diff options
Diffstat (limited to 'arch/powerpc/net')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 161 |
1 files changed, 141 insertions, 20 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 5daa77aee7f7..025524378443 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -370,6 +370,23 @@ 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() @@ -392,11 +409,77 @@ asm ( " blr ;" ); +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, 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; @@ -789,30 +872,51 @@ 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; /* @@ -859,8 +963,25 @@ emit_clear: /* * 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: + if (bpf_atomic_is_load_store(&insn[i])) { + ret = emit_atomic_ld_st(insn[i], ctx, image); + if (ret) + return ret; + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + } else if (size == BPF_B || size == BPF_H) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + return -EOPNOTSUPP; + } + save_reg = tmp2_reg; ret_reg = src_reg; |