diff options
Diffstat (limited to 'arch/arm64/net')
| -rw-r--r-- | arch/arm64/net/bpf_jit.h | 8 | ||||
| -rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 84 |
2 files changed, 80 insertions, 12 deletions
diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h index 2134f7e6c288..de0a81a539a0 100644 --- a/arch/arm64/net/bpf_jit.h +++ b/arch/arm64/net/bpf_jit.h @@ -144,8 +144,12 @@ /* Data-processing (2 source) */ /* Rd = Rn OP Rm */ -#define A64_UDIV(sf, Rd, Rn, Rm) aarch64_insn_gen_data2(Rd, Rn, Rm, \ - A64_VARIANT(sf), AARCH64_INSN_DATA2_UDIV) +#define A64_DATA2(sf, Rd, Rn, Rm, type) aarch64_insn_gen_data2(Rd, Rn, Rm, \ + A64_VARIANT(sf), AARCH64_INSN_DATA2_##type) +#define A64_UDIV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, UDIV) +#define A64_LSLV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSLV) +#define A64_LSRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, LSRV) +#define A64_ASRV(sf, Rd, Rn, Rm) A64_DATA2(sf, Rd, Rn, Rm, ASRV) /* Data-processing (3 source) */ /* Rd = Ra + Rn * Rm */ diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 7ae33545535b..41f1e3e2ea24 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -19,12 +19,13 @@ #define pr_fmt(fmt) "bpf_jit: " fmt #include <linux/filter.h> -#include <linux/moduleloader.h> #include <linux/printk.h> #include <linux/skbuff.h> #include <linux/slab.h> + #include <asm/byteorder.h> #include <asm/cacheflush.h> +#include <asm/debug-monitors.h> #include "bpf_jit.h" @@ -119,6 +120,14 @@ static inline int bpf2a64_offset(int bpf_to, int bpf_from, return to - from; } +static void jit_fill_hole(void *area, unsigned int size) +{ + u32 *ptr; + /* We are guaranteed to have aligned memory. */ + for (ptr = area; size >= sizeof(u32); size -= sizeof(u32)) + *ptr++ = cpu_to_le32(AARCH64_BREAK_FAULT); +} + static inline int epilogue_offset(const struct jit_ctx *ctx) { int to = ctx->offset[ctx->prog->len - 1]; @@ -196,6 +205,12 @@ static void build_epilogue(struct jit_ctx *ctx) emit(A64_RET(A64_LR), ctx); } +/* JITs an eBPF instruction. + * Returns: + * 0 - successfully JITed an 8-byte eBPF instruction. + * >0 - successfully JITed a 16-byte eBPF instruction. + * <0 - failed to JIT. + */ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) { const u8 code = insn->code; @@ -252,6 +267,18 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) emit(A64_MUL(is64, tmp, tmp, src), ctx); emit(A64_SUB(is64, dst, dst, tmp), ctx); break; + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU64 | BPF_LSH | BPF_X: + emit(A64_LSLV(is64, dst, dst, 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); + break; + case BPF_ALU | BPF_ARSH | BPF_X: + case BPF_ALU64 | BPF_ARSH | BPF_X: + emit(A64_ASRV(is64, dst, dst, src), ctx); + break; /* dst = -dst */ case BPF_ALU | BPF_NEG: case BPF_ALU64 | BPF_NEG: @@ -443,6 +470,27 @@ emit_cond_jmp: emit(A64_B(jmp_offset), ctx); break; + /* dst = imm64 */ + case BPF_LD | BPF_IMM | BPF_DW: + { + const struct bpf_insn insn1 = insn[1]; + u64 imm64; + + if (insn1.code != 0 || insn1.src_reg != 0 || + insn1.dst_reg != 0 || insn1.off != 0) { + /* Note: verifier in BPF core must catch invalid + * instructions. + */ + pr_err_once("Invalid BPF_LD_IMM64 instruction\n"); + return -EINVAL; + } + + imm64 = (u64)insn1.imm << 32 | imm; + emit_a64_mov_i64(dst, imm64, ctx); + + return 1; + } + /* LDX: dst = *(size *)(src + off) */ case BPF_LDX | BPF_MEM | BPF_W: case BPF_LDX | BPF_MEM | BPF_H: @@ -594,6 +642,10 @@ static int build_body(struct jit_ctx *ctx) ctx->offset[i] = ctx->idx; ret = build_insn(insn, ctx); + if (ret > 0) { + i++; + continue; + } if (ret) return ret; } @@ -613,8 +665,10 @@ void bpf_jit_compile(struct bpf_prog *prog) void bpf_int_jit_compile(struct bpf_prog *prog) { + struct bpf_binary_header *header; struct jit_ctx ctx; int image_size; + u8 *image_ptr; if (!bpf_jit_enable) return; @@ -636,23 +690,25 @@ void bpf_int_jit_compile(struct bpf_prog *prog) goto out; build_prologue(&ctx); - build_epilogue(&ctx); /* Now we know the actual image size. */ image_size = sizeof(u32) * ctx.idx; - ctx.image = module_alloc(image_size); - if (unlikely(ctx.image == NULL)) + header = bpf_jit_binary_alloc(image_size, &image_ptr, + sizeof(u32), jit_fill_hole); + if (header == NULL) goto out; /* 2. Now, the actual pass. */ + ctx.image = (u32 *)image_ptr; ctx.idx = 0; + build_prologue(&ctx); ctx.body_offset = ctx.idx; if (build_body(&ctx)) { - module_free(NULL, ctx.image); + bpf_jit_binary_free(header); goto out; } @@ -663,17 +719,25 @@ void bpf_int_jit_compile(struct bpf_prog *prog) bpf_jit_dump(prog->len, image_size, 2, ctx.image); bpf_flush_icache(ctx.image, ctx.image + ctx.idx); - prog->bpf_func = (void *)ctx.image; - prog->jited = 1; + set_memory_ro((unsigned long)header, header->pages); + prog->bpf_func = (void *)ctx.image; + prog->jited = true; out: kfree(ctx.offset); } void bpf_jit_free(struct bpf_prog *prog) { - if (prog->jited) - module_free(NULL, prog->bpf_func); + unsigned long addr = (unsigned long)prog->bpf_func & PAGE_MASK; + struct bpf_binary_header *header = (void *)addr; + + if (!prog->jited) + goto free_filter; + + set_memory_rw(addr, header->pages); + bpf_jit_binary_free(header); - kfree(prog); +free_filter: + bpf_prog_unlock_free(prog); } |