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 0E368C32771 for ; Mon, 26 Sep 2022 16:46:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229702AbiIZQqM (ORCPT ); Mon, 26 Sep 2022 12:46:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229749AbiIZQpm (ORCPT ); Mon, 26 Sep 2022 12:45:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 488551166EA for ; Mon, 26 Sep 2022 08:34:18 -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 C75D260DFC for ; Mon, 26 Sep 2022 15:34:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0127EC433D6; Mon, 26 Sep 2022 15:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664206457; bh=8zHQ8a1AvPzozmCud6GCIR/pQsoPwADQwX+wZbl60Cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DhOgvj78+ztCiBt4lT0s8NOORqLOfwrrjq/jxCZut19TXtchuzXm3mlIpZkvxPL21 WRY8kjT3ypoU5s4wc5JA0a1pHzUTBsCep3SMnTghJWdGC+AS6Ou0oSs+/O2K9ez43/ jvRTz/hYKuuYKEVB5duzxDzu5It8M1aZIgv5Axn7I+Aa6VKCx6FuXaKni3bUg8oDWb zRtZzS1j1bkCJQBcZxnn6AZi07wkla7Xfd+u7VCn/vre4HjCvn8Mac442Ugl2QLxAh DhZDBgT8WYT9rSZTXuTUzCt7Z0JRYEgSVJXul47xXJb1KrrfBmlIWSBmADlsfa0MEe mCqrdtEwLfvVw== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , "Masami Hiramatsu (Google)" , Peter Zijlstra , Martynas Pumputis Subject: [PATCHv5 bpf-next 3/6] bpf: Use given function address for trampoline ip arg Date: Mon, 26 Sep 2022 17:33:37 +0200 Message-Id: <20220926153340.1621984-4-jolsa@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220926153340.1621984-1-jolsa@kernel.org> References: <20220926153340.1621984-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Using function address given at the generation time as the trampoline ip argument. This way we get directly the function address that we need, so we don't need to: - read the ip from the stack - subtract X86_PATCH_SIZE - subtract ENDBR_INSN_SIZE if CONFIG_X86_KERNEL_IBT is enabled which is not even implemented yet ;-) Signed-off-by: Jiri Olsa --- arch/x86/net/bpf_jit_comp.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index ae89f4143eb4..d4a6183197e9 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -662,7 +662,7 @@ static void emit_mov_imm64(u8 **pprog, u32 dst_reg, */ emit_mov_imm32(&prog, false, dst_reg, imm32_lo); } else { - /* movabsq %rax, imm64 */ + /* movabsq rax, imm64 */ EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); EMIT(imm32_lo, 4); EMIT(imm32_hi, 4); @@ -2039,13 +2039,14 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, 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, extra_nregs = 0; 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; @@ -2126,12 +2127,10 @@ 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 + * movabsq 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); } -- 2.37.3