/*** Jump and branches ***/
case BPF_JMP | BPF_JA:
if (K != 0)
PPC_JMP(addrs[i + 1 + K]);
break;
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGT | BPF_X:
true_cond = COND_GT;
goto cond_branch;
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JGE | BPF_X:
true_cond = COND_GE;
goto cond_branch;
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JEQ | BPF_X:
true_cond = COND_EQ;
goto cond_branch;
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP | BPF_JSET | BPF_X:
true_cond = COND_NE;
/* Fall through */
cond_branch:
/* same targets, can avoid doing the test :) */
if (filter[i].jt == filter[i].jf) {
if (filter[i].jt > 0)
PPC_JMP(addrs[i + 1 + filter[i].jt]);
break;
}
switch (code) {
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JEQ | BPF_X:
ctx->seen |= SEEN_XREG;
PPC_CMPLW(r_A, r_X);
break;
case BPF_JMP | BPF_JSET | BPF_X:
ctx->seen |= SEEN_XREG;
PPC_AND_DOT(r_scratch1, r_A, r_X);
break;
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
if (K < 32768)
PPC_CMPLWI(r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_CMPLW(r_A, r_scratch1);
}
break;
case BPF_JMP | BPF_JSET | BPF_K:
if (K < 32768)
/* PPC_ANDI is /only/ dot-form */
PPC_ANDI(r_scratch1, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_AND_DOT(r_scratch1, r_A,
r_scratch1);
}
break;
}
/* Sometimes branches are constructed "backward", with
* the false path being the branch and true path being
* a fallthrough to the next instruction.
*/
if (filter[i].jt == 0)
/* Swap the sense of the branch */
PPC_BCC(true_cond ^ COND_CMP_TRUE,
addrs[i + 1 + filter[i].jf]);
else {
PPC_BCC(true_cond, addrs[i + 1 + filter[i].jt]);
if (filter[i].jf != 0)
PPC_JMP(addrs[i + 1 + filter[i].jf]);
}
break;
default:
/* The filter contains something cruel & unusual.
* We don't handle it, but also there shouldn't be
* anything missing from our list.
*/
if (printk_ratelimit())
pr_err("BPF filter opcode %04x (@%d) unsupported\n",
filter[i].code, i);
return -ENOTSUPP;
}
}
/* Set end-of-body-code address for exit. */
addrs[i] = ctx->idx * 4;
return 0;
}
/* Assemble the body code between the prologue & epilogue. */
static int bpf_jit_build_body(struct sk_filter *fp, u32 *image,
struct codegen_context *ctx,
unsigned int *addrs)
{
const struct sock_filter *filter = fp->insns;
int flen = fp->len;
u8 *func;
unsigned int true_cond;
int i;
/* Start of epilogue code */
unsigned int exit_addr = addrs[flen];
for (i = 0; i < flen; i++) {
unsigned int K = filter[i].k;
/*
* addrs[] maps a BPF bytecode address into a real offset from
* the start of the body code.
*/
addrs[i] = ctx->idx * 4;
switch (filter[i].code) {
/*** ALU ops ***/
case BPF_S_ALU_ADD_X: /* A += X; */
ctx->seen |= SEEN_XREG;
PPC_ADD(r_A, r_A, r_X);
break;
case BPF_S_ALU_ADD_K: /* A += K; */
if (!K)
break;
PPC_ADDI(r_A, r_A, IMM_L(K));
if (K >= 32768)
PPC_ADDIS(r_A, r_A, IMM_HA(K));
break;
case BPF_S_ALU_SUB_X: /* A -= X; */
ctx->seen |= SEEN_XREG;
PPC_SUB(r_A, r_A, r_X);
break;
case BPF_S_ALU_SUB_K: /* A -= K */
if (!K)
break;
PPC_ADDI(r_A, r_A, IMM_L(-K));
if (K >= 32768)
PPC_ADDIS(r_A, r_A, IMM_HA(-K));
break;
case BPF_S_ALU_MUL_X: /* A *= X; */
ctx->seen |= SEEN_XREG;
PPC_MUL(r_A, r_A, r_X);
break;
case BPF_S_ALU_MUL_K: /* A *= K */
if (K < 32768)
PPC_MULI(r_A, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_MUL(r_A, r_A, r_scratch1);
}
break;
case BPF_S_ALU_DIV_X: /* A /= X; */
ctx->seen |= SEEN_XREG;
PPC_CMPWI(r_X, 0);
if (ctx->pc_ret0 != -1) {
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
} else {
/*
* Exit, returning 0; first pass hits here
* (longer worst-case code size).
*/
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
PPC_LI(r_ret, 0);
PPC_JMP(exit_addr);
}
PPC_DIVWU(r_A, r_A, r_X);
break;
case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K); */
PPC_LI32(r_scratch1, K);
/* Top 32 bits of 64bit result -> A */
PPC_MULHWU(r_A, r_A, r_scratch1);
break;
case BPF_S_ALU_AND_X:
ctx->seen |= SEEN_XREG;
PPC_AND(r_A, r_A, r_X);
break;
case BPF_S_ALU_AND_K:
if (!IMM_H(K))
PPC_ANDI(r_A, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_AND(r_A, r_A, r_scratch1);
}
break;
case BPF_S_ALU_OR_X:
ctx->seen |= SEEN_XREG;
PPC_OR(r_A, r_A, r_X);
break;
case BPF_S_ALU_OR_K:
if (IMM_L(K))
PPC_ORI(r_A, r_A, IMM_L(K));
if (K >= 65536)
PPC_ORIS(r_A, r_A, IMM_H(K));
break;
case BPF_S_ALU_LSH_X: /* A <<= X; */
ctx->seen |= SEEN_XREG;
PPC_SLW(r_A, r_A, r_X);
break;
case BPF_S_ALU_LSH_K:
if (K == 0)
break;
else
PPC_SLWI(r_A, r_A, K);
break;
case BPF_S_ALU_RSH_X: /* A >>= X; */
ctx->seen |= SEEN_XREG;
PPC_SRW(r_A, r_A, r_X);
break;
case BPF_S_ALU_RSH_K: /* A >>= K; */
if (K == 0)
break;
else
PPC_SRWI(r_A, r_A, K);
break;
case BPF_S_ALU_NEG:
PPC_NEG(r_A, r_A);
break;
case BPF_S_RET_K:
PPC_LI32(r_ret, K);
if (!K) {
if (ctx->pc_ret0 == -1)
ctx->pc_ret0 = i;
}
/*
* If this isn't the very last instruction, branch to
* the epilogue if we've stuff to clean up. Otherwise,
* if there's nothing to tidy, just return. If we /are/
* the last instruction, we're about to fall through to
* the epilogue to return.
*/
if (i != flen - 1) {
/*
* Note: 'seen' is properly valid only on pass
* #2. Both parts of this conditional are the
* same instruction size though, meaning the
* first pass will still correctly determine the
* code size/addresses.
*/
if (ctx->seen)
PPC_JMP(exit_addr);
else
PPC_BLR();
}
break;
case BPF_S_RET_A:
PPC_MR(r_ret, r_A);
if (i != flen - 1) {
if (ctx->seen)
PPC_JMP(exit_addr);
else
PPC_BLR();
}
break;
case BPF_S_MISC_TAX: /* X = A */
PPC_MR(r_X, r_A);
break;
case BPF_S_MISC_TXA: /* A = X */
ctx->seen |= SEEN_XREG;
PPC_MR(r_A, r_X);
break;
/*** Constant loads/M[] access ***/
case BPF_S_LD_IMM: /* A = K */
PPC_LI32(r_A, K);
break;
case BPF_S_LDX_IMM: /* X = K */
PPC_LI32(r_X, K);
break;
case BPF_S_LD_MEM: /* A = mem[K] */
PPC_MR(r_A, r_M + (K & 0xf));
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_S_LDX_MEM: /* X = mem[K] */
PPC_MR(r_X, r_M + (K & 0xf));
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_S_ST: /* mem[K] = A */
PPC_MR(r_M + (K & 0xf), r_A);
ctx->seen |= SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_S_STX: /* mem[K] = X */
PPC_MR(r_M + (K & 0xf), r_X);
ctx->seen |= SEEN_XREG | SEEN_MEM | (1<<(K & 0xf));
break;
case BPF_S_LD_W_LEN: /* A = skb->len; */
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff, len));
break;
case BPF_S_LDX_W_LEN: /* X = skb->len; */
PPC_LWZ_OFFS(r_X, r_skb, offsetof(struct sk_buff, len));
break;
/*** Ancillary info loads ***/
/* None of the BPF_S_ANC* codes appear to be passed by
* sk_chk_filter(). The interpreter and the x86 BPF
* compiler implement them so we do too -- they may be
* planted in future.
*/
case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
protocol) != 2);
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
protocol));
/* ntohs is a NOP with BE loads. */
break;
case BPF_S_ANC_IFINDEX:
PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
dev));
PPC_CMPDI(r_scratch1, 0);
if (ctx->pc_ret0 != -1) {
PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
} else {
/* Exit, returning 0; first pass hits here. */
PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);
PPC_LI(r_ret, 0);
PPC_JMP(exit_addr);
}
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device,
ifindex) != 4);
PPC_LWZ_OFFS(r_A, r_scratch1,
offsetof(struct net_device, ifindex));
break;
case BPF_S_ANC_MARK:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
mark));
break;
case BPF_S_ANC_RXHASH:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, rxhash) != 4);
PPC_LWZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
rxhash));
break;
case BPF_S_ANC_QUEUE:
BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff,
queue_mapping) != 2);
PPC_LHZ_OFFS(r_A, r_skb, offsetof(struct sk_buff,
queue_mapping));
break;
case BPF_S_ANC_CPU:
#ifdef CONFIG_SMP
/*
* PACA ptr is r13:
* raw_smp_processor_id() = local_paca->paca_index
*/
BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct,
paca_index) != 2);
PPC_LHZ_OFFS(r_A, 13,
offsetof(struct paca_struct, paca_index));
#else
PPC_LI(r_A, 0);
#endif
break;
/*** Absolute loads from packet header/data ***/
case BPF_S_LD_W_ABS:
func = sk_load_word;
goto common_load;
case BPF_S_LD_H_ABS:
func = sk_load_half;
goto common_load;
case BPF_S_LD_B_ABS:
func = sk_load_byte;
common_load:
/*
* Load from [K]. Reference with the (negative)
* SKF_NET_OFF/SKF_LL_OFF offsets is unsupported.
*/
ctx->seen |= SEEN_DATAREF;
if ((int)K < 0)
return -ENOTSUPP;
PPC_LI64(r_scratch1, func);
PPC_MTLR(r_scratch1);
PPC_LI32(r_addr, K);
PPC_BLRL();
/*
* Helper returns 'lt' condition on error, and an
* appropriate return value in r3
*/
PPC_BCC(COND_LT, exit_addr);
break;
/*** Indirect loads from packet header/data ***/
case BPF_S_LD_W_IND:
func = sk_load_word;
goto common_load_ind;
case BPF_S_LD_H_IND:
func = sk_load_half;
goto common_load_ind;
case BPF_S_LD_B_IND:
func = sk_load_byte;
common_load_ind:
/*
* Load from [X + K]. Negative offsets are tested for
* in the helper functions, and result in a 'ret 0'.
*/
ctx->seen |= SEEN_DATAREF | SEEN_XREG;
PPC_LI64(r_scratch1, func);
PPC_MTLR(r_scratch1);
PPC_ADDI(r_addr, r_X, IMM_L(K));
if (K >= 32768)
PPC_ADDIS(r_addr, r_addr, IMM_HA(K));
PPC_BLRL();
/* If error, cr0.LT set */
PPC_BCC(COND_LT, exit_addr);
break;
case BPF_S_LDX_B_MSH:
/*
* x86 version drops packet (RET 0) when K<0, whereas
* interpreter does allow K<0 (__load_pointer, special
* ancillary data). common_load returns ENOTSUPP if K<0,
* so we fall back to interpreter & filter works.
*/
func = sk_load_byte_msh;
goto common_load;
break;
/*** Jump and branches ***/
case BPF_S_JMP_JA:
if (K != 0)
PPC_JMP(addrs[i + 1 + K]);
break;
case BPF_S_JMP_JGT_K:
case BPF_S_JMP_JGT_X:
true_cond = COND_GT;
goto cond_branch;
case BPF_S_JMP_JGE_K:
case BPF_S_JMP_JGE_X:
true_cond = COND_GE;
goto cond_branch;
case BPF_S_JMP_JEQ_K:
case BPF_S_JMP_JEQ_X:
true_cond = COND_EQ;
goto cond_branch;
case BPF_S_JMP_JSET_K:
case BPF_S_JMP_JSET_X:
true_cond = COND_NE;
/* Fall through */
cond_branch:
/* same targets, can avoid doing the test :) */
if (filter[i].jt == filter[i].jf) {
if (filter[i].jt > 0)
PPC_JMP(addrs[i + 1 + filter[i].jt]);
break;
}
switch (filter[i].code) {
case BPF_S_JMP_JGT_X:
case BPF_S_JMP_JGE_X:
case BPF_S_JMP_JEQ_X:
ctx->seen |= SEEN_XREG;
PPC_CMPLW(r_A, r_X);
break;
case BPF_S_JMP_JSET_X:
ctx->seen |= SEEN_XREG;
PPC_AND_DOT(r_scratch1, r_A, r_X);
break;
case BPF_S_JMP_JEQ_K:
case BPF_S_JMP_JGT_K:
case BPF_S_JMP_JGE_K:
if (K < 32768)
PPC_CMPLWI(r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_CMPLW(r_A, r_scratch1);
}
break;
case BPF_S_JMP_JSET_K:
if (K < 32768)
/* PPC_ANDI is /only/ dot-form */
PPC_ANDI(r_scratch1, r_A, K);
else {
PPC_LI32(r_scratch1, K);
PPC_AND_DOT(r_scratch1, r_A,
r_scratch1);
}
break;
}
/* Sometimes branches are constructed "backward", with
* the false path being the branch and true path being
* a fallthrough to the next instruction.
*/
if (filter[i].jt == 0)
/* Swap the sense of the branch */
PPC_BCC(true_cond ^ COND_CMP_TRUE,
addrs[i + 1 + filter[i].jf]);
else {
PPC_BCC(true_cond, addrs[i + 1 + filter[i].jt]);
if (filter[i].jf != 0)
PPC_JMP(addrs[i + 1 + filter[i].jf]);
}
break;
default:
/* The filter contains something cruel & unusual.
* We don't handle it, but also there shouldn't be
* anything missing from our list.
*/
if (printk_ratelimit())
pr_err("BPF filter opcode %04x (@%d) unsupported\n",
filter[i].code, i);
return -ENOTSUPP;
}
}
/* Set end-of-body-code address for exit. */
addrs[i] = ctx->idx * 4;
return 0;
}
