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Message-Id: <20180503230824.3462-8-daniel@iogearbox.net>
Date: Fri, 4 May 2018 01:08:18 +0200
From: Daniel Borkmann <daniel@...earbox.net>
To: ast@...nel.org
Cc: netdev@...r.kernel.org, Daniel Borkmann <daniel@...earbox.net>
Subject: [PATCH bpf-next v2 07/13] bpf, sparc64: remove ld_abs/ld_ind
Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from sparc64 JIT.
Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Alexei Starovoitov <ast@...nel.org>
Acked-by: David S. Miller <davem@...emloft.net>
---
arch/sparc/net/Makefile | 5 +-
arch/sparc/net/bpf_jit_64.h | 29 -------
arch/sparc/net/bpf_jit_asm_64.S | 162 ---------------------------------------
arch/sparc/net/bpf_jit_comp_64.c | 79 +------------------
4 files changed, 6 insertions(+), 269 deletions(-)
delete mode 100644 arch/sparc/net/bpf_jit_asm_64.S
diff --git a/arch/sparc/net/Makefile b/arch/sparc/net/Makefile
index 76fa8e9..d32aac3 100644
--- a/arch/sparc/net/Makefile
+++ b/arch/sparc/net/Makefile
@@ -1,4 +1,7 @@
#
# Arch-specific network modules
#
-obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_$(BITS).o bpf_jit_comp_$(BITS).o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp_$(BITS).o
+ifeq ($(BITS),32)
+obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_32.o
+endif
diff --git a/arch/sparc/net/bpf_jit_64.h b/arch/sparc/net/bpf_jit_64.h
index 428f7fd..fbc836f 100644
--- a/arch/sparc/net/bpf_jit_64.h
+++ b/arch/sparc/net/bpf_jit_64.h
@@ -33,35 +33,6 @@
#define I5 0x1d
#define FP 0x1e
#define I7 0x1f
-
-#define r_SKB L0
-#define r_HEADLEN L4
-#define r_SKB_DATA L5
-#define r_TMP G1
-#define r_TMP2 G3
-
-/* assembly code in arch/sparc/net/bpf_jit_asm_64.S */
-extern u32 bpf_jit_load_word[];
-extern u32 bpf_jit_load_half[];
-extern u32 bpf_jit_load_byte[];
-extern u32 bpf_jit_load_byte_msh[];
-extern u32 bpf_jit_load_word_positive_offset[];
-extern u32 bpf_jit_load_half_positive_offset[];
-extern u32 bpf_jit_load_byte_positive_offset[];
-extern u32 bpf_jit_load_byte_msh_positive_offset[];
-extern u32 bpf_jit_load_word_negative_offset[];
-extern u32 bpf_jit_load_half_negative_offset[];
-extern u32 bpf_jit_load_byte_negative_offset[];
-extern u32 bpf_jit_load_byte_msh_negative_offset[];
-
-#else
-#define r_RESULT %o0
-#define r_SKB %o0
-#define r_OFF %o1
-#define r_HEADLEN %l4
-#define r_SKB_DATA %l5
-#define r_TMP %g1
-#define r_TMP2 %g3
#endif
#endif /* _BPF_JIT_H */
diff --git a/arch/sparc/net/bpf_jit_asm_64.S b/arch/sparc/net/bpf_jit_asm_64.S
deleted file mode 100644
index 7177867..0000000
--- a/arch/sparc/net/bpf_jit_asm_64.S
+++ /dev/null
@@ -1,162 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/ptrace.h>
-
-#include "bpf_jit_64.h"
-
-#define SAVE_SZ 176
-#define SCRATCH_OFF STACK_BIAS + 128
-#define BE_PTR(label) be,pn %xcc, label
-#define SIGN_EXTEND(reg) sra reg, 0, reg
-
-#define SKF_MAX_NEG_OFF (-0x200000) /* SKF_LL_OFF from filter.h */
-
- .text
- .globl bpf_jit_load_word
-bpf_jit_load_word:
- cmp r_OFF, 0
- bl bpf_slow_path_word_neg
- nop
- .globl bpf_jit_load_word_positive_offset
-bpf_jit_load_word_positive_offset:
- sub r_HEADLEN, r_OFF, r_TMP
- cmp r_TMP, 3
- ble bpf_slow_path_word
- add r_SKB_DATA, r_OFF, r_TMP
- andcc r_TMP, 3, %g0
- bne load_word_unaligned
- nop
- retl
- ld [r_TMP], r_RESULT
-load_word_unaligned:
- ldub [r_TMP + 0x0], r_OFF
- ldub [r_TMP + 0x1], r_TMP2
- sll r_OFF, 8, r_OFF
- or r_OFF, r_TMP2, r_OFF
- ldub [r_TMP + 0x2], r_TMP2
- sll r_OFF, 8, r_OFF
- or r_OFF, r_TMP2, r_OFF
- ldub [r_TMP + 0x3], r_TMP2
- sll r_OFF, 8, r_OFF
- retl
- or r_OFF, r_TMP2, r_RESULT
-
- .globl bpf_jit_load_half
-bpf_jit_load_half:
- cmp r_OFF, 0
- bl bpf_slow_path_half_neg
- nop
- .globl bpf_jit_load_half_positive_offset
-bpf_jit_load_half_positive_offset:
- sub r_HEADLEN, r_OFF, r_TMP
- cmp r_TMP, 1
- ble bpf_slow_path_half
- add r_SKB_DATA, r_OFF, r_TMP
- andcc r_TMP, 1, %g0
- bne load_half_unaligned
- nop
- retl
- lduh [r_TMP], r_RESULT
-load_half_unaligned:
- ldub [r_TMP + 0x0], r_OFF
- ldub [r_TMP + 0x1], r_TMP2
- sll r_OFF, 8, r_OFF
- retl
- or r_OFF, r_TMP2, r_RESULT
-
- .globl bpf_jit_load_byte
-bpf_jit_load_byte:
- cmp r_OFF, 0
- bl bpf_slow_path_byte_neg
- nop
- .globl bpf_jit_load_byte_positive_offset
-bpf_jit_load_byte_positive_offset:
- cmp r_OFF, r_HEADLEN
- bge bpf_slow_path_byte
- nop
- retl
- ldub [r_SKB_DATA + r_OFF], r_RESULT
-
-#define bpf_slow_path_common(LEN) \
- save %sp, -SAVE_SZ, %sp; \
- mov %i0, %o0; \
- mov %i1, %o1; \
- add %fp, SCRATCH_OFF, %o2; \
- call skb_copy_bits; \
- mov (LEN), %o3; \
- cmp %o0, 0; \
- restore;
-
-bpf_slow_path_word:
- bpf_slow_path_common(4)
- bl bpf_error
- ld [%sp + SCRATCH_OFF], r_RESULT
- retl
- nop
-bpf_slow_path_half:
- bpf_slow_path_common(2)
- bl bpf_error
- lduh [%sp + SCRATCH_OFF], r_RESULT
- retl
- nop
-bpf_slow_path_byte:
- bpf_slow_path_common(1)
- bl bpf_error
- ldub [%sp + SCRATCH_OFF], r_RESULT
- retl
- nop
-
-#define bpf_negative_common(LEN) \
- save %sp, -SAVE_SZ, %sp; \
- mov %i0, %o0; \
- mov %i1, %o1; \
- SIGN_EXTEND(%o1); \
- call bpf_internal_load_pointer_neg_helper; \
- mov (LEN), %o2; \
- mov %o0, r_TMP; \
- cmp %o0, 0; \
- BE_PTR(bpf_error); \
- restore;
-
-bpf_slow_path_word_neg:
- sethi %hi(SKF_MAX_NEG_OFF), r_TMP
- cmp r_OFF, r_TMP
- bl bpf_error
- nop
- .globl bpf_jit_load_word_negative_offset
-bpf_jit_load_word_negative_offset:
- bpf_negative_common(4)
- andcc r_TMP, 3, %g0
- bne load_word_unaligned
- nop
- retl
- ld [r_TMP], r_RESULT
-
-bpf_slow_path_half_neg:
- sethi %hi(SKF_MAX_NEG_OFF), r_TMP
- cmp r_OFF, r_TMP
- bl bpf_error
- nop
- .globl bpf_jit_load_half_negative_offset
-bpf_jit_load_half_negative_offset:
- bpf_negative_common(2)
- andcc r_TMP, 1, %g0
- bne load_half_unaligned
- nop
- retl
- lduh [r_TMP], r_RESULT
-
-bpf_slow_path_byte_neg:
- sethi %hi(SKF_MAX_NEG_OFF), r_TMP
- cmp r_OFF, r_TMP
- bl bpf_error
- nop
- .globl bpf_jit_load_byte_negative_offset
-bpf_jit_load_byte_negative_offset:
- bpf_negative_common(1)
- retl
- ldub [r_TMP], r_RESULT
-
-bpf_error:
- /* Make the JIT program itself return zero. */
- ret
- restore %g0, %g0, %o0
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index 48a2586..9f5918e 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c
@@ -48,10 +48,6 @@ static void bpf_flush_icache(void *start_, void *end_)
}
}
-#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 S5(X) ((X) & 0x1f)
#define IMMED 0x00002000
@@ -198,7 +194,6 @@ struct jit_ctx {
bool tmp_1_used;
bool tmp_2_used;
bool tmp_3_used;
- bool saw_ld_abs_ind;
bool saw_frame_pointer;
bool saw_call;
bool saw_tail_call;
@@ -207,9 +202,7 @@ struct jit_ctx {
#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
-#define SKB_HLEN_REG (MAX_BPF_JIT_REG + 2)
-#define SKB_DATA_REG (MAX_BPF_JIT_REG + 3)
-#define TMP_REG_3 (MAX_BPF_JIT_REG + 4)
+#define TMP_REG_3 (MAX_BPF_JIT_REG + 2)
/* Map BPF registers to SPARC registers */
static const int bpf2sparc[] = {
@@ -238,9 +231,6 @@ static const int bpf2sparc[] = {
[TMP_REG_1] = G1,
[TMP_REG_2] = G2,
[TMP_REG_3] = G3,
-
- [SKB_HLEN_REG] = L4,
- [SKB_DATA_REG] = L5,
};
static void emit(const u32 insn, struct jit_ctx *ctx)
@@ -800,25 +790,6 @@ static int emit_compare_and_branch(const u8 code, const u8 dst, u8 src,
return 0;
}
-static void load_skb_regs(struct jit_ctx *ctx, u8 r_skb)
-{
- const u8 r_headlen = bpf2sparc[SKB_HLEN_REG];
- const u8 r_data = bpf2sparc[SKB_DATA_REG];
- const u8 r_tmp = bpf2sparc[TMP_REG_1];
- unsigned int off;
-
- off = offsetof(struct sk_buff, len);
- emit(LD32I | RS1(r_skb) | S13(off) | RD(r_headlen), ctx);
-
- off = offsetof(struct sk_buff, data_len);
- emit(LD32I | RS1(r_skb) | S13(off) | RD(r_tmp), ctx);
-
- emit(SUB | RS1(r_headlen) | RS2(r_tmp) | RD(r_headlen), ctx);
-
- off = offsetof(struct sk_buff, data);
- emit(LDPTRI | RS1(r_skb) | S13(off) | RD(r_data), ctx);
-}
-
/* Just skip the save instruction and the ctx register move. */
#define BPF_TAILCALL_PROLOGUE_SKIP 16
#define BPF_TAILCALL_CNT_SP_OFF (STACK_BIAS + 128)
@@ -857,9 +828,6 @@ static void build_prologue(struct jit_ctx *ctx)
emit_reg_move(I0, O0, ctx);
/* If you add anything here, adjust BPF_TAILCALL_PROLOGUE_SKIP above. */
-
- if (ctx->saw_ld_abs_ind)
- load_skb_regs(ctx, bpf2sparc[BPF_REG_1]);
}
static void build_epilogue(struct jit_ctx *ctx)
@@ -1225,16 +1193,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
u8 *func = ((u8 *)__bpf_call_base) + imm;
ctx->saw_call = true;
- if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
- emit_reg_move(bpf2sparc[BPF_REG_1], L7, ctx);
emit_call((u32 *)func, ctx);
emit_nop(ctx);
emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
-
- if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
- load_skb_regs(ctx, L7);
break;
}
@@ -1412,43 +1375,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
emit_nop(ctx);
break;
}
-#define CHOOSE_LOAD_FUNC(K, func) \
- ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
-
- /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
- case BPF_LD | BPF_ABS | BPF_W:
- func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_word);
- goto common_load;
- case BPF_LD | BPF_ABS | BPF_H:
- func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_half);
- goto common_load;
- case BPF_LD | BPF_ABS | BPF_B:
- func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_byte);
- goto common_load;
- /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
- case BPF_LD | BPF_IND | BPF_W:
- func = bpf_jit_load_word;
- goto common_load;
- case BPF_LD | BPF_IND | BPF_H:
- func = bpf_jit_load_half;
- goto common_load;
-
- case BPF_LD | BPF_IND | BPF_B:
- func = bpf_jit_load_byte;
- common_load:
- ctx->saw_ld_abs_ind = true;
-
- emit_reg_move(bpf2sparc[BPF_REG_6], O0, ctx);
- emit_loadimm(imm, O1, ctx);
-
- if (BPF_MODE(code) == BPF_IND)
- emit_alu(ADD, src, O1, ctx);
-
- emit_call(func, ctx);
- emit_alu_K(SRA, O1, 0, ctx);
-
- emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
- break;
default:
pr_err_once("unknown opcode %02x\n", code);
@@ -1583,12 +1509,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
build_epilogue(&ctx);
if (bpf_jit_enable > 1)
- pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c%c]\n", pass,
+ pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c]\n", pass,
image_size - (ctx.idx * 4),
ctx.tmp_1_used ? '1' : ' ',
ctx.tmp_2_used ? '2' : ' ',
ctx.tmp_3_used ? '3' : ' ',
- ctx.saw_ld_abs_ind ? 'L' : ' ',
ctx.saw_frame_pointer ? 'F' : ' ',
ctx.saw_call ? 'C' : ' ',
ctx.saw_tail_call ? 'T' : ' ');
--
2.9.5
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