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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/powerpc/net/bpf_jit_comp32.c

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34 KiB
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// SPDX-License-Identifier: GPL-2.0-only
/*
* eBPF JIT compiler for PPC32
*
* Copyright 2020 Christophe Leroy <christophe.leroy@csgroup.eu>
* CS GROUP France
*
* Based on PPC64 eBPF JIT compiler by Naveen N. Rao
*/
#include <linux/moduleloader.h>
#include <asm/cacheflush.h>
#include <asm/asm-compat.h>
#include <linux/netdevice.h>
#include <linux/filter.h>
#include <linux/if_vlan.h>
#include <asm/kprobes.h>
#include <linux/bpf.h>
#include "bpf_jit.h"
/*
* Stack layout:
*
* [ prev sp ] <-------------
* [ nv gpr save area ] 16 * 4 |
* fp (r31) --> [ ebpf stack space ] upto 512 |
* [ frame header ] 16 |
* sp (r1) ---> [ stack pointer ] --------------
*/
/* for gpr non volatile registers r17 to r31 (14) + tail call */
#define BPF_PPC_STACK_SAVE (15 * 4 + 4)
/* stack frame, ensure this is quadword aligned */
#define BPF_PPC_STACKFRAME(ctx) (STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_SAVE + (ctx)->stack_size)
/* BPF register usage */
#define TMP_REG (MAX_BPF_JIT_REG + 0)
/* BPF to ppc register mappings */
const int b2p[MAX_BPF_JIT_REG + 1] = {
/* function return value */
[BPF_REG_0] = 12,
/* function arguments */
[BPF_REG_1] = 4,
[BPF_REG_2] = 6,
[BPF_REG_3] = 8,
[BPF_REG_4] = 10,
[BPF_REG_5] = 22,
/* non volatile registers */
[BPF_REG_6] = 24,
[BPF_REG_7] = 26,
[BPF_REG_8] = 28,
[BPF_REG_9] = 30,
/* frame pointer aka BPF_REG_10 */
[BPF_REG_FP] = 18,
/* eBPF jit internal registers */
[BPF_REG_AX] = 20,
[TMP_REG] = 31, /* 32 bits */
};
static int bpf_to_ppc(struct codegen_context *ctx, int reg)
{
return ctx->b2p[reg];
}
/* PPC NVR range -- update this if we ever use NVRs below r17 */
#define BPF_PPC_NVR_MIN 17
#define BPF_PPC_TC 16
static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
{
if ((reg >= BPF_PPC_NVR_MIN && reg < 32) || reg == BPF_PPC_TC)
return BPF_PPC_STACKFRAME(ctx) - 4 * (32 - reg);
WARN(true, "BPF JIT is asking about unknown registers, will crash the stack");
/* Use the hole we have left for alignment */
return BPF_PPC_STACKFRAME(ctx) - 4;
}
void bpf_jit_realloc_regs(struct codegen_context *ctx)
{
if (ctx->seen & SEEN_FUNC)
return;
while (ctx->seen & SEEN_NVREG_MASK &&
(ctx->seen & SEEN_VREG_MASK) != SEEN_VREG_MASK) {
int old = 32 - fls(ctx->seen & (SEEN_NVREG_MASK & 0xaaaaaaab));
int new = 32 - fls(~ctx->seen & (SEEN_VREG_MASK & 0xaaaaaaaa));
int i;
for (i = BPF_REG_0; i <= TMP_REG; i++) {
if (ctx->b2p[i] != old)
continue;
ctx->b2p[i] = new;
bpf_set_seen_register(ctx, new);
bpf_clear_seen_register(ctx, old);
if (i != TMP_REG) {
bpf_set_seen_register(ctx, new - 1);
bpf_clear_seen_register(ctx, old - 1);
}
break;
}
}
}
void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
{
int i;
/* First arg comes in as a 32 bits pointer. */
EMIT(PPC_RAW_MR(bpf_to_ppc(ctx, BPF_REG_1), _R3));
EMIT(PPC_RAW_LI(bpf_to_ppc(ctx, BPF_REG_1) - 1, 0));
EMIT(PPC_RAW_STWU(_R1, _R1, -BPF_PPC_STACKFRAME(ctx)));
/*
* Initialize tail_call_cnt in stack frame if we do tail calls.
* Otherwise, put in NOPs so that it can be skipped when we are
* invoked through a tail call.
*/
if (ctx->seen & SEEN_TAILCALL)
EMIT(PPC_RAW_STW(bpf_to_ppc(ctx, BPF_REG_1) - 1, _R1,
bpf_jit_stack_offsetof(ctx, BPF_PPC_TC)));
else
EMIT(PPC_RAW_NOP());
#define BPF_TAILCALL_PROLOGUE_SIZE 16
/*
* We need a stack frame, but we don't necessarily need to
* save/restore LR unless we call other functions
*/
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_MFLR(_R0));
/*
* Back up non-volatile regs -- registers r18-r31
*/
for (i = BPF_PPC_NVR_MIN; i <= 31; i++)
if (bpf_is_seen_register(ctx, i))
EMIT(PPC_RAW_STW(i, _R1, bpf_jit_stack_offsetof(ctx, i)));
/* If needed retrieve arguments 9 and 10, ie 5th 64 bits arg.*/
if (bpf_is_seen_register(ctx, bpf_to_ppc(ctx, BPF_REG_5))) {
EMIT(PPC_RAW_LWZ(bpf_to_ppc(ctx, BPF_REG_5) - 1, _R1, BPF_PPC_STACKFRAME(ctx)) + 8);
EMIT(PPC_RAW_LWZ(bpf_to_ppc(ctx, BPF_REG_5), _R1, BPF_PPC_STACKFRAME(ctx)) + 12);
}
/* Setup frame pointer to point to the bpf stack area */
if (bpf_is_seen_register(ctx, bpf_to_ppc(ctx, BPF_REG_FP))) {
EMIT(PPC_RAW_LI(bpf_to_ppc(ctx, BPF_REG_FP) - 1, 0));
EMIT(PPC_RAW_ADDI(bpf_to_ppc(ctx, BPF_REG_FP), _R1,
STACK_FRAME_MIN_SIZE + ctx->stack_size));
}
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_STW(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF));
}
static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
{
int i;
/* Restore NVRs */
for (i = BPF_PPC_NVR_MIN; i <= 31; i++)
if (bpf_is_seen_register(ctx, i))
EMIT(PPC_RAW_LWZ(i, _R1, bpf_jit_stack_offsetof(ctx, i)));
}
void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
{
EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(ctx, BPF_REG_0)));
bpf_jit_emit_common_epilogue(image, ctx);
/* Tear down our stack frame */
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF));
EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME(ctx)));
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_MTLR(_R0));
EMIT(PPC_RAW_BLR());
}
void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func)
{
s32 rel = (s32)func - (s32)(image + ctx->idx);
if (image && rel < 0x2000000 && rel >= -0x2000000) {
PPC_BL_ABS(func);
EMIT(PPC_RAW_NOP());
EMIT(PPC_RAW_NOP());
EMIT(PPC_RAW_NOP());
} else {
/* Load function address into r0 */
EMIT(PPC_RAW_LIS(_R0, IMM_H(func)));
EMIT(PPC_RAW_ORI(_R0, _R0, IMM_L(func)));
EMIT(PPC_RAW_MTCTR(_R0));
EMIT(PPC_RAW_BCTRL());
}
}
static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
{
/*
* By now, the eBPF program has already setup parameters in r3-r6
* r3-r4/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
* r5-r6/BPF_REG_2 - pointer to bpf_array
* r7-r8/BPF_REG_3 - index in bpf_array
*/
int b2p_bpf_array = bpf_to_ppc(ctx, BPF_REG_2);
int b2p_index = bpf_to_ppc(ctx, BPF_REG_3);
/*
* if (index >= array->map.max_entries)
* goto out;
*/
EMIT(PPC_RAW_LWZ(_R0, b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
EMIT(PPC_RAW_CMPLW(b2p_index, _R0));
EMIT(PPC_RAW_LWZ(_R0, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC)));
PPC_BCC(COND_GE, out);
/*
* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
* goto out;
*/
EMIT(PPC_RAW_CMPLWI(_R0, MAX_TAIL_CALL_CNT));
/* tail_call_cnt++; */
EMIT(PPC_RAW_ADDIC(_R0, _R0, 1));
PPC_BCC(COND_GT, out);
/* prog = array->ptrs[index]; */
EMIT(PPC_RAW_RLWINM(_R3, b2p_index, 2, 0, 29));
EMIT(PPC_RAW_ADD(_R3, _R3, b2p_bpf_array));
EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_array, ptrs)));
EMIT(PPC_RAW_STW(_R0, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC)));
/*
* if (prog == NULL)
* goto out;
*/
EMIT(PPC_RAW_CMPLWI(_R3, 0));
PPC_BCC(COND_EQ, out);
/* goto *(prog->bpf_func + prologue_size); */
EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_prog, bpf_func)));
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF));
EMIT(PPC_RAW_ADDIC(_R3, _R3, BPF_TAILCALL_PROLOGUE_SIZE));
if (ctx->seen & SEEN_FUNC)
EMIT(PPC_RAW_MTLR(_R0));
EMIT(PPC_RAW_MTCTR(_R3));
EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(ctx, BPF_REG_1)));
/* tear restore NVRs, ... */
bpf_jit_emit_common_epilogue(image, ctx);
EMIT(PPC_RAW_BCTR());
/* out: */
return 0;
}
/* Assemble the body code between the prologue & epilogue */
int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
u32 *addrs, bool extra_pass)
{
const struct bpf_insn *insn = fp->insnsi;
int flen = fp->len;
int i, ret;
/* Start of epilogue code - will only be valid 2nd pass onwards */
u32 exit_addr = addrs[flen];
for (i = 0; i < flen; i++) {
u32 code = insn[i].code;
u32 dst_reg = bpf_to_ppc(ctx, insn[i].dst_reg);
u32 dst_reg_h = dst_reg - 1;
u32 src_reg = bpf_to_ppc(ctx, insn[i].src_reg);
u32 src_reg_h = src_reg - 1;
u32 tmp_reg = bpf_to_ppc(ctx, TMP_REG);
s16 off = insn[i].off;
s32 imm = insn[i].imm;
bool func_addr_fixed;
u64 func_addr;
u32 true_cond;
u32 tmp_idx;
int j;
/*
* addrs[] maps a BPF bytecode address into a real offset from
* the start of the body code.
*/
addrs[i] = ctx->idx * 4;
/*
* As an optimization, we note down which registers
* are used so that we can only save/restore those in our
* prologue and epilogue. We do this here regardless of whether
* the actual BPF instruction uses src/dst registers or not
* (for instance, BPF_CALL does not use them). The expectation
* is that those instructions will have src_reg/dst_reg set to
* 0. Even otherwise, we just lose some prologue/epilogue
* optimization but everything else should work without
* any issues.
*/
if (dst_reg >= 3 && dst_reg < 32) {
bpf_set_seen_register(ctx, dst_reg);
bpf_set_seen_register(ctx, dst_reg_h);
}
if (src_reg >= 3 && src_reg < 32) {
bpf_set_seen_register(ctx, src_reg);
bpf_set_seen_register(ctx, src_reg_h);
}
switch (code) {
/*
* Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
*/
case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
EMIT(PPC_RAW_ADDC(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_ADDE(dst_reg_h, dst_reg_h, src_reg_h));
break;
case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
EMIT(PPC_RAW_SUBFC(dst_reg, src_reg, dst_reg));
EMIT(PPC_RAW_SUBFE(dst_reg_h, src_reg_h, dst_reg_h));
break;
case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
imm = -imm;
fallthrough;
case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
if (IMM_HA(imm) & 0xffff)
EMIT(PPC_RAW_ADDIS(dst_reg, dst_reg, IMM_HA(imm)));
if (IMM_L(imm))
EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
break;
case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
imm = -imm;
fallthrough;
case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
if (!imm)
break;
if (imm >= -32768 && imm < 32768) {
EMIT(PPC_RAW_ADDIC(dst_reg, dst_reg, imm));
} else {
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_ADDC(dst_reg, dst_reg, _R0));
}
if (imm >= 0 || (BPF_OP(code) == BPF_SUB && imm == 0x80000000))
EMIT(PPC_RAW_ADDZE(dst_reg_h, dst_reg_h));
else
EMIT(PPC_RAW_ADDME(dst_reg_h, dst_reg_h));
break;
case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
bpf_set_seen_register(ctx, tmp_reg);
EMIT(PPC_RAW_MULW(_R0, dst_reg, src_reg_h));
EMIT(PPC_RAW_MULW(dst_reg_h, dst_reg_h, src_reg));
EMIT(PPC_RAW_MULHWU(tmp_reg, dst_reg, src_reg));
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, _R0));
EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, tmp_reg));
break;
case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
if (imm >= -32768 && imm < 32768) {
EMIT(PPC_RAW_MULI(dst_reg, dst_reg, imm));
} else {
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, _R0));
}
break;
case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
if (!imm) {
PPC_LI32(dst_reg, 0);
PPC_LI32(dst_reg_h, 0);
break;
}
if (imm == 1)
break;
if (imm == -1) {
EMIT(PPC_RAW_SUBFIC(dst_reg, dst_reg, 0));
EMIT(PPC_RAW_SUBFZE(dst_reg_h, dst_reg_h));
break;
}
bpf_set_seen_register(ctx, tmp_reg);
PPC_LI32(tmp_reg, imm);
EMIT(PPC_RAW_MULW(dst_reg_h, dst_reg_h, tmp_reg));
if (imm < 0)
EMIT(PPC_RAW_SUB(dst_reg_h, dst_reg_h, dst_reg));
EMIT(PPC_RAW_MULHWU(_R0, dst_reg, tmp_reg));
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp_reg));
EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, _R0));
break;
case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
EMIT(PPC_RAW_DIVWU(_R0, dst_reg, src_reg));
EMIT(PPC_RAW_MULW(_R0, src_reg, _R0));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, _R0));
break;
case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
return -EOPNOTSUPP;
case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
return -EOPNOTSUPP;
case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
if (!imm)
return -EINVAL;
if (imm == 1)
break;
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, _R0));
break;
case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
if (!imm)
return -EINVAL;
if (!is_power_of_2((u32)imm)) {
bpf_set_seen_register(ctx, tmp_reg);
PPC_LI32(tmp_reg, imm);
EMIT(PPC_RAW_DIVWU(_R0, dst_reg, tmp_reg));
EMIT(PPC_RAW_MULW(_R0, tmp_reg, _R0));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, _R0));
break;
}
if (imm == 1)
EMIT(PPC_RAW_LI(dst_reg, 0));
else
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 32 - ilog2((u32)imm), 31));
break;
case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
if (!imm)
return -EINVAL;
if (imm < 0)
imm = -imm;
if (!is_power_of_2(imm))
return -EOPNOTSUPP;
if (imm == 1)
EMIT(PPC_RAW_LI(dst_reg, 0));
else
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 32 - ilog2(imm), 31));
EMIT(PPC_RAW_LI(dst_reg_h, 0));
break;
case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
if (!imm)
return -EINVAL;
if (!is_power_of_2(abs(imm)))
return -EOPNOTSUPP;
if (imm < 0) {
EMIT(PPC_RAW_SUBFIC(dst_reg, dst_reg, 0));
EMIT(PPC_RAW_SUBFZE(dst_reg_h, dst_reg_h));
imm = -imm;
}
if (imm == 1)
break;
imm = ilog2(imm);
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 32 - imm, imm, 31));
EMIT(PPC_RAW_RLWIMI(dst_reg, dst_reg_h, 32 - imm, 0, imm - 1));
EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg_h, imm));
break;
case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
break;
case BPF_ALU64 | BPF_NEG: /* dst = -dst */
EMIT(PPC_RAW_SUBFIC(dst_reg, dst_reg, 0));
EMIT(PPC_RAW_SUBFZE(dst_reg_h, dst_reg_h));
break;
/*
* Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
*/
case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_AND(dst_reg_h, dst_reg_h, src_reg_h));
break;
case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
if (imm >= 0)
EMIT(PPC_RAW_LI(dst_reg_h, 0));
fallthrough;
case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
if (!IMM_H(imm)) {
EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
} else if (!IMM_L(imm)) {
EMIT(PPC_RAW_ANDIS(dst_reg, dst_reg, IMM_H(imm)));
} else if (imm == (((1 << fls(imm)) - 1) ^ ((1 << (ffs(i) - 1)) - 1))) {
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0,
32 - fls(imm), 32 - ffs(imm)));
} else {
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_AND(dst_reg, dst_reg, _R0));
}
break;
case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, src_reg_h));
break;
case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
/* Sign-extended */
if (imm < 0)
EMIT(PPC_RAW_LI(dst_reg_h, -1));
fallthrough;
case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
if (IMM_L(imm))
EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
if (IMM_H(imm))
EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
break;
case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
if (dst_reg == src_reg) {
EMIT(PPC_RAW_LI(dst_reg, 0));
EMIT(PPC_RAW_LI(dst_reg_h, 0));
} else {
EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_XOR(dst_reg_h, dst_reg_h, src_reg_h));
}
break;
case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
if (dst_reg == src_reg)
EMIT(PPC_RAW_LI(dst_reg, 0));
else
EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
if (imm < 0)
EMIT(PPC_RAW_NOR(dst_reg_h, dst_reg_h, dst_reg_h));
fallthrough;
case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
if (IMM_L(imm))
EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
if (IMM_H(imm))
EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
break;
case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
bpf_set_seen_register(ctx, tmp_reg);
EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32));
EMIT(PPC_RAW_SLW(dst_reg_h, dst_reg_h, src_reg));
EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32));
EMIT(PPC_RAW_SRW(_R0, dst_reg, _R0));
EMIT(PPC_RAW_SLW(tmp_reg, dst_reg, tmp_reg));
EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, _R0));
EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, tmp_reg));
break;
case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<= (u32) imm */
if (!imm)
break;
EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
break;
case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<= imm */
if (imm < 0)
return -EINVAL;
if (!imm)
break;
if (imm < 32) {
EMIT(PPC_RAW_RLWINM(dst_reg_h, dst_reg_h, imm, 0, 31 - imm));
EMIT(PPC_RAW_RLWIMI(dst_reg_h, dst_reg, imm, 32 - imm, 31));
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, imm, 0, 31 - imm));
break;
}
if (imm < 64)
EMIT(PPC_RAW_RLWINM(dst_reg_h, dst_reg, imm, 0, 31 - imm));
else
EMIT(PPC_RAW_LI(dst_reg_h, 0));
EMIT(PPC_RAW_LI(dst_reg, 0));
break;
case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
bpf_set_seen_register(ctx, tmp_reg);
EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32));
EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32));
EMIT(PPC_RAW_SLW(_R0, dst_reg_h, _R0));
EMIT(PPC_RAW_SRW(tmp_reg, dst_reg_h, tmp_reg));
EMIT(PPC_RAW_OR(dst_reg, dst_reg, _R0));
EMIT(PPC_RAW_SRW(dst_reg_h, dst_reg_h, src_reg));
EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg));
break;
case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
if (!imm)
break;
EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
break;
case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
if (imm < 0)
return -EINVAL;
if (!imm)
break;
if (imm < 32) {
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 32 - imm, imm, 31));
EMIT(PPC_RAW_RLWIMI(dst_reg, dst_reg_h, 32 - imm, 0, imm - 1));
EMIT(PPC_RAW_RLWINM(dst_reg_h, dst_reg_h, 32 - imm, imm, 31));
break;
}
if (imm < 64)
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg_h, 64 - imm, imm - 32, 31));
else
EMIT(PPC_RAW_LI(dst_reg, 0));
EMIT(PPC_RAW_LI(dst_reg_h, 0));
break;
case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
bpf_set_seen_register(ctx, tmp_reg);
EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32));
EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
EMIT(PPC_RAW_SLW(_R0, dst_reg_h, _R0));
EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32));
EMIT(PPC_RAW_OR(dst_reg, dst_reg, _R0));
EMIT(PPC_RAW_RLWINM(_R0, tmp_reg, 0, 26, 26));
EMIT(PPC_RAW_SRAW(tmp_reg, dst_reg_h, tmp_reg));
EMIT(PPC_RAW_SRAW(dst_reg_h, dst_reg_h, src_reg));
EMIT(PPC_RAW_SLW(tmp_reg, tmp_reg, _R0));
EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg));
break;
case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
if (!imm)
break;
EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
break;
case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
if (imm < 0)
return -EINVAL;
if (!imm)
break;
if (imm < 32) {
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 32 - imm, imm, 31));
EMIT(PPC_RAW_RLWIMI(dst_reg, dst_reg_h, 32 - imm, 0, imm - 1));
EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg_h, imm));
break;
}
if (imm < 64)
EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg_h, imm - 32));
else
EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg_h, 31));
EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg_h, 31));
break;
/*
* MOV
*/
case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
if (dst_reg == src_reg)
break;
EMIT(PPC_RAW_MR(dst_reg, src_reg));
EMIT(PPC_RAW_MR(dst_reg_h, src_reg_h));
break;
case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
/* special mov32 for zext */
if (imm == 1)
EMIT(PPC_RAW_LI(dst_reg_h, 0));
else if (dst_reg != src_reg)
EMIT(PPC_RAW_MR(dst_reg, src_reg));
break;
case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
PPC_LI32(dst_reg, imm);
PPC_EX32(dst_reg_h, imm);
break;
case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
PPC_LI32(dst_reg, imm);
break;
/*
* BPF_FROM_BE/LE
*/
case BPF_ALU | BPF_END | BPF_FROM_LE:
switch (imm) {
case 16:
/* Copy 16 bits to upper part */
EMIT(PPC_RAW_RLWIMI(dst_reg, dst_reg, 16, 0, 15));
/* Rotate 8 bits right & mask */
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 24, 16, 31));
break;
case 32:
/*
* Rotate word left by 8 bits:
* 2 bytes are already in their final position
* -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
*/
EMIT(PPC_RAW_RLWINM(_R0, dst_reg, 8, 0, 31));
/* Rotate 24 bits and insert byte 1 */
EMIT(PPC_RAW_RLWIMI(_R0, dst_reg, 24, 0, 7));
/* Rotate 24 bits and insert byte 3 */
EMIT(PPC_RAW_RLWIMI(_R0, dst_reg, 24, 16, 23));
EMIT(PPC_RAW_MR(dst_reg, _R0));
break;
case 64:
bpf_set_seen_register(ctx, tmp_reg);
EMIT(PPC_RAW_RLWINM(tmp_reg, dst_reg, 8, 0, 31));
EMIT(PPC_RAW_RLWINM(_R0, dst_reg_h, 8, 0, 31));
/* Rotate 24 bits and insert byte 1 */
EMIT(PPC_RAW_RLWIMI(tmp_reg, dst_reg, 24, 0, 7));
EMIT(PPC_RAW_RLWIMI(_R0, dst_reg_h, 24, 0, 7));
/* Rotate 24 bits and insert byte 3 */
EMIT(PPC_RAW_RLWIMI(tmp_reg, dst_reg, 24, 16, 23));
EMIT(PPC_RAW_RLWIMI(_R0, dst_reg_h, 24, 16, 23));
EMIT(PPC_RAW_MR(dst_reg, _R0));
EMIT(PPC_RAW_MR(dst_reg_h, tmp_reg));
break;
}
break;
case BPF_ALU | BPF_END | BPF_FROM_BE:
switch (imm) {
case 16:
/* zero-extend 16 bits into 32 bits */
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 16, 31));
break;
case 32:
case 64:
/* nop */
break;
}
break;
/*
* BPF_ST NOSPEC (speculation barrier)
*/
case BPF_ST | BPF_NOSPEC:
break;
/*
* BPF_ST(X)
*/
case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
break;
case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_STB(_R0, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
break;
case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_STH(_R0, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
break;
case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_STW(_R0, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
EMIT(PPC_RAW_STW(src_reg_h, dst_reg, off));
EMIT(PPC_RAW_STW(src_reg, dst_reg, off + 4));
break;
case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_STW(_R0, dst_reg, off + 4));
PPC_EX32(_R0, imm);
EMIT(PPC_RAW_STW(_R0, dst_reg, off));
break;
/*
* BPF_STX ATOMIC (atomic ops)
*/
case BPF_STX | BPF_ATOMIC | BPF_W:
if (imm != BPF_ADD) {
pr_err_ratelimited("eBPF filter atomic op code %02x (@%d) unsupported\n",
code, i);
return -ENOTSUPP;
}
/* *(u32 *)(dst + off) += src */
bpf_set_seen_register(ctx, tmp_reg);
/* Get offset into TMP_REG */
EMIT(PPC_RAW_LI(tmp_reg, off));
/* load value from memory into r0 */
EMIT(PPC_RAW_LWARX(_R0, tmp_reg, dst_reg, 0));
/* add value from src_reg into this */
EMIT(PPC_RAW_ADD(_R0, _R0, src_reg));
/* store result back */
EMIT(PPC_RAW_STWCX(_R0, tmp_reg, dst_reg));
/* we're done if this succeeded */
PPC_BCC_SHORT(COND_NE, (ctx->idx - 3) * 4);
break;
case BPF_STX | BPF_ATOMIC | BPF_DW: /* *(u64 *)(dst + off) += src */
return -EOPNOTSUPP;
/*
* BPF_LDX
*/
case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
if (!fp->aux->verifier_zext)
EMIT(PPC_RAW_LI(dst_reg_h, 0));
break;
case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
if (!fp->aux->verifier_zext)
EMIT(PPC_RAW_LI(dst_reg_h, 0));
break;
case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
if (!fp->aux->verifier_zext)
EMIT(PPC_RAW_LI(dst_reg_h, 0));
break;
case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off));
EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4));
break;
/*
* Doubleword load
* 16 byte instruction that uses two 'struct bpf_insn'
*/
case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
tmp_idx = ctx->idx;
PPC_LI32(dst_reg_h, (u32)insn[i + 1].imm);
PPC_LI32(dst_reg, (u32)insn[i].imm);
/* padding to allow full 4 instructions for later patching */
for (j = ctx->idx - tmp_idx; j < 4; j++)
EMIT(PPC_RAW_NOP());
/* Adjust for two bpf instructions */
addrs[++i] = ctx->idx * 4;
break;
/*
* Return/Exit
*/
case BPF_JMP | BPF_EXIT:
/*
* If this isn't the very last instruction, branch to
* the epilogue. If we _are_ the last instruction,
* we'll just fall through to the epilogue.
*/
if (i != flen - 1)
PPC_JMP(exit_addr);
/* else fall through to the epilogue */
break;
/*
* Call kernel helper or bpf function
*/
case BPF_JMP | BPF_CALL:
ctx->seen |= SEEN_FUNC;
ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass,
&func_addr, &func_addr_fixed);
if (ret < 0)
return ret;
if (bpf_is_seen_register(ctx, bpf_to_ppc(ctx, BPF_REG_5))) {
EMIT(PPC_RAW_STW(bpf_to_ppc(ctx, BPF_REG_5) - 1, _R1, 8));
EMIT(PPC_RAW_STW(bpf_to_ppc(ctx, BPF_REG_5), _R1, 12));
}
bpf_jit_emit_func_call_rel(image, ctx, func_addr);
EMIT(PPC_RAW_MR(bpf_to_ppc(ctx, BPF_REG_0) - 1, _R3));
EMIT(PPC_RAW_MR(bpf_to_ppc(ctx, BPF_REG_0), _R4));
break;
/*
* Jumps and branches
*/
case BPF_JMP | BPF_JA:
PPC_JMP(addrs[i + 1 + off]);
break;
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP32 | BPF_JGT | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_X:
case BPF_JMP32 | BPF_JSGT | BPF_K:
case BPF_JMP32 | BPF_JSGT | BPF_X:
true_cond = COND_GT;
goto cond_branch;
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JLT | BPF_K:
case BPF_JMP32 | BPF_JLT | BPF_X:
case BPF_JMP32 | BPF_JSLT | BPF_K:
case BPF_JMP32 | BPF_JSLT | BPF_X:
true_cond = COND_LT;
goto cond_branch;
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JGE | BPF_K:
case BPF_JMP32 | BPF_JGE | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSGE | BPF_X:
true_cond = COND_GE;
goto cond_branch;
case BPF_JMP | BPF_JLE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP32 | BPF_JLE | BPF_K:
case BPF_JMP32 | BPF_JLE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_X:
true_cond = COND_LE;
goto cond_branch;
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JEQ | BPF_X:
true_cond = COND_EQ;
goto cond_branch;
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JNE | BPF_X:
true_cond = COND_NE;
goto cond_branch;
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP | BPF_JSET | BPF_X:
case BPF_JMP32 | BPF_JSET | BPF_K:
case BPF_JMP32 | BPF_JSET | BPF_X:
true_cond = COND_NE;
/* fallthrough; */
cond_branch:
switch (code) {
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP | BPF_JNE | BPF_X:
/* unsigned comparison */
EMIT(PPC_RAW_CMPLW(dst_reg_h, src_reg_h));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
break;
case BPF_JMP32 | BPF_JGT | BPF_X:
case BPF_JMP32 | BPF_JLT | BPF_X:
case BPF_JMP32 | BPF_JGE | BPF_X:
case BPF_JMP32 | BPF_JLE | BPF_X:
case BPF_JMP32 | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_X:
/* unsigned comparison */
EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
break;
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
/* signed comparison */
EMIT(PPC_RAW_CMPW(dst_reg_h, src_reg_h));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
break;
case BPF_JMP32 | BPF_JSGT | BPF_X:
case BPF_JMP32 | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_X:
/* signed comparison */
EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
break;
case BPF_JMP | BPF_JSET | BPF_X:
EMIT(PPC_RAW_AND_DOT(_R0, dst_reg_h, src_reg_h));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, src_reg));
break;
case BPF_JMP32 | BPF_JSET | BPF_X: {
EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, src_reg));
break;
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_K:
/*
* Need sign-extended load, so only positive
* values can be used as imm in cmplwi
*/
if (imm >= 0 && imm < 32768) {
EMIT(PPC_RAW_CMPLWI(dst_reg_h, 0));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
} else {
/* sign-extending load ... but unsigned comparison */
PPC_EX32(_R0, imm);
EMIT(PPC_RAW_CMPLW(dst_reg_h, _R0));
PPC_LI32(_R0, imm);
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLW(dst_reg, _R0));
}
break;
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_K:
case BPF_JMP32 | BPF_JLT | BPF_K:
case BPF_JMP32 | BPF_JGE | BPF_K:
case BPF_JMP32 | BPF_JLE | BPF_K:
if (imm >= 0 && imm < 65536) {
EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
} else {
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_CMPLW(dst_reg, _R0));
}
break;
}
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_K:
if (imm >= 0 && imm < 65536) {
EMIT(PPC_RAW_CMPWI(dst_reg_h, imm < 0 ? -1 : 0));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
} else {
/* sign-extending load */
EMIT(PPC_RAW_CMPWI(dst_reg_h, imm < 0 ? -1 : 0));
PPC_LI32(_R0, imm);
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
EMIT(PPC_RAW_CMPLW(dst_reg, _R0));
}
break;
case BPF_JMP32 | BPF_JSGT | BPF_K:
case BPF_JMP32 | BPF_JSLT | BPF_K:
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_K:
/*
* signed comparison, so any 16-bit value
* can be used in cmpwi
*/
if (imm >= -32768 && imm < 32768) {
EMIT(PPC_RAW_CMPWI(dst_reg, imm));
} else {
/* sign-extending load */
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_CMPW(dst_reg, _R0));
}
break;
case BPF_JMP | BPF_JSET | BPF_K:
/* andi does not sign-extend the immediate */
if (imm >= 0 && imm < 32768) {
/* PPC_ANDI is _only/always_ dot-form */
EMIT(PPC_RAW_ANDI(_R0, dst_reg, imm));
} else {
PPC_LI32(_R0, imm);
if (imm < 0) {
EMIT(PPC_RAW_CMPWI(dst_reg_h, 0));
PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4);
}
EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, _R0));
}
break;
case BPF_JMP32 | BPF_JSET | BPF_K:
/* andi does not sign-extend the immediate */
if (imm >= 0 && imm < 32768) {
/* PPC_ANDI is _only/always_ dot-form */
EMIT(PPC_RAW_ANDI(_R0, dst_reg, imm));
} else {
PPC_LI32(_R0, imm);
EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, _R0));
}
break;
}
PPC_BCC(true_cond, addrs[i + 1 + off]);
break;
/*
* Tail call
*/
case BPF_JMP | BPF_TAIL_CALL:
ctx->seen |= SEEN_TAILCALL;
ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
if (ret < 0)
return ret;
break;
default:
/*
* The filter contains something cruel & unusual.
* We don't handle it, but also there shouldn't be
* anything missing from our list.
*/
pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", code, i);
return -EOPNOTSUPP;
}
if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext &&
!insn_is_zext(&insn[i + 1]) && !(BPF_OP(code) == BPF_END && imm == 64))
EMIT(PPC_RAW_LI(dst_reg_h, 0));
}
/* Set end-of-body-code address for exit. */
addrs[i] = ctx->idx * 4;
return 0;
}
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