From 0d2d0cedc0814edaa2b6cb290c78ec333b3eed71 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 4 May 2018 01:08:19 +0200 Subject: [PATCH] bpf, arm32: 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 arm32 JIT. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: Alexei Starovoitov --- arch/arm/net/bpf_jit_32.c | 77 --------------------------------------- 1 file changed, 77 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index b5030e1a41d8..82689b999257 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -1452,83 +1452,6 @@ exit: emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx); emit_ldx_r(dst, rn, dstk, off, ctx, BPF_SIZE(code)); break; - /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */ - case BPF_LD | BPF_ABS | BPF_W: - case BPF_LD | BPF_ABS | BPF_H: - case BPF_LD | BPF_ABS | BPF_B: - /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */ - case BPF_LD | BPF_IND | BPF_W: - case BPF_LD | BPF_IND | BPF_H: - case BPF_LD | BPF_IND | BPF_B: - { - const u8 r4 = bpf2a32[BPF_REG_6][1]; /* r4 = ptr to sk_buff */ - const u8 r0 = bpf2a32[BPF_REG_0][1]; /*r0: struct sk_buff *skb*/ - /* rtn value */ - const u8 r1 = bpf2a32[BPF_REG_0][0]; /* r1: int k */ - const u8 r2 = bpf2a32[BPF_REG_1][1]; /* r2: unsigned int size */ - const u8 r3 = bpf2a32[BPF_REG_1][0]; /* r3: void *buffer */ - const u8 r6 = bpf2a32[TMP_REG_1][1]; /* r6: void *(*func)(..) */ - int size; - - /* Setting up first argument */ - emit(ARM_MOV_R(r0, r4), ctx); - - /* Setting up second argument */ - emit_a32_mov_i(r1, imm, false, ctx); - if (BPF_MODE(code) == BPF_IND) - emit_a32_alu_r(r1, src_lo, false, sstk, ctx, - false, false, BPF_ADD); - - /* Setting up third argument */ - switch (BPF_SIZE(code)) { - case BPF_W: - size = 4; - break; - case BPF_H: - size = 2; - break; - case BPF_B: - size = 1; - break; - default: - return -EINVAL; - } - emit_a32_mov_i(r2, size, false, ctx); - - /* Setting up fourth argument */ - emit(ARM_ADD_I(r3, ARM_SP, imm8m(SKB_BUFFER)), ctx); - - /* Setting up function pointer to call */ - emit_a32_mov_i(r6, (unsigned int)bpf_load_pointer, false, ctx); - emit_blx_r(r6, ctx); - - emit(ARM_EOR_R(r1, r1, r1), ctx); - /* Check if return address is NULL or not. - * if NULL then jump to epilogue - * else continue to load the value from retn address - */ - emit(ARM_CMP_I(r0, 0), ctx); - jmp_offset = epilogue_offset(ctx); - check_imm24(jmp_offset); - _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx); - - /* Load value from the address */ - switch (BPF_SIZE(code)) { - case BPF_W: - emit(ARM_LDR_I(r0, r0, 0), ctx); - emit_rev32(r0, r0, ctx); - break; - case BPF_H: - emit(ARM_LDRH_I(r0, r0, 0), ctx); - emit_rev16(r0, r0, ctx); - break; - case BPF_B: - emit(ARM_LDRB_I(r0, r0, 0), ctx); - /* No need to reverse */ - break; - } - break; - } /* ST: *(size *)(dst + off) = imm */ case BPF_ST | BPF_MEM | BPF_W: case BPF_ST | BPF_MEM | BPF_H: -- 2.30.2