From a8ef95a034233190b1dd73ff03472ff0f7f4fbdf Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 11 Jul 2018 10:31:36 +0100 Subject: [PATCH] ARM: net: bpf: provide load/store ops with negative immediates Provide a set of load/store opcode generators that work with negative immediates as well as positive ones. Signed-off-by: Russell King Signed-off-by: Daniel Borkmann --- arch/arm/net/bpf_jit_32.c | 28 ++++++++++++++++++++++++++++ arch/arm/net/bpf_jit_32.h | 35 +++++++++++++---------------------- 2 files changed, 41 insertions(+), 22 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index f2e6ffe..c81da1a 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -239,6 +239,34 @@ static int16_t imm8m(u32 x) return -1; } +static u32 arm_bpf_ldst_imm12(u32 op, u8 rt, u8 rn, s16 imm12) +{ + op |= rt << 12 | rn << 16; + if (imm12 >= 0) + op |= ARM_INST_LDST__U; + else + imm12 = -imm12; + return op | (imm12 & 0xfff); +} + +static u32 arm_bpf_ldst_imm8(u32 op, u8 rt, u8 rn, s16 imm8) +{ + op |= rt << 12 | rn << 16; + if (imm8 >= 0) + op |= ARM_INST_LDST__U; + else + imm8 = -imm8; + return op | (imm8 & 0xf0) << 4 | (imm8 & 0x0f); +} + +#define ARM_LDR_I(rt, rn, off) arm_bpf_ldst_imm12(ARM_INST_LDR_I, rt, rn, off) +#define ARM_LDRB_I(rt, rn, off) arm_bpf_ldst_imm12(ARM_INST_LDRB_I, rt, rn, off) +#define ARM_LDRH_I(rt, rn, off) arm_bpf_ldst_imm8(ARM_INST_LDRH_I, rt, rn, off) + +#define ARM_STR_I(rt, rn, off) arm_bpf_ldst_imm12(ARM_INST_STR_I, rt, rn, off) +#define ARM_STRB_I(rt, rn, off) arm_bpf_ldst_imm12(ARM_INST_STRB_I, rt, rn, off) +#define ARM_STRH_I(rt, rn, off) arm_bpf_ldst_imm8(ARM_INST_STRH_I, rt, rn, off) + /* * Initializes the JIT space with undefined instructions. */ diff --git a/arch/arm/net/bpf_jit_32.h b/arch/arm/net/bpf_jit_32.h index d5cf5f6..c55bc39 100644 --- a/arch/arm/net/bpf_jit_32.h +++ b/arch/arm/net/bpf_jit_32.h @@ -77,11 +77,12 @@ #define ARM_INST_EOR_R 0x00200000 #define ARM_INST_EOR_I 0x02200000 -#define ARM_INST_LDRB_I 0x05d00000 +#define ARM_INST_LDST__U 0x00800000 +#define ARM_INST_LDRB_I 0x05500000 #define ARM_INST_LDRB_R 0x07d00000 -#define ARM_INST_LDRH_I 0x01d000b0 +#define ARM_INST_LDRH_I 0x015000b0 #define ARM_INST_LDRH_R 0x019000b0 -#define ARM_INST_LDR_I 0x05900000 +#define ARM_INST_LDR_I 0x05100000 #define ARM_INST_LDR_R 0x07900000 #define ARM_INST_LDM 0x08900000 @@ -124,9 +125,9 @@ #define ARM_INST_SBC_R 0x00c00000 #define ARM_INST_SBCS_R 0x00d00000 -#define ARM_INST_STR_I 0x05800000 -#define ARM_INST_STRB_I 0x05c00000 -#define ARM_INST_STRH_I 0x01c000b0 +#define ARM_INST_STR_I 0x05000000 +#define ARM_INST_STRB_I 0x05400000 +#define ARM_INST_STRH_I 0x014000b0 #define ARM_INST_TST_R 0x01100000 #define ARM_INST_TST_I 0x03100000 @@ -183,17 +184,14 @@ #define ARM_EOR_R(rd, rn, rm) _AL3_R(ARM_INST_EOR, rd, rn, rm) #define ARM_EOR_I(rd, rn, imm) _AL3_I(ARM_INST_EOR, rd, rn, imm) -#define ARM_LDR_I(rt, rn, off) (ARM_INST_LDR_I | (rt) << 12 | (rn) << 16 \ - | ((off) & 0xfff)) -#define ARM_LDR_R(rt, rn, rm) (ARM_INST_LDR_R | (rt) << 12 | (rn) << 16 \ +#define ARM_LDR_R(rt, rn, rm) (ARM_INST_LDR_R | ARM_INST_LDST__U \ + | (rt) << 12 | (rn) << 16 \ | (rm)) -#define ARM_LDRB_I(rt, rn, off) (ARM_INST_LDRB_I | (rt) << 12 | (rn) << 16 \ - | (off)) -#define ARM_LDRB_R(rt, rn, rm) (ARM_INST_LDRB_R | (rt) << 12 | (rn) << 16 \ +#define ARM_LDRB_R(rt, rn, rm) (ARM_INST_LDRB_R | ARM_INST_LDST__U \ + | (rt) << 12 | (rn) << 16 \ | (rm)) -#define ARM_LDRH_I(rt, rn, off) (ARM_INST_LDRH_I | (rt) << 12 | (rn) << 16 \ - | (((off) & 0xf0) << 4) | ((off) & 0xf)) -#define ARM_LDRH_R(rt, rn, rm) (ARM_INST_LDRH_R | (rt) << 12 | (rn) << 16 \ +#define ARM_LDRH_R(rt, rn, rm) (ARM_INST_LDRH_R | ARM_INST_LDST__U \ + | (rt) << 12 | (rn) << 16 \ | (rm)) #define ARM_LDM(rn, regs) (ARM_INST_LDM | (rn) << 16 | (regs)) @@ -254,13 +252,6 @@ #define ARM_SUBS_I(rd, rn, imm) _AL3_I(ARM_INST_SUBS, rd, rn, imm) #define ARM_SBC_I(rd, rn, imm) _AL3_I(ARM_INST_SBC, rd, rn, imm) -#define ARM_STR_I(rt, rn, off) (ARM_INST_STR_I | (rt) << 12 | (rn) << 16 \ - | ((off) & 0xfff)) -#define ARM_STRH_I(rt, rn, off) (ARM_INST_STRH_I | (rt) << 12 | (rn) << 16 \ - | (((off) & 0xf0) << 4) | ((off) & 0xf)) -#define ARM_STRB_I(rt, rn, off) (ARM_INST_STRB_I | (rt) << 12 | (rn) << 16 \ - | (((off) & 0xf0) << 4) | ((off) & 0xf)) - #define ARM_TST_R(rn, rm) _AL3_R(ARM_INST_TST, 0, rn, rm) #define ARM_TST_I(rn, imm) _AL3_I(ARM_INST_TST, 0, rn, imm) -- 2.7.4