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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44891C43334 for ; Tue, 5 Jul 2022 19:03:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233163AbiGETDo (ORCPT ); Tue, 5 Jul 2022 15:03:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233148AbiGETDn (ORCPT ); Tue, 5 Jul 2022 15:03:43 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74FAF1EED9; Tue, 5 Jul 2022 12:03:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E1A2161A9D; Tue, 5 Jul 2022 19:03:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4F37C341CD; Tue, 5 Jul 2022 19:03:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657047821; bh=twXRGeflIiQLxPwsyCeS4+rA2mqh/YP2Rp+Kgb+cTUc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T+RnlzTolVuNxH7C1F4MFa1JcC/xxUDroV2a0SS2HP2LR4WmSF7UFNxsyQHYn+ozn 73bmDKGF9KiRAf1fyg3FFyIN1Tvcusw7CQzJgT9mhOu+RnlQc8PguDMp5+HMN8voFh qaMX80bq0f6/eqMaE/+b7rJqpoKh2xZX8XYmRqvjP/MqUyWS2OUIXtyo0+YfyJRjWm 9prqOZRoiXjMhj0pOyM6hxdQ9VHub53OpzBF0XwN4MI1ShL3PrKLtPnlKkDOptdlSO AQB37CS2IRzeWM8qhlwCy5qHzD48JgWdCroIAaoxOtlZbSCsWTLcUbZ8da0xmO2e36 BMGvJp7kzFQBQ== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Masami Hiramatsu , Martynas Pumputis , Yutaro Hayakawa Subject: [PATCH RFC bpf-next 2/4] bpf: Use given function address for trampoline ip arg Date: Tue, 5 Jul 2022 21:03:06 +0200 Message-Id: <20220705190308.1063813-3-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220705190308.1063813-1-jolsa@kernel.org> References: <20220705190308.1063813-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Using function address given at the generation time as the trampline ip argument. This way we don't need to read the ip from the stack and care about CONFIG_X86_KERNEL_IBT option. Signed-off-by: Jiri Olsa --- arch/x86/net/bpf_jit_comp.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 2f460c67f9c7..1d23dd51a42f 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -2015,13 +2015,14 @@ static bool is_valid_bpf_tramp_flags(unsigned int flags) int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end, const struct btf_func_model *m, u32 flags, struct bpf_tramp_links *tlinks, - void *orig_call) + void *func_addr) { int ret, i, nr_args = m->nr_args; int regs_off, ip_off, args_off, stack_size = nr_args * 8, run_ctx_off; struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY]; struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT]; struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN]; + void *orig_call = func_addr; u8 **branches = NULL; u8 *prog; bool save_ret; @@ -2097,12 +2098,10 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i if (flags & BPF_TRAMP_F_IP_ARG) { /* Store IP address of the traced function: - * mov rax, QWORD PTR [rbp + 8] - * sub rax, X86_PATCH_SIZE + * mov rax, func_addr * mov QWORD PTR [rbp - ip_off], rax */ - emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, 8); - EMIT4(0x48, 0x83, 0xe8, X86_PATCH_SIZE); + emit_mov_imm64(&prog, BPF_REG_0, (long) func_addr >> 32, (u32) (long) func_addr); emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -ip_off); } -- 2.35.3