diff options
Diffstat (limited to 'arch/powerpc/net/bpf_jit_comp64.c')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 87 |
1 files changed, 33 insertions, 54 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 2cbcdf93cc19..5daa77aee7f7 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -84,7 +84,7 @@ 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 ] <------------- * [ ... ] | @@ -92,7 +92,7 @@ static inline bool bpf_has_stack_frame(struct codegen_context *ctx) * [ nv gpr save area ] 5*8 * [ tail_call_cnt ] 8 * [ local_tmp_var ] 16 - * [ unused red zone ] 208 bytes protected + * [ unused red zone ] 224 */ static int bpf_jit_stack_local(struct codegen_context *ctx) { @@ -126,6 +126,9 @@ 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))); @@ -200,21 +203,38 @@ 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, u32 *fimage, 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(!kernel_text_address(func_addr))) - return -EINVAL; + /* 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; + } #ifdef CONFIG_PPC_KERNEL_PCREL reladdr = func_addr - local_paca->kernelbase; - if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) { + /* + * If fimage is NULL (the initial pass to find image size), + * account for the maximum no. of instructions possible. + */ + 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)) @@ -266,7 +286,8 @@ bpf_jit_emit_func_call_hlp(u32 *image, u32 *fimage, struct codegen_context *ctx, * We can clobber r2 since we get called through a * function pointer (so caller will save/restore r2). */ - EMIT(PPC_RAW_LD(_R2, bpf_to_ppc(TMP_REG_2), 8)); + 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)); @@ -276,46 +297,14 @@ bpf_jit_emit_func_call_hlp(u32 *image, u32 *fimage, struct codegen_context *ctx, * Load r2 with kernel TOC as kernel TOC is used if function address falls * within core kernel text. */ - EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); + if (is_module_text_address(func_addr)) + EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); } #endif return 0; } -int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, 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; - - /* 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 increase, - * 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 (!image) - for (i = ctx->idx - ctx_idx; i < 5; i++) - EMIT(PPC_RAW_NOP()); - - EMIT(PPC_RAW_MTCTR(_R12)); - EMIT(PPC_RAW_BCTRL()); - - return 0; -} - static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) { /* @@ -326,7 +315,7 @@ 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_PPC_KERNEL_PCREL) && IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) bpf_tailcall_prologue_size += 4; /* skip past the toc load */ @@ -430,7 +419,6 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code u64 imm64; u32 true_cond; u32 tmp_idx; - int j; /* * addrs[] maps a BPF bytecode address into a real offset from @@ -1064,12 +1052,7 @@ 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 */ - if (!image) - for (j = ctx->idx - tmp_idx; j < 5; j++) - EMIT(PPC_RAW_NOP()); /* Adjust for two bpf instructions */ addrs[++i] = ctx->idx * 4; break; @@ -1102,11 +1085,7 @@ emit_clear: if (ret < 0) return ret; - if (func_addr_fixed) - ret = bpf_jit_emit_func_call_hlp(image, fimage, ctx, func_addr); - else - ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); - + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); if (ret) return ret; |