diff options
Diffstat (limited to 'arch/powerpc/net/bpf_jit_comp64.c')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 788 |
1 files changed, 605 insertions, 183 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 29ee306d6302..1fe37128c876 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -25,18 +25,18 @@ * with our redzone usage. * * [ prev sp ] <------------- - * [ nv gpr save area ] 5*8 | + * [ nv gpr save area ] 6*8 | * [ tail_call_cnt ] 8 | - * [ local_tmp_var ] 16 | + * [ local_tmp_var ] 24 | * fp (r31) --> [ ebpf stack space ] upto 512 | * [ frame header ] 32/112 | * sp (r1) ---> [ stack pointer ] -------------- */ /* for gpr non volatile registers BPG_REG_6 to 10 */ -#define BPF_PPC_STACK_SAVE (5*8) +#define BPF_PPC_STACK_SAVE (6*8) /* for bpf JIT code internal usage */ -#define BPF_PPC_STACK_LOCALS 24 +#define BPF_PPC_STACK_LOCALS 32 /* stack frame excluding BPF stack, ensure this is quadword aligned */ #define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \ BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE) @@ -44,6 +44,7 @@ /* BPF register usage */ #define TMP_REG_1 (MAX_BPF_JIT_REG + 0) #define TMP_REG_2 (MAX_BPF_JIT_REG + 1) +#define ARENA_VM_START (MAX_BPF_JIT_REG + 2) /* BPF to ppc register mappings */ void bpf_jit_init_reg_mapping(struct codegen_context *ctx) @@ -67,10 +68,12 @@ void bpf_jit_init_reg_mapping(struct codegen_context *ctx) ctx->b2p[BPF_REG_AX] = _R12; ctx->b2p[TMP_REG_1] = _R9; ctx->b2p[TMP_REG_2] = _R10; + /* non volatile register for kern_vm_start address */ + ctx->b2p[ARENA_VM_START] = _R26; } -/* PPC NVR range -- update this if we ever use NVRs below r27 */ -#define BPF_PPC_NVR_MIN _R27 +/* PPC NVR range -- update this if we ever use NVRs below r26 */ +#define BPF_PPC_NVR_MIN _R26 static inline bool bpf_has_stack_frame(struct codegen_context *ctx) { @@ -84,27 +87,27 @@ static inline bool bpf_has_stack_frame(struct codegen_context *ctx) } /* - * When not setting up our own stackframe, the redzone usage is: + * When not setting up our own stackframe, the redzone (288 bytes) usage is: * * [ prev sp ] <------------- * [ ... ] | * sp (r1) ---> [ stack pointer ] -------------- - * [ nv gpr save area ] 5*8 + * [ nv gpr save area ] 6*8 * [ tail_call_cnt ] 8 - * [ local_tmp_var ] 16 - * [ unused red zone ] 208 bytes protected + * [ local_tmp_var ] 24 + * [ unused red zone ] 224 */ static int bpf_jit_stack_local(struct codegen_context *ctx) { if (bpf_has_stack_frame(ctx)) return STACK_FRAME_MIN_SIZE + ctx->stack_size; else - return -(BPF_PPC_STACK_SAVE + 24); + return -(BPF_PPC_STACK_SAVE + 32); } static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx) { - return bpf_jit_stack_local(ctx) + 16; + return bpf_jit_stack_local(ctx) + 24; } static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) @@ -126,8 +129,13 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) { int i; + /* Instruction for trampoline attach */ + EMIT(PPC_RAW_NOP()); + +#ifndef CONFIG_PPC_KERNEL_PCREL if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); +#endif /* * Initialize tail_call_cnt if we do tail calls. @@ -165,10 +173,17 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) if (bpf_is_seen_register(ctx, bpf_to_ppc(i))) EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i)))); + if (ctx->arena_vm_start) + EMIT(PPC_RAW_STD(bpf_to_ppc(ARENA_VM_START), _R1, + bpf_jit_stack_offsetof(ctx, bpf_to_ppc(ARENA_VM_START)))); + /* Setup frame pointer to point to the bpf stack area */ if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1, STACK_FRAME_MIN_SIZE + ctx->stack_size)); + + if (ctx->arena_vm_start) + PPC_LI64(bpf_to_ppc(ARENA_VM_START), ctx->arena_vm_start); } static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx) @@ -180,6 +195,10 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx if (bpf_is_seen_register(ctx, bpf_to_ppc(i))) EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i)))); + if (ctx->arena_vm_start) + EMIT(PPC_RAW_LD(bpf_to_ppc(ARENA_VM_START), _R1, + bpf_jit_stack_offsetof(ctx, bpf_to_ppc(ARENA_VM_START)))); + /* Tear down our stack frame */ if (bpf_has_stack_frame(ctx)) { EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size)); @@ -198,58 +217,104 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); EMIT(PPC_RAW_BLR()); + + bpf_jit_build_fentry_stubs(image, ctx); } -static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u64 func) +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) { unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0; long reladdr; - if (WARN_ON_ONCE(!core_kernel_text(func_addr))) - return -EINVAL; - - reladdr = func_addr - kernel_toc_addr(); - if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { - pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func); - return -ERANGE; + /* bpf to bpf call, func is not known in the initial pass. Emit 5 nops as a placeholder */ + if (!func) { + for (int i = 0; i < 5; i++) + EMIT(PPC_RAW_NOP()); + /* elfv1 needs an additional instruction to load addr from descriptor */ + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + return 0; } - EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr))); - EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr))); - EMIT(PPC_RAW_MTCTR(_R12)); - EMIT(PPC_RAW_BCTRL()); - - return 0; -} - -int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) -{ - unsigned int i, ctx_idx = ctx->idx; - - if (WARN_ON_ONCE(func && is_module_text_address(func))) - return -EINVAL; +#ifdef CONFIG_PPC_KERNEL_PCREL + reladdr = func_addr - local_paca->kernelbase; - /* skip past descriptor if elf v1 */ - func += FUNCTION_DESCR_SIZE; - - /* Load function address into r12 */ - PPC_LI64(_R12, func); - - /* For bpf-to-bpf function calls, the callee's address is unknown - * until the last extra pass. As seen above, we use PPC_LI64() to - * load the callee's address, but this may optimize the number of - * instructions required based on the nature of the address. - * - * Since we don't want the number of instructions emitted to change, - * we pad the optimized PPC_LI64() call with NOPs to guarantee that - * we always have a five-instruction sequence, which is the maximum - * that PPC_LI64() can emit. + /* + * If fimage is NULL (the initial pass to find image size), + * account for the maximum no. of instructions possible. */ - for (i = ctx->idx - ctx_idx; i < 5; i++) - EMIT(PPC_RAW_NOP()); + if (!fimage) { + ctx->idx += 7; + return 0; + } else if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) { + EMIT(PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernelbase))); + /* Align for subsequent prefix instruction */ + if (!IS_ALIGNED((unsigned long)fimage + CTX_NIA(ctx), 8)) + EMIT(PPC_RAW_NOP()); + /* paddi r12,r12,addr */ + EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(0) | IMM_H18(reladdr)); + EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | ___PPC_RA(_R12) | IMM_L(reladdr)); + } else { + unsigned long pc = (unsigned long)fimage + CTX_NIA(ctx); + bool alignment_needed = !IS_ALIGNED(pc, 8); + + reladdr = func_addr - (alignment_needed ? pc + 4 : pc); + if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) { + if (alignment_needed) + EMIT(PPC_RAW_NOP()); + /* pla r12,addr */ + EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(1) | IMM_H18(reladdr)); + EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | IMM_L(reladdr)); + } else { + /* We can clobber r12 */ + PPC_LI64(_R12, func); + } + } EMIT(PPC_RAW_MTCTR(_R12)); EMIT(PPC_RAW_BCTRL()); +#else + if (core_kernel_text(func_addr)) { + reladdr = func_addr - kernel_toc_addr(); + if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { + pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func); + return -ERANGE; + } + + EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr))); + EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr))); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + } else { + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) { + /* func points to the function descriptor */ + PPC_LI64(bpf_to_ppc(TMP_REG_2), func); + /* Load actual entry point from function descriptor */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), 0)); + /* ... and move it to CTR */ + EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1))); + /* + * Load TOC from function descriptor at offset 8. + * We can clobber r2 since we get called through a + * function pointer (so caller will save/restore r2). + */ + if (is_module_text_address(func_addr)) + EMIT(PPC_RAW_LD(_R2, bpf_to_ppc(TMP_REG_2), 8)); + } else { + PPC_LI64(_R12, func); + EMIT(PPC_RAW_MTCTR(_R12)); + } + EMIT(PPC_RAW_BCTRL()); + /* + * Load r2 with kernel TOC as kernel TOC is used if function address falls + * within core kernel text. + */ + if (is_module_text_address(func_addr)) + EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); + } +#endif return 0; } @@ -264,9 +329,9 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o */ int b2p_bpf_array = bpf_to_ppc(BPF_REG_2); int b2p_index = bpf_to_ppc(BPF_REG_3); - int bpf_tailcall_prologue_size = 8; + int bpf_tailcall_prologue_size = 12; - if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) + if (!IS_ENABLED(CONFIG_PPC_KERNEL_PCREL) && IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) bpf_tailcall_prologue_size += 4; /* skip past the toc load */ /* @@ -319,6 +384,23 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o return 0; } +bool bpf_jit_bypass_spec_v1(void) +{ +#if defined(CONFIG_PPC_E500) || defined(CONFIG_PPC_BOOK3S_64) + return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && + security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)); +#else + return true; +#endif +} + +bool bpf_jit_bypass_spec_v4(void) +{ + return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && + security_ftr_enabled(SEC_FTR_STF_BARRIER) && + stf_barrier_type_get() != STF_BARRIER_NONE); +} + /* * We spill into the redzone always, even if the bpf program has its own stackframe. * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local() @@ -328,11 +410,11 @@ void bpf_stf_barrier(void); asm ( " .global bpf_stf_barrier ;" " bpf_stf_barrier: ;" -" std 21,-64(1) ;" -" std 22,-56(1) ;" +" std 21,-80(1) ;" +" std 22,-72(1) ;" " sync ;" -" ld 21,-64(1) ;" -" ld 22,-56(1) ;" +" ld 21,-80(1) ;" +" ld 22,-72(1) ;" " ori 31,31,0 ;" " .rept 14 ;" " b 1f ;" @@ -341,11 +423,212 @@ asm ( " blr ;" ); +static int bpf_jit_emit_atomic_ops(u32 *image, struct codegen_context *ctx, + const struct bpf_insn *insn, u32 *jmp_off, + u32 *tmp_idx, u32 *addrp) +{ + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + u32 size = BPF_SIZE(insn->code); + u32 src_reg = bpf_to_ppc(insn->src_reg); + u32 dst_reg = bpf_to_ppc(insn->dst_reg); + s32 imm = insn->imm; + + u32 save_reg = tmp2_reg; + u32 ret_reg = src_reg; + u32 fixup_idx; + + /* Get offset into TMP_REG_1 */ + EMIT(PPC_RAW_LI(tmp1_reg, insn->off)); + /* + * Enforce full ordering for operations with BPF_FETCH by emitting a 'sync' + * before and after the operation. + * + * This is a requirement in the Linux Kernel Memory Model. + * See __cmpxchg_u64() in asm/cmpxchg.h as an example. + */ + if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + + *tmp_idx = ctx->idx; + + /* load value from memory into TMP_REG_2 */ + if (size == BPF_DW) + EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + else + EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + /* Save old value in _R0 */ + if (imm & BPF_FETCH) + EMIT(PPC_RAW_MR(_R0, tmp2_reg)); + + switch (imm) { + case BPF_ADD: + case BPF_ADD | BPF_FETCH: + EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_AND: + case BPF_AND | BPF_FETCH: + EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_OR: + case BPF_OR | BPF_FETCH: + EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_XOR: + case BPF_XOR | BPF_FETCH: + EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_CMPXCHG: + /* + * Return old value in BPF_REG_0 for BPF_CMPXCHG & + * in src_reg for other cases. + */ + ret_reg = bpf_to_ppc(BPF_REG_0); + + /* Compare with old value in BPF_R0 */ + if (size == BPF_DW) + EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + else + EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + /* Don't set if different from old value */ + PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4); + fallthrough; + case BPF_XCHG: + save_reg = src_reg; + break; + default: + return -EOPNOTSUPP; + } + + /* store new value */ + if (size == BPF_DW) + EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg)); + else + EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg)); + /* we're done if this succeeded */ + PPC_BCC_SHORT(COND_NE, *tmp_idx * 4); + fixup_idx = ctx->idx; + + if (imm & BPF_FETCH) { + /* Emit 'sync' to enforce full ordering */ + if (IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + EMIT(PPC_RAW_MR(ret_reg, _R0)); + /* + * Skip unnecessary zero-extension for 32-bit cmpxchg. + * For context, see commit 39491867ace5. + */ + if (size != BPF_DW && imm == BPF_CMPXCHG && + insn_is_zext(insn + 1)) + *addrp = ctx->idx * 4; + } + + *jmp_off = (fixup_idx - *tmp_idx) * 4; + + return 0; +} + +static int bpf_jit_emit_probe_mem_store(struct codegen_context *ctx, u32 src_reg, s16 off, + u32 code, u32 *image) +{ + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + + switch (BPF_SIZE(code)) { + case BPF_B: + EMIT(PPC_RAW_STB(src_reg, tmp1_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_STH(src_reg, tmp1_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_STW(src_reg, tmp1_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_STDX(src_reg, tmp1_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_STD(src_reg, tmp1_reg, off)); + } + break; + default: + return -EINVAL; + } + return 0; +} + +static int emit_atomic_ld_st(const struct bpf_insn insn, struct codegen_context *ctx, u32 *image) +{ + u32 code = insn.code; + u32 dst_reg = bpf_to_ppc(insn.dst_reg); + u32 src_reg = bpf_to_ppc(insn.src_reg); + u32 size = BPF_SIZE(code); + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + s16 off = insn.off; + s32 imm = insn.imm; + + switch (imm) { + case BPF_LOAD_ACQ: + 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: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp1_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg)); + } else { + EMIT(PPC_RAW_LD(dst_reg, src_reg, off)); + } + break; + } + EMIT(PPC_RAW_LWSYNC()); + break; + case BPF_STORE_REL: + EMIT(PPC_RAW_LWSYNC()); + switch (size) { + case BPF_B: + EMIT(PPC_RAW_STB(src_reg, dst_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_STH(src_reg, dst_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_STW(src_reg, dst_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_STD(src_reg, dst_reg, off)); + } + break; + } + break; + default: + pr_err_ratelimited("unexpected atomic load/store op code %02x\n", + imm); + return -EINVAL; + } + + return 0; +} + /* 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, int pass) +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, + u32 *addrs, int pass, bool extra_pass) { enum stf_barrier_type stf_barrier = stf_barrier_type_get(); + bool sync_emitted, ori31_emitted; const struct bpf_insn *insn = fp->insnsi; int flen = fp->len; int i, ret; @@ -360,7 +643,6 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 size = BPF_SIZE(code); u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); - u32 save_reg, ret_reg; s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed; @@ -368,7 +650,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u64 imm64; u32 true_cond; u32 tmp_idx; - int j; + u32 jmp_off; /* * addrs[] maps a BPF bytecode address into a real offset from @@ -448,20 +730,33 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ if (BPF_OP(code) == BPF_MOD) { - EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg)); + if (off) + EMIT(PPC_RAW_DIVW(tmp1_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg)); EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); } else - EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg)); + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg)); goto bpf_alu32_trunc; case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ if (BPF_OP(code) == BPF_MOD) { - EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg)); + if (off) + EMIT(PPC_RAW_DIVD(tmp1_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg)); EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg)); EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); } else - EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg)); + if (off) + EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg)); break; case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ @@ -482,19 +777,31 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * switch (BPF_CLASS(code)) { case BPF_ALU: if (BPF_OP(code) == BPF_MOD) { - EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg)); + if (off) + EMIT(PPC_RAW_DIVW(tmp2_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg)); EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg)); EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); } else - EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg)); + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg)); break; case BPF_ALU64: if (BPF_OP(code) == BPF_MOD) { - EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg)); + if (off) + EMIT(PPC_RAW_DIVD(tmp2_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg)); EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg)); EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); } else - EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg)); + if (off) + EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg)); break; } goto bpf_alu32_trunc; @@ -610,12 +917,28 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * */ case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + + if (insn_is_cast_user(&insn[i])) { + EMIT(PPC_RAW_RLDICL_DOT(tmp1_reg, src_reg, 0, 32)); + PPC_LI64(dst_reg, (ctx->user_vm_start & 0xffffffff00000000UL)); + PPC_BCC_SHORT(COND_EQ, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_OR(tmp1_reg, dst_reg, tmp1_reg)); + EMIT(PPC_RAW_MR(dst_reg, tmp1_reg)); + break; + } + if (imm == 1) { /* special mov32 for zext */ EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31)); break; - } - EMIT(PPC_RAW_MR(dst_reg, src_reg)); + } else if (off == 8) { + EMIT(PPC_RAW_EXTSB(dst_reg, src_reg)); + } else if (off == 16) { + EMIT(PPC_RAW_EXTSH(dst_reg, src_reg)); + } else if (off == 32) { + EMIT(PPC_RAW_EXTSW(dst_reg, src_reg)); + } else if (dst_reg != src_reg) + EMIT(PPC_RAW_MR(dst_reg, src_reg)); goto bpf_alu32_trunc; case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ @@ -637,11 +960,12 @@ bpf_alu32_trunc: */ case BPF_ALU | BPF_END | BPF_FROM_LE: case BPF_ALU | BPF_END | BPF_FROM_BE: + case BPF_ALU64 | BPF_END | BPF_FROM_LE: #ifdef __BIG_ENDIAN__ if (BPF_SRC(code) == BPF_FROM_BE) goto emit_clear; #else /* !__BIG_ENDIAN__ */ - if (BPF_SRC(code) == BPF_FROM_LE) + if (BPF_CLASS(code) == BPF_ALU && BPF_SRC(code) == BPF_FROM_LE) goto emit_clear; #endif switch (imm) { @@ -707,30 +1031,51 @@ emit_clear: /* * BPF_ST NOSPEC (speculation barrier) + * + * The following must act as a barrier against both Spectre v1 + * and v4 if we requested both mitigations. Therefore, also emit + * 'isync; sync' on E500 or 'ori31' on BOOK3S_64 in addition to + * the insns needed for a Spectre v4 barrier. + * + * If we requested only !bypass_spec_v1 OR only !bypass_spec_v4, + * we can skip the respective other barrier type as an + * optimization. */ case BPF_ST | BPF_NOSPEC: - if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) || - !security_ftr_enabled(SEC_FTR_STF_BARRIER)) - break; - - switch (stf_barrier) { - case STF_BARRIER_EIEIO: - EMIT(PPC_RAW_EIEIO() | 0x02000000); - break; - case STF_BARRIER_SYNC_ORI: + sync_emitted = false; + ori31_emitted = false; + if (IS_ENABLED(CONFIG_PPC_E500) && + !bpf_jit_bypass_spec_v1()) { + EMIT(PPC_RAW_ISYNC()); EMIT(PPC_RAW_SYNC()); - EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0)); - EMIT(PPC_RAW_ORI(_R31, _R31, 0)); - break; - case STF_BARRIER_FALLBACK: - ctx->seen |= SEEN_FUNC; - PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier)); - EMIT(PPC_RAW_MTCTR(_R12)); - EMIT(PPC_RAW_BCTRL()); - break; - case STF_BARRIER_NONE: - break; + sync_emitted = true; } + if (!bpf_jit_bypass_spec_v4()) { + switch (stf_barrier) { + case STF_BARRIER_EIEIO: + EMIT(PPC_RAW_EIEIO() | 0x02000000); + break; + case STF_BARRIER_SYNC_ORI: + if (!sync_emitted) + EMIT(PPC_RAW_SYNC()); + EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0)); + EMIT(PPC_RAW_ORI(_R31, _R31, 0)); + ori31_emitted = true; + break; + case STF_BARRIER_FALLBACK: + ctx->seen |= SEEN_FUNC; + PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier)); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + break; + case STF_BARRIER_NONE: + break; + } + } + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && + !bpf_jit_bypass_spec_v1() && + !ori31_emitted) + EMIT(PPC_RAW_ORI(_R31, _R31, 0)); break; /* @@ -774,86 +1119,107 @@ emit_clear: } break; + case BPF_STX | BPF_PROBE_MEM32 | BPF_B: + case BPF_STX | BPF_PROBE_MEM32 | BPF_H: + case BPF_STX | BPF_PROBE_MEM32 | BPF_W: + case BPF_STX | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + + ret = bpf_jit_emit_probe_mem_store(ctx, src_reg, off, code, image); + if (ret) + return ret; + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, -1, code); + if (ret) + return ret; + + break; + + case BPF_ST | BPF_PROBE_MEM32 | BPF_B: + case BPF_ST | BPF_PROBE_MEM32 | BPF_H: + case BPF_ST | BPF_PROBE_MEM32 | BPF_W: + case BPF_ST | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + + if (BPF_SIZE(code) == BPF_W || BPF_SIZE(code) == BPF_DW) { + PPC_LI32(tmp2_reg, imm); + src_reg = tmp2_reg; + } else { + EMIT(PPC_RAW_LI(tmp2_reg, imm)); + src_reg = tmp2_reg; + } + + ret = bpf_jit_emit_probe_mem_store(ctx, src_reg, off, code, image); + if (ret) + return ret; + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, -1, code); + if (ret) + return ret; + + break; + + /* + * BPF_STX PROBE_ATOMIC (arena atomic ops) + */ + case BPF_STX | BPF_PROBE_ATOMIC | BPF_W: + case BPF_STX | BPF_PROBE_ATOMIC | BPF_DW: + EMIT(PPC_RAW_ADD(dst_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + ret = bpf_jit_emit_atomic_ops(image, ctx, &insn[i], + &jmp_off, &tmp_idx, &addrs[i + 1]); + if (ret) { + if (ret == -EOPNOTSUPP) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + } + return ret; + } + /* LDARX/LWARX should land here on exception. */ + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + tmp_idx, jmp_off, dst_reg, code); + if (ret) + return ret; + + /* Retrieve the dst_reg */ + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + break; + /* * BPF_STX ATOMIC (atomic ops) */ + case BPF_STX | BPF_ATOMIC | BPF_B: + case BPF_STX | BPF_ATOMIC | BPF_H: case BPF_STX | BPF_ATOMIC | BPF_W: case BPF_STX | BPF_ATOMIC | BPF_DW: - save_reg = tmp2_reg; - ret_reg = src_reg; - - /* Get offset into TMP_REG_1 */ - EMIT(PPC_RAW_LI(tmp1_reg, off)); - tmp_idx = ctx->idx * 4; - /* load value from memory into TMP_REG_2 */ - if (size == BPF_DW) - EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0)); - else - EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0)); - - /* Save old value in _R0 */ - if (imm & BPF_FETCH) - EMIT(PPC_RAW_MR(_R0, tmp2_reg)); - - switch (imm) { - case BPF_ADD: - case BPF_ADD | BPF_FETCH: - EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); - break; - case BPF_AND: - case BPF_AND | BPF_FETCH: - EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg)); - break; - case BPF_OR: - case BPF_OR | BPF_FETCH: - EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg)); - break; - case BPF_XOR: - case BPF_XOR | BPF_FETCH: - EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg)); - break; - case BPF_CMPXCHG: - /* - * Return old value in BPF_REG_0 for BPF_CMPXCHG & - * in src_reg for other cases. - */ - ret_reg = bpf_to_ppc(BPF_REG_0); + if (bpf_atomic_is_load_store(&insn[i])) { + ret = emit_atomic_ld_st(insn[i], ctx, image); + if (ret) + return ret; - /* Compare with old value in BPF_R0 */ - if (size == BPF_DW) - EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg)); - else - EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg)); - /* Don't set if different from old value */ - PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4); - fallthrough; - case BPF_XCHG: - save_reg = src_reg; + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; break; - default: + } else if (size == BPF_B || size == BPF_H) { pr_err_ratelimited( "eBPF filter atomic op code %02x (@%d) unsupported\n", code, i); return -EOPNOTSUPP; } - /* store new value */ - if (size == BPF_DW) - EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg)); - else - EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg)); - /* we're done if this succeeded */ - PPC_BCC_SHORT(COND_NE, tmp_idx); - - if (imm & BPF_FETCH) { - EMIT(PPC_RAW_MR(ret_reg, _R0)); - /* - * Skip unnecessary zero-extension for 32-bit cmpxchg. - * For context, see commit 39491867ace5. - */ - if (size != BPF_DW && imm == BPF_CMPXCHG && - insn_is_zext(&insn[i + 1])) - addrs[++i] = ctx->idx * 4; + ret = bpf_jit_emit_atomic_ops(image, ctx, &insn[i], + &jmp_off, &tmp_idx, &addrs[i + 1]); + if (ret) { + if (ret == -EOPNOTSUPP) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + } + return ret; } break; @@ -862,13 +1228,19 @@ emit_clear: */ /* dst = *(u8 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEMSX | BPF_B: case BPF_LDX | BPF_PROBE_MEM | BPF_B: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: /* dst = *(u16 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEMSX | BPF_H: case BPF_LDX | BPF_PROBE_MEM | BPF_H: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: /* dst = *(u32 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEMSX | BPF_W: case BPF_LDX | BPF_PROBE_MEM | BPF_W: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: /* dst = *(u64 *)(ul) (src + off) */ case BPF_LDX | BPF_MEM | BPF_DW: case BPF_LDX | BPF_PROBE_MEM | BPF_DW: @@ -878,7 +1250,7 @@ emit_clear: * 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) { + if (BPF_MODE(code) == BPF_PROBE_MEM || BPF_MODE(code) == BPF_PROBE_MEMSX) { EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off)); if (IS_ENABLED(CONFIG_PPC_BOOK3E_64)) PPC_LI64(tmp2_reg, 0x8000000000000000ul); @@ -891,28 +1263,85 @@ emit_clear: * Check if 'off' is word aligned for BPF_DW, because * we might generate two instructions. */ - if (BPF_SIZE(code) == BPF_DW && (off & 3)) + if ((BPF_SIZE(code) == BPF_DW && (off & 3)) || + (BPF_SIZE(code) == BPF_B && + BPF_MODE(code) == BPF_PROBE_MEMSX) || + (BPF_SIZE(code) == BPF_B && BPF_MODE(code) == BPF_MEMSX)) PPC_JMP((ctx->idx + 3) * 4); else PPC_JMP((ctx->idx + 2) * 4); } + if (BPF_MODE(code) == BPF_MEMSX || BPF_MODE(code) == BPF_PROBE_MEMSX) { + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_EXTSB(dst_reg, dst_reg)); + break; + case BPF_H: + EMIT(PPC_RAW_LHA(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWA(dst_reg, src_reg, off)); + break; + } + } else { + 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: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp1_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg)); + } else { + EMIT(PPC_RAW_LD(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, fimage, pass, ctx, + ctx->idx - 1, 4, dst_reg, code); + if (ret) + return ret; + } + break; + + /* dst = *(u64 *)(ul) (src + ARENA_VM_START + off) */ + case BPF_LDX | BPF_PROBE_MEM32 | BPF_B: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_H: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_W: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, src_reg, bpf_to_ppc(ARENA_VM_START))); + switch (size) { case BPF_B: - EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_LBZ(dst_reg, tmp1_reg, off)); break; case BPF_H: - EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_LHZ(dst_reg, tmp1_reg, off)); break; case BPF_W: - EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_LWZ(dst_reg, tmp1_reg, off)); break; case BPF_DW: if (off % 4) { - EMIT(PPC_RAW_LI(tmp1_reg, off)); - EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg)); + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, tmp1_reg, tmp2_reg)); } else { - EMIT(PPC_RAW_LD(dst_reg, src_reg, off)); + EMIT(PPC_RAW_LD(dst_reg, tmp1_reg, off)); } break; } @@ -920,12 +1349,10 @@ emit_clear: 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; - } + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, dst_reg, code); + if (ret) + return ret; break; /* @@ -935,11 +1362,7 @@ 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; break; @@ -967,16 +1390,12 @@ emit_clear: case BPF_JMP | BPF_CALL: ctx->seen |= SEEN_FUNC; - ret = bpf_jit_get_func_addr(fp, &insn[i], false, + ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, &func_addr, &func_addr_fixed); if (ret < 0) return ret; - if (func_addr_fixed) - ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr); - else - ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr); - + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); if (ret) return ret; @@ -990,6 +1409,9 @@ emit_clear: case BPF_JMP | BPF_JA: PPC_JMP(addrs[i + 1 + off]); break; + case BPF_JMP32 | BPF_JA: + PPC_JMP(addrs[i + 1 + imm]); + break; case BPF_JMP | BPF_JGT | BPF_K: case BPF_JMP | BPF_JGT | BPF_X: |
