[PATCH 3/4] arm64: bpf: Split the read and write halves of dst

From: Palmer Dabbelt
Date: Mon Jan 27 2020 - 21:15:07 EST

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This patch is intended to change no functionality, it just allows me to do
register renaming later.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
---
arch/arm64/net/bpf_jit_comp.c | 107 +++++++++++++++++-----------------
1 file changed, 54 insertions(+), 53 deletions(-)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 8eee68705056..fba5b1b00cd7 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -348,7 +348,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
bool extra_pass)
{
const u8 code = insn->code;
- const u8 dst = bpf2a64(ctx, insn->dst_reg);
+ const u8 dstw = bpf2a64(ctx, insn->dst_reg);
+ const u8 dstr = bpf2a64(ctx, insn->dst_reg);
const u8 src = bpf2a64(ctx, insn->src_reg);
const u8 tmp = bpf2a64(ctx, TMP_REG_1);
const u8 tmp2 = bpf2a64(ctx, TMP_REG_2);
@@ -377,32 +378,32 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
/* dst = src */
case BPF_ALU | BPF_MOV | BPF_X:
case BPF_ALU64 | BPF_MOV | BPF_X:
- emit(A64_MOV(is64, dst, src), ctx);
+ emit(A64_MOV(is64, dstw, src), ctx);
break;
/* dst = dst OP src */
case BPF_ALU | BPF_ADD | BPF_X:
case BPF_ALU64 | BPF_ADD | BPF_X:
- emit(A64_ADD(is64, dst, dst, src), ctx);
+ emit(A64_ADD(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_SUB | BPF_X:
case BPF_ALU64 | BPF_SUB | BPF_X:
- emit(A64_SUB(is64, dst, dst, src), ctx);
+ emit(A64_SUB(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_AND | BPF_X:
case BPF_ALU64 | BPF_AND | BPF_X:
- emit(A64_AND(is64, dst, dst, src), ctx);
+ emit(A64_AND(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_OR | BPF_X:
case BPF_ALU64 | BPF_OR | BPF_X:
- emit(A64_ORR(is64, dst, dst, src), ctx);
+ emit(A64_ORR(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_XOR | BPF_X:
case BPF_ALU64 | BPF_XOR | BPF_X:
- emit(A64_EOR(is64, dst, dst, src), ctx);
+ emit(A64_EOR(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_MUL | BPF_X:
case BPF_ALU64 | BPF_MUL | BPF_X:
- emit(A64_MUL(is64, dst, dst, src), ctx);
+ emit(A64_MUL(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
@@ -410,30 +411,30 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
case BPF_ALU64 | BPF_MOD | BPF_X:
switch (BPF_OP(code)) {
case BPF_DIV:
- emit(A64_UDIV(is64, dst, dst, src), ctx);
+ emit(A64_UDIV(is64, dstw, dstr, src), ctx);
break;
case BPF_MOD:
- emit(A64_UDIV(is64, tmp, dst, src), ctx);
- emit(A64_MSUB(is64, dst, dst, tmp, src), ctx);
+ emit(A64_UDIV(is64, tmp, dstr, src), ctx);
+ emit(A64_MSUB(is64, dstw, dstr, tmp, src), ctx);
break;
}
break;
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU64 | BPF_LSH | BPF_X:
- emit(A64_LSLV(is64, dst, dst, src), ctx);
+ emit(A64_LSLV(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_RSH | BPF_X:
case BPF_ALU64 | BPF_RSH | BPF_X:
- emit(A64_LSRV(is64, dst, dst, src), ctx);
+ emit(A64_LSRV(is64, dstw, dstr, src), ctx);
break;
case BPF_ALU | BPF_ARSH | BPF_X:
case BPF_ALU64 | BPF_ARSH | BPF_X:
- emit(A64_ASRV(is64, dst, dst, src), ctx);
+ emit(A64_ASRV(is64, dstw, dstr, src), ctx);
break;
/* dst = -dst */
case BPF_ALU | BPF_NEG:
case BPF_ALU64 | BPF_NEG:
- emit(A64_NEG(is64, dst, dst), ctx);
+ emit(A64_NEG(is64, dstw, dstr), ctx);
break;
/* dst = BSWAP##imm(dst) */
case BPF_ALU | BPF_END | BPF_FROM_LE:
@@ -447,16 +448,16 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
#endif
switch (imm) {
case 16:
- emit(A64_REV16(is64, dst, dst), ctx);
+ emit(A64_REV16(is64, dstw, dstr), ctx);
/* zero-extend 16 bits into 64 bits */
- emit(A64_UXTH(is64, dst, dst), ctx);
+ emit(A64_UXTH(is64, dstw, dstr), ctx);
break;
case 32:
- emit(A64_REV32(is64, dst, dst), ctx);
+ emit(A64_REV32(is64, dstw, dstr), ctx);
/* upper 32 bits already cleared */
break;
case 64:
- emit(A64_REV64(dst, dst), ctx);
+ emit(A64_REV64(dstw, dstr), ctx);
break;
}
break;
@@ -464,11 +465,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
switch (imm) {
case 16:
/* zero-extend 16 bits into 64 bits */
- emit(A64_UXTH(is64, dst, dst), ctx);
+ emit(A64_UXTH(is64, dstw, dstr), ctx);
break;
case 32:
/* zero-extend 32 bits into 64 bits */
- emit(A64_UXTW(is64, dst, dst), ctx);
+ emit(A64_UXTW(is64, dstw, dstr), ctx);
break;
case 64:
/* nop */
@@ -478,61 +479,61 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
/* dst = imm */
case BPF_ALU | BPF_MOV | BPF_K:
case BPF_ALU64 | BPF_MOV | BPF_K:
- emit_a64_mov_i(is64, dst, imm, ctx);
+ emit_a64_mov_i(is64, dstw, imm, ctx);
break;
/* dst = dst OP imm */
case BPF_ALU | BPF_ADD | BPF_K:
case BPF_ALU64 | BPF_ADD | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_ADD(is64, dst, dst, tmp), ctx);
+ emit(A64_ADD(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_SUB | BPF_K:
case BPF_ALU64 | BPF_SUB | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_SUB(is64, dst, dst, tmp), ctx);
+ emit(A64_SUB(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_AND | BPF_K:
case BPF_ALU64 | BPF_AND | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_AND(is64, dst, dst, tmp), ctx);
+ emit(A64_AND(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_OR | BPF_K:
case BPF_ALU64 | BPF_OR | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_ORR(is64, dst, dst, tmp), ctx);
+ emit(A64_ORR(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_XOR | BPF_K:
case BPF_ALU64 | BPF_XOR | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_EOR(is64, dst, dst, tmp), ctx);
+ emit(A64_EOR(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_MUL(is64, dst, dst, tmp), ctx);
+ emit(A64_MUL(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_UDIV(is64, dst, dst, tmp), ctx);
+ emit(A64_UDIV(is64, dstw, dstr, tmp), ctx);
break;
case BPF_ALU | BPF_MOD | BPF_K:
case BPF_ALU64 | BPF_MOD | BPF_K:
emit_a64_mov_i(is64, tmp2, imm, ctx);
- emit(A64_UDIV(is64, tmp, dst, tmp2), ctx);
- emit(A64_MSUB(is64, dst, dst, tmp, tmp2), ctx);
+ emit(A64_UDIV(is64, tmp, dstr, tmp2), ctx);
+ emit(A64_MSUB(is64, dstw, dstr, tmp, tmp2), ctx);
break;
case BPF_ALU | BPF_LSH | BPF_K:
case BPF_ALU64 | BPF_LSH | BPF_K:
- emit(A64_LSL(is64, dst, dst, imm), ctx);
+ emit(A64_LSL(is64, dstw, dstr, imm), ctx);
break;
case BPF_ALU | BPF_RSH | BPF_K:
case BPF_ALU64 | BPF_RSH | BPF_K:
- emit(A64_LSR(is64, dst, dst, imm), ctx);
+ emit(A64_LSR(is64, dstw, dstr, imm), ctx);
break;
case BPF_ALU | BPF_ARSH | BPF_K:
case BPF_ALU64 | BPF_ARSH | BPF_K:
- emit(A64_ASR(is64, dst, dst, imm), ctx);
+ emit(A64_ASR(is64, dstw, dstr, imm), ctx);
break;

/* JUMP off */
@@ -562,7 +563,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
case BPF_JMP32 | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_X:
- emit(A64_CMP(is64, dst, src), ctx);
+ emit(A64_CMP(is64, dstr, src), ctx);
emit_cond_jmp:
jmp_offset = bpf2a64_offset(i + off, i, ctx);
check_imm19(jmp_offset);
@@ -605,7 +606,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
case BPF_JMP | BPF_JSET | BPF_X:
case BPF_JMP32 | BPF_JSET | BPF_X:
- emit(A64_TST(is64, dst, src), ctx);
+ emit(A64_TST(is64, dstr, src), ctx);
goto emit_cond_jmp;
/* IF (dst COND imm) JUMP off */
case BPF_JMP | BPF_JEQ | BPF_K:
@@ -629,12 +630,12 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_CMP(is64, dst, tmp), ctx);
+ emit(A64_CMP(is64, dstr, tmp), ctx);
goto emit_cond_jmp;
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP32 | BPF_JSET | BPF_K:
emit_a64_mov_i(is64, tmp, imm, ctx);
- emit(A64_TST(is64, dst, tmp), ctx);
+ emit(A64_TST(is64, dstr, tmp), ctx);
goto emit_cond_jmp;
/* function call */
case BPF_JMP | BPF_CALL:
@@ -676,7 +677,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
u64 imm64;

imm64 = (u64)insn1.imm << 32 | (u32)imm;
- emit_a64_mov_i64(dst, imm64, ctx);
+ emit_a64_mov_i64(dstw, imm64, ctx);

return 1;
}
@@ -689,16 +690,16 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_a64_mov_i(1, tmp, off, ctx);
switch (BPF_SIZE(code)) {
case BPF_W:
- emit(A64_LDR32(dst, src, tmp), ctx);
+ emit(A64_LDR32(dstw, src, tmp), ctx);
break;
case BPF_H:
- emit(A64_LDRH(dst, src, tmp), ctx);
+ emit(A64_LDRH(dstw, src, tmp), ctx);
break;
case BPF_B:
- emit(A64_LDRB(dst, src, tmp), ctx);
+ emit(A64_LDRB(dstw, src, tmp), ctx);
break;
case BPF_DW:
- emit(A64_LDR64(dst, src, tmp), ctx);
+ emit(A64_LDR64(dstw, src, tmp), ctx);
break;
}
break;
@@ -713,16 +714,16 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_a64_mov_i(1, tmp, imm, ctx);
switch (BPF_SIZE(code)) {
case BPF_W:
- emit(A64_STR32(tmp, dst, tmp2), ctx);
+ emit(A64_STR32(tmp, dstr, tmp2), ctx);
break;
case BPF_H:
- emit(A64_STRH(tmp, dst, tmp2), ctx);
+ emit(A64_STRH(tmp, dstr, tmp2), ctx);
break;
case BPF_B:
- emit(A64_STRB(tmp, dst, tmp2), ctx);
+ emit(A64_STRB(tmp, dstr, tmp2), ctx);
break;
case BPF_DW:
- emit(A64_STR64(tmp, dst, tmp2), ctx);
+ emit(A64_STR64(tmp, dstr, tmp2), ctx);
break;
}
break;
@@ -735,16 +736,16 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_a64_mov_i(1, tmp, off, ctx);
switch (BPF_SIZE(code)) {
case BPF_W:
- emit(A64_STR32(src, dst, tmp), ctx);
+ emit(A64_STR32(src, dstr, tmp), ctx);
break;
case BPF_H:
- emit(A64_STRH(src, dst, tmp), ctx);
+ emit(A64_STRH(src, dstr, tmp), ctx);
break;
case BPF_B:
- emit(A64_STRB(src, dst, tmp), ctx);
+ emit(A64_STRB(src, dstr, tmp), ctx);
break;
case BPF_DW:
- emit(A64_STR64(src, dst, tmp), ctx);
+ emit(A64_STR64(src, dstr, tmp), ctx);
break;
}
break;
@@ -754,10 +755,10 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
/* STX XADD: lock *(u64 *)(dst + off) += src */
case BPF_STX | BPF_XADD | BPF_DW:
if (!off) {
- reg = dst;
+ reg = dstr;
} else {
emit_a64_mov_i(1, tmp, off, ctx);
- emit(A64_ADD(1, tmp, tmp, dst), ctx);
+ emit(A64_ADD(1, tmp, tmp, dstr), ctx);
reg = tmp;
}
if (cpus_have_cap(ARM64_HAS_LSE_ATOMICS)) {
--
2.25.0.341.g760bfbb309-goog

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