diff options
Diffstat (limited to 'arch/arm/net/bpf_jit_32.c')
| -rw-r--r-- | arch/arm/net/bpf_jit_32.c | 61 |
1 files changed, 37 insertions, 24 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index b8efb8cd1..93d0b6d0b 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -125,7 +125,7 @@ static u64 jit_get_skb_w(struct sk_buff *skb, int offset) } /* - * Wrapper that handles both OABI and EABI and assures Thumb2 interworking + * Wrappers which handle both OABI and EABI and assures Thumb2 interworking * (where the assembly routines like __aeabi_uidiv could cause problems). */ static u32 jit_udiv(u32 dividend, u32 divisor) @@ -133,6 +133,11 @@ static u32 jit_udiv(u32 dividend, u32 divisor) return dividend / divisor; } +static u32 jit_mod(u32 dividend, u32 divisor) +{ + return dividend % divisor; +} + static inline void _emit(int cond, u32 inst, struct jit_ctx *ctx) { inst |= (cond << 28); @@ -182,19 +187,6 @@ static inline int mem_words_used(struct jit_ctx *ctx) return fls(ctx->seen & SEEN_MEM); } -static inline bool is_load_to_a(u16 inst) -{ - switch (inst) { - case BPF_LD | BPF_W | BPF_LEN: - case BPF_LD | BPF_W | BPF_ABS: - case BPF_LD | BPF_H | BPF_ABS: - case BPF_LD | BPF_B | BPF_ABS: - return true; - default: - return false; - } -} - static void jit_fill_hole(void *area, unsigned int size) { u32 *ptr; @@ -206,7 +198,6 @@ static void jit_fill_hole(void *area, unsigned int size) static void build_prologue(struct jit_ctx *ctx) { u16 reg_set = saved_regs(ctx); - u16 first_inst = ctx->skf->insns[0].code; u16 off; #ifdef CONFIG_FRAME_POINTER @@ -236,7 +227,7 @@ static void build_prologue(struct jit_ctx *ctx) emit(ARM_MOV_I(r_X, 0), ctx); /* do not leak kernel data to userspace */ - if ((first_inst != (BPF_RET | BPF_K)) && !(is_load_to_a(first_inst))) + if (bpf_needs_clear_a(&ctx->skf->insns[0])) emit(ARM_MOV_I(r_A, 0), ctx); /* stack space for the BPF_MEM words */ @@ -471,11 +462,17 @@ static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx) #endif } -static inline void emit_udiv(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx) +static inline void emit_udivmod(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx, + int bpf_op) { #if __LINUX_ARM_ARCH__ == 7 if (elf_hwcap & HWCAP_IDIVA) { - emit(ARM_UDIV(rd, rm, rn), ctx); + if (bpf_op == BPF_DIV) + emit(ARM_UDIV(rd, rm, rn), ctx); + else { + emit(ARM_UDIV(ARM_R3, rm, rn), ctx); + emit(ARM_MLS(rd, rn, ARM_R3, rm), ctx); + } return; } #endif @@ -496,7 +493,8 @@ static inline void emit_udiv(u8 rd, u8 rm, u8 rn, struct jit_ctx *ctx) emit(ARM_MOV_R(ARM_R0, rm), ctx); ctx->seen |= SEEN_CALL; - emit_mov_i(ARM_R3, (u32)jit_udiv, ctx); + emit_mov_i(ARM_R3, bpf_op == BPF_DIV ? (u32)jit_udiv : (u32)jit_mod, + ctx); emit_blx_r(ARM_R3, ctx); if (rd != ARM_R0) @@ -698,13 +696,27 @@ load_ind: if (k == 1) break; emit_mov_i(r_scratch, k, ctx); - emit_udiv(r_A, r_A, r_scratch, ctx); + emit_udivmod(r_A, r_A, r_scratch, ctx, BPF_DIV); break; case BPF_ALU | BPF_DIV | BPF_X: update_on_xread(ctx); emit(ARM_CMP_I(r_X, 0), ctx); emit_err_ret(ARM_COND_EQ, ctx); - emit_udiv(r_A, r_A, r_X, ctx); + emit_udivmod(r_A, r_A, r_X, ctx, BPF_DIV); + break; + case BPF_ALU | BPF_MOD | BPF_K: + if (k == 1) { + emit_mov_i(r_A, 0, ctx); + break; + } + emit_mov_i(r_scratch, k, ctx); + emit_udivmod(r_A, r_A, r_scratch, ctx, BPF_MOD); + break; + case BPF_ALU | BPF_MOD | BPF_X: + update_on_xread(ctx); + emit(ARM_CMP_I(r_X, 0), ctx); + emit_err_ret(ARM_COND_EQ, ctx); + emit_udivmod(r_A, r_A, r_X, ctx, BPF_MOD); break; case BPF_ALU | BPF_OR | BPF_K: /* A |= K */ @@ -744,7 +756,8 @@ load_ind: case BPF_ALU | BPF_RSH | BPF_K: if (unlikely(k > 31)) return -1; - emit(ARM_LSR_I(r_A, r_A, k), ctx); + if (k) + emit(ARM_LSR_I(r_A, r_A, k), ctx); break; case BPF_ALU | BPF_RSH | BPF_X: update_on_xread(ctx); @@ -1035,7 +1048,7 @@ void bpf_jit_compile(struct bpf_prog *fp) } build_epilogue(&ctx); - flush_icache_range((u32)ctx.target, (u32)(ctx.target + ctx.idx)); + flush_icache_range((u32)header, (u32)(ctx.target + ctx.idx)); #if __LINUX_ARM_ARCH__ < 7 if (ctx.imm_count) @@ -1048,7 +1061,7 @@ void bpf_jit_compile(struct bpf_prog *fp) set_memory_ro((unsigned long)header, header->pages); fp->bpf_func = (void *)ctx.target; - fp->jited = true; + fp->jited = 1; out: kfree(ctx.offsets); return; |