From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3C94CC27C79 for ; Thu, 20 Jun 2024 19:10:27 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=uSk2QqIL; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4W4qnX4Zznz3cZn for ; Fri, 21 Jun 2024 05:10:24 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=uSk2QqIL; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4641:c500::1; helo=dfw.source.kernel.org; envelope-from=naveen@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4W4qml4XZ1z3cVB for ; Fri, 21 Jun 2024 05:09:43 +1000 (AEST) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A6A3162265; Thu, 20 Jun 2024 19:09:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80241C2BD10; Thu, 20 Jun 2024 19:09:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718910582; bh=H8nf7tfD5oT/6PWOmbgyxWoLMQxlwQFGYGkHr7dxa64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uSk2QqILNZieTS1eCmaJ9OksCEvdPA04YDPLi+lJY/yhtYNoJ3bYo2pdhR9R5ZlOh x0FJHikNVELPugwWcYaLfjeGz7EB2L5H/FUkCdkqhOq/sF4ddkoT5n+PiGyz43I55F sSU45m3FVxC8vHbPG1rzmDr1NdXtmr2XJMjXKA6rL0FBlDA6mmhps1rPy1vJd/ptYz nDh1MyXmwGBXhI265C7jFthCckzyLDAcXZk/rKz2SGNZEraQmWs2Y7ZsJV90GD8DGH QRtAzWGMMTmOAGxNdGF0q0T8sey+MWgG3Dr2e1214VzLYxVpUJjJy+jPwjXSCV1n7s 3E8/rWhHB8PnQ== From: Naveen N Rao To: , , Subject: [RFC PATCH v3 10/11] powerpc64/bpf: Fold bpf_jit_emit_func_call_hlp() into bpf_jit_emit_func_call_rel() Date: Fri, 21 Jun 2024 00:39:10 +0530 Message-ID: X-Mailer: git-send-email 2.45.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Daniel Borkmann , Masahiro Yamada , John Fastabend , Alexei Starovoitov , Christophe Leroy , Andrii Nakryiko , Song Liu , Steven Rostedt , Nicholas Piggin , Jiri Olsa , Masami Hiramatsu Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Commit 61688a82e047 ("powerpc/bpf: enable kfunc call") enhanced bpf_jit_emit_func_call_hlp() to handle calls out to module region, where bpf progs are generated. The only difference now between bpf_jit_emit_func_call_hlp() and bpf_jit_emit_func_call_rel() is in handling of the initial pass where target function address is not known. Fold that logic into bpf_jit_emit_func_call_hlp() and rename it to bpf_jit_emit_func_call_rel() to simplify bpf function call JIT code. We don't actually need to load/restore TOC across a call out to a different kernel helper or to a different bpf program since they all work with the kernel TOC. We only need to do it if we have to call out to a module function. So, guard TOC load/restore with appropriate conditions. Signed-off-by: Naveen N Rao --- arch/powerpc/net/bpf_jit_comp64.c | 61 +++++++++---------------------- 1 file changed, 17 insertions(+), 44 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 7703dcf48be8..288ff32d676f 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -202,14 +202,22 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_BLR()); } -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; @@ -266,7 +274,8 @@ 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 +285,14 @@ 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) { /* @@ -1047,11 +1024,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code 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; -- 2.45.2