diff options
Diffstat (limited to 'arch/powerpc/net')
-rw-r--r-- | arch/powerpc/net/bpf_jit.h | 17 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp.c | 97 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp32.c | 114 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 105 |
4 files changed, 272 insertions, 61 deletions
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 7e9b978b768e..b20a2a83a6e7 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -31,7 +31,7 @@ pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ return -ERANGE; \ } \ - EMIT(PPC_INST_BRANCH | (offset & 0x03fffffc)); \ + EMIT(PPC_RAW_BRANCH(offset)); \ } while (0) /* blr; (unconditional 'branch' with link) to absolute address */ @@ -125,8 +125,7 @@ #define COND_LE (CR0_GT | COND_CMP_FALSE) #define SEEN_FUNC 0x20000000 /* might call external helpers */ -#define SEEN_STACK 0x40000000 /* uses BPF stack */ -#define SEEN_TAILCALL 0x80000000 /* uses tail calls */ +#define SEEN_TAILCALL 0x40000000 /* uses tail calls */ #define SEEN_VREG_MASK 0x1ff80000 /* Volatile registers r3-r12 */ #define SEEN_NVREG_MASK 0x0003ffff /* Non volatile registers r14-r31 */ @@ -151,8 +150,15 @@ struct codegen_context { unsigned int idx; unsigned int stack_size; int b2p[ARRAY_SIZE(b2p)]; + unsigned int exentry_idx; }; +#ifdef CONFIG_PPC32 +#define BPF_FIXUP_LEN 3 /* Three instructions => 12 bytes */ +#else +#define BPF_FIXUP_LEN 2 /* Two instructions => 8 bytes */ +#endif + static inline void bpf_flush_icache(void *start, void *end) { smp_wmb(); /* smp write barrier */ @@ -176,11 +182,14 @@ static inline void bpf_clear_seen_register(struct codegen_context *ctx, int i) void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func); int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, - u32 *addrs, bool extra_pass); + u32 *addrs, int pass); void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx); void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx); void bpf_jit_realloc_regs(struct codegen_context *ctx); +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx, + int insn_idx, int jmp_off, int dst_reg); + #endif #endif diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index 90ce75f0f1e2..56dd1f4e3e44 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -23,15 +23,15 @@ static void bpf_jit_fill_ill_insns(void *area, unsigned int size) memset32(area, BREAKPOINT_INSTRUCTION, size / 4); } -/* Fix the branch target addresses for subprog calls */ -static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image, - struct codegen_context *ctx, u32 *addrs) +/* Fix updated addresses (for subprog calls, ldimm64, et al) during extra pass */ +static int bpf_jit_fixup_addresses(struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx, u32 *addrs) { const struct bpf_insn *insn = fp->insnsi; bool func_addr_fixed; u64 func_addr; u32 tmp_idx; - int i, ret; + int i, j, ret; for (i = 0; i < fp->len; i++) { /* @@ -66,6 +66,23 @@ static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image, * of the JITed sequence remains unchanged. */ ctx->idx = tmp_idx; + } else if (insn[i].code == (BPF_LD | BPF_IMM | BPF_DW)) { + tmp_idx = ctx->idx; + ctx->idx = addrs[i] / 4; +#ifdef CONFIG_PPC32 + PPC_LI32(ctx->b2p[insn[i].dst_reg] - 1, (u32)insn[i + 1].imm); + PPC_LI32(ctx->b2p[insn[i].dst_reg], (u32)insn[i].imm); + for (j = ctx->idx - addrs[i] / 4; j < 4; j++) + EMIT(PPC_RAW_NOP()); +#else + func_addr = ((u64)(u32)insn[i].imm) | (((u64)(u32)insn[i + 1].imm) << 32); + PPC_LI64(b2p[insn[i].dst_reg], func_addr); + /* overwrite rest with nops */ + for (j = ctx->idx - addrs[i] / 4; j < 5; j++) + EMIT(PPC_RAW_NOP()); +#endif + ctx->idx = tmp_idx; + i++; } } @@ -101,6 +118,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) struct bpf_prog *tmp_fp; bool bpf_blinded = false; bool extra_pass = false; + u32 extable_len; + u32 fixup_len; if (!fp->jit_requested) return org_fp; @@ -131,7 +150,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) image = jit_data->image; bpf_hdr = jit_data->header; proglen = jit_data->proglen; - alloclen = proglen + FUNCTION_DESCR_SIZE; extra_pass = true; goto skip_init_ctx; } @@ -149,7 +167,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) cgctx.stack_size = round_up(fp->aux->stack_depth, 16); /* Scouting faux-generate pass 0 */ - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0)) { /* We hit something illegal or unsupported. */ fp = org_fp; goto out_addrs; @@ -162,7 +180,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) */ if (cgctx.seen & SEEN_TAILCALL) { cgctx.idx = 0; - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0)) { fp = org_fp; goto out_addrs; } @@ -177,8 +195,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) bpf_jit_build_prologue(0, &cgctx); bpf_jit_build_epilogue(0, &cgctx); + fixup_len = fp->aux->num_exentries * BPF_FIXUP_LEN * 4; + extable_len = fp->aux->num_exentries * sizeof(struct exception_table_entry); + proglen = cgctx.idx * 4; - alloclen = proglen + FUNCTION_DESCR_SIZE; + alloclen = proglen + FUNCTION_DESCR_SIZE + fixup_len + extable_len; bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, bpf_jit_fill_ill_insns); if (!bpf_hdr) { @@ -186,6 +207,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) goto out_addrs; } + if (extable_len) + fp->aux->extable = (void *)image + FUNCTION_DESCR_SIZE + proglen + fixup_len; + skip_init_ctx: code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); @@ -193,13 +217,13 @@ skip_init_ctx: /* * Do not touch the prologue and epilogue as they will remain * unchanged. Only fix the branch target address for subprog - * calls in the body. + * calls in the body, and ldimm64 instructions. * * This does not change the offsets and lengths of the subprog * call instruction sequences and hence, the size of the JITed * image as well. */ - bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs); + bpf_jit_fixup_addresses(fp, code_base, &cgctx, addrs); /* There is no need to perform the usual passes. */ goto skip_codegen_passes; @@ -210,7 +234,7 @@ skip_init_ctx: /* Now build the prologue, body code & epilogue for real. */ cgctx.idx = 0; bpf_jit_build_prologue(code_base, &cgctx); - if (bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass)) { + if (bpf_jit_build_body(fp, code_base, &cgctx, addrs, pass)) { bpf_jit_binary_free(bpf_hdr); fp = org_fp; goto out_addrs; @@ -238,7 +262,7 @@ skip_codegen_passes: fp->bpf_func = (void *)image; fp->jited = 1; - fp->jited_len = alloclen; + fp->jited_len = proglen + FUNCTION_DESCR_SIZE; bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE)); if (!fp->is_func || extra_pass) { @@ -262,3 +286,52 @@ out: return fp; } + +/* + * The caller should check for (BPF_MODE(code) == BPF_PROBE_MEM) before calling + * this function, as this only applies to BPF_PROBE_MEM, for now. + */ +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx, + int insn_idx, int jmp_off, int dst_reg) +{ + off_t offset; + unsigned long pc; + struct exception_table_entry *ex; + u32 *fixup; + + /* Populate extable entries only in the last pass */ + if (pass != 2) + return 0; + + if (!fp->aux->extable || + WARN_ON_ONCE(ctx->exentry_idx >= fp->aux->num_exentries)) + return -EINVAL; + + pc = (unsigned long)&image[insn_idx]; + + fixup = (void *)fp->aux->extable - + (fp->aux->num_exentries * BPF_FIXUP_LEN * 4) + + (ctx->exentry_idx * BPF_FIXUP_LEN * 4); + + fixup[0] = PPC_RAW_LI(dst_reg, 0); + if (IS_ENABLED(CONFIG_PPC32)) + fixup[1] = PPC_RAW_LI(dst_reg - 1, 0); /* clear higher 32-bit register too */ + + fixup[BPF_FIXUP_LEN - 1] = + PPC_RAW_BRANCH((long)(pc + jmp_off) - (long)&fixup[BPF_FIXUP_LEN - 1]); + + ex = &fp->aux->extable[ctx->exentry_idx]; + + offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + return -ERANGE; + ex->insn = offset; + + offset = (long)fixup - (long)&ex->fixup; + if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + return -ERANGE; + ex->fixup = offset; + + ctx->exentry_idx++; + return 0; +} diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 0da31d41d413..cf8dd8aea386 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -191,6 +191,9 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun if (image && rel < 0x2000000 && rel >= -0x2000000) { PPC_BL_ABS(func); + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_NOP()); } else { /* Load function address into r0 */ EMIT(PPC_RAW_LIS(_R0, IMM_H(func))); @@ -221,13 +224,13 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o PPC_BCC(COND_GE, out); /* - * if (tail_call_cnt > MAX_TAIL_CALL_CNT) + * if (tail_call_cnt >= MAX_TAIL_CALL_CNT) * goto out; */ EMIT(PPC_RAW_CMPLWI(_R0, MAX_TAIL_CALL_CNT)); /* tail_call_cnt++; */ EMIT(PPC_RAW_ADDIC(_R0, _R0, 1)); - PPC_BCC(COND_GT, out); + PPC_BCC(COND_GE, out); /* prog = array->ptrs[index]; */ EMIT(PPC_RAW_RLWINM(_R3, b2p_index, 2, 0, 29)); @@ -268,7 +271,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o /* Assemble the body code between the prologue & epilogue */ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, - u32 *addrs, bool extra_pass) + u32 *addrs, int pass) { const struct bpf_insn *insn = fp->insnsi; int flen = fp->len; @@ -284,11 +287,14 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 src_reg = bpf_to_ppc(ctx, insn[i].src_reg); u32 src_reg_h = src_reg - 1; u32 tmp_reg = bpf_to_ppc(ctx, TMP_REG); + u32 size = BPF_SIZE(code); s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed; u64 func_addr; u32 true_cond; + u32 tmp_idx; + int j; /* * addrs[] maps a BPF bytecode address into a real offset from @@ -812,23 +818,91 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * * BPF_LDX */ case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */ - EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_B: case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ - EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_H: case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); - if (!fp->aux->verifier_zext) - EMIT(PPC_RAW_LI(dst_reg_h, 0)); - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_W: case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ - EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off)); - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4)); + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + /* + * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid + * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM + * load only if addr is kernel address (see is_kernel_addr()), otherwise + * set dst_reg=0 and move on. + */ + if (BPF_MODE(code) == BPF_PROBE_MEM) { + PPC_LI32(_R0, TASK_SIZE - off); + EMIT(PPC_RAW_CMPLW(src_reg, _R0)); + PPC_BCC(COND_GT, (ctx->idx + 5) * 4); + EMIT(PPC_RAW_LI(dst_reg, 0)); + /* + * For BPF_DW case, "li reg_h,0" would be needed when + * !fp->aux->verifier_zext. Emit NOP otherwise. + * + * Note that "li reg_h,0" is emitted for BPF_B/H/W case, + * if necessary. So, jump there insted of emitting an + * additional "li reg_h,0" instruction. + */ + if (size == BPF_DW && !fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + else + EMIT(PPC_RAW_NOP()); + /* + * Need to jump two instructions instead of one for BPF_DW case + * as there are two load instructions for dst_reg_h & dst_reg + * respectively. + */ + if (size == BPF_DW) + PPC_JMP((ctx->idx + 3) * 4); + else + PPC_JMP((ctx->idx + 2) * 4); + } + + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off)); + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4)); + break; + } + + if (size != BPF_DW && !fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + + if (BPF_MODE(code) == BPF_PROBE_MEM) { + int insn_idx = ctx->idx - 1; + int jmp_off = 4; + + /* + * In case of BPF_DW, two lwz instructions are emitted, one + * for higher 32-bit and another for lower 32-bit. So, set + * ex->insn to the first of the two and jump over both + * instructions in fixup. + * + * Similarly, with !verifier_zext, two instructions are + * emitted for BPF_B/H/W case. So, set ex->insn to the + * instruction that could fault and skip over both + * instructions. + */ + if (size == BPF_DW || !fp->aux->verifier_zext) { + insn_idx -= 1; + jmp_off += 4; + } + + ret = bpf_add_extable_entry(fp, image, pass, ctx, insn_idx, + jmp_off, dst_reg); + if (ret) + return ret; + } break; /* @@ -836,8 +910,12 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * * 16 byte instruction that uses two 'struct bpf_insn' */ case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ + tmp_idx = ctx->idx; PPC_LI32(dst_reg_h, (u32)insn[i + 1].imm); PPC_LI32(dst_reg, (u32)insn[i].imm); + /* padding to allow full 4 instructions for later patching */ + for (j = ctx->idx - tmp_idx; j < 4; j++) + EMIT(PPC_RAW_NOP()); /* Adjust for two bpf instructions */ addrs[++i] = ctx->idx * 4; break; @@ -862,7 +940,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * case BPF_JMP | BPF_CALL: ctx->seen |= SEEN_FUNC; - ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, + ret = bpf_jit_get_func_addr(fp, &insn[i], false, &func_addr, &func_addr_fixed); if (ret < 0) return ret; diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 8b5157ccfeba..e1e8c934308a 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -228,12 +228,12 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o PPC_BCC(COND_GE, out); /* - * if (tail_call_cnt > MAX_TAIL_CALL_CNT) + * if (tail_call_cnt >= MAX_TAIL_CALL_CNT) * goto out; */ PPC_BPF_LL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); EMIT(PPC_RAW_CMPLWI(b2p[TMP_REG_1], MAX_TAIL_CALL_CNT)); - PPC_BCC(COND_GT, out); + PPC_BCC(COND_GE, out); /* * tail_call_cnt++; @@ -297,7 +297,7 @@ asm ( /* Assemble the body code between the prologue & epilogue */ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, - u32 *addrs, bool extra_pass) + u32 *addrs, int pass) { enum stf_barrier_type stf_barrier = stf_barrier_type_get(); const struct bpf_insn *insn = fp->insnsi; @@ -311,6 +311,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 code = insn[i].code; u32 dst_reg = b2p[insn[i].dst_reg]; u32 src_reg = b2p[insn[i].src_reg]; + u32 size = BPF_SIZE(code); s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed; @@ -318,6 +319,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u64 imm64; u32 true_cond; u32 tmp_idx; + int j; /* * addrs[] maps a BPF bytecode address into a real offset from @@ -632,17 +634,21 @@ bpf_alu32_trunc: EMIT(PPC_RAW_MR(dst_reg, b2p[TMP_REG_1])); break; case 64: - /* - * Way easier and faster(?) to store the value - * into stack and then use ldbrx - * - * ctx->seen will be reliable in pass2, but - * the instructions generated will remain the - * same across all passes - */ + /* Store the value to stack and then use byte-reverse loads */ PPC_BPF_STL(dst_reg, 1, bpf_jit_stack_local(ctx)); EMIT(PPC_RAW_ADDI(b2p[TMP_REG_1], 1, bpf_jit_stack_local(ctx))); - EMIT(PPC_RAW_LDBRX(dst_reg, 0, b2p[TMP_REG_1])); + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + EMIT(PPC_RAW_LDBRX(dst_reg, 0, b2p[TMP_REG_1])); + } else { + EMIT(PPC_RAW_LWBRX(dst_reg, 0, b2p[TMP_REG_1])); + if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) + EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32)); + EMIT(PPC_RAW_LI(b2p[TMP_REG_2], 4)); + EMIT(PPC_RAW_LWBRX(b2p[TMP_REG_2], b2p[TMP_REG_2], b2p[TMP_REG_1])); + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + EMIT(PPC_RAW_SLDI(b2p[TMP_REG_2], b2p[TMP_REG_2], 32)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, b2p[TMP_REG_2])); + } break; } break; @@ -778,25 +784,66 @@ emit_clear: */ /* dst = *(u8 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_B: - EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_B: /* dst = *(u16 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_H: - EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_H: /* dst = *(u32 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_W: - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); - if (insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; - break; + case BPF_LDX | BPF_PROBE_MEM | BPF_W: /* dst = *(u64 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_DW: - PPC_BPF_LL(dst_reg, src_reg, off); + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + /* + * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid + * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM + * load only if addr is kernel address (see is_kernel_addr()), otherwise + * set dst_reg=0 and move on. + */ + if (BPF_MODE(code) == BPF_PROBE_MEM) { + EMIT(PPC_RAW_ADDI(b2p[TMP_REG_1], src_reg, off)); + if (IS_ENABLED(CONFIG_PPC_BOOK3E_64)) + PPC_LI64(b2p[TMP_REG_2], 0x8000000000000000ul); + else /* BOOK3S_64 */ + PPC_LI64(b2p[TMP_REG_2], PAGE_OFFSET); + EMIT(PPC_RAW_CMPLD(b2p[TMP_REG_1], b2p[TMP_REG_2])); + PPC_BCC(COND_GT, (ctx->idx + 4) * 4); + EMIT(PPC_RAW_LI(dst_reg, 0)); + /* + * Check if 'off' is word aligned because PPC_BPF_LL() + * (BPF_DW case) generates two instructions if 'off' is not + * word-aligned and one instruction otherwise. + */ + if (BPF_SIZE(code) == BPF_DW && (off & 3)) + PPC_JMP((ctx->idx + 3) * 4); + else + PPC_JMP((ctx->idx + 2) * 4); + } + + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + PPC_BPF_LL(dst_reg, src_reg, off); + break; + } + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + + if (BPF_MODE(code) == BPF_PROBE_MEM) { + ret = bpf_add_extable_entry(fp, image, pass, ctx, ctx->idx - 1, + 4, dst_reg); + if (ret) + return ret; + } break; /* @@ -806,9 +853,13 @@ emit_clear: case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ imm64 = ((u64)(u32) insn[i].imm) | (((u64)(u32) insn[i+1].imm) << 32); + tmp_idx = ctx->idx; + PPC_LI64(dst_reg, imm64); + /* padding to allow full 5 instructions for later patching */ + for (j = ctx->idx - tmp_idx; j < 5; j++) + EMIT(PPC_RAW_NOP()); /* Adjust for two bpf instructions */ addrs[++i] = ctx->idx * 4; - PPC_LI64(dst_reg, imm64); break; /* @@ -831,7 +882,7 @@ emit_clear: case BPF_JMP | BPF_CALL: ctx->seen |= SEEN_FUNC; - ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, + ret = bpf_jit_get_func_addr(fp, &insn[i], false, &func_addr, &func_addr_fixed); if (ret < 0) return ret; |