From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F8212AB30 for ; Tue, 20 Jun 2023 17:11:20 +0000 (UTC) Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41AD410E2 for ; Tue, 20 Jun 2023 10:11:19 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id d9443c01a7336-1b53e1cd0ffso20011225ad.0 for ; Tue, 20 Jun 2023 10:11:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687281079; x=1689873079; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=vMCL9MBUgaXBCtQ1dLciPYdPyIFXYIps1O+bKc0deQ0=; b=c2NaxhmRSgTGmqtwGOgcvj17CEnylSGIv3WcFdpUb2eSNKfvAXIf5IUF1+mQuVOQyB BZtQiOT36t8kSMVYMAQow+OtzTbB5DHwAQePge6xo4TWNMJDcpDGSEx58wUFuOYeBScE cbdfvLI5uI6PoA8/caFs2LkU7IzA19uV5b57SKbt0w8JM3Sc/vcsdit1ZiGxHaz9QYhg +rINOnacoQWX4Lz/7/kmSIQWtjVeAhKh59yN9kNPfPun7IE2vNFcy7qYmSLvuJAeLVHd mEPuh+jL57kfzgEX/VjHrtuOux6aLqDKhybvbbB3VUfhNZQqDY+5bUq7OkItnGgmviUU UmpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687281079; x=1689873079; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=vMCL9MBUgaXBCtQ1dLciPYdPyIFXYIps1O+bKc0deQ0=; b=AKRljhZWtqzO+ivEnD8SEkbbQadnAUUzP4pu09JxcQoXt718wQO/sNgZR+gnEUlUpo 2yCkh7CT0nevQmyjRrGWtbbGYBMaLJ5qzuxCTUG/ve3FYS0vNXOgBn9F9s1e0INV45b6 CDgeQEfhYhzrC4YVxnbB1PaRMZC2kwUEOIyc93ec4ComaVVln9YPC05BIV+Gxzf+BZtk 5w1j6JqUIG6rOsZTR8UGKCsY+jZ5yLzluLILyKNk8lRcoy2mc0Evz0SvPgJ6Cnu1uvEW aCsJnIrdGx76f277SM/TD0R4Yop75tU1oy+u2GvJe99JaODDeXH4/I1waV4Szp9Cds4e p8Ug== X-Gm-Message-State: AC+VfDyt6mGOEQBdyBlhDmP7W5eaH1nVWG1HYQ1ARwB9xy03Bsh5Wkjy 1f6DOqjJmt2QhUncHnEV5wg= X-Google-Smtp-Source: ACHHUZ5RfcJeeo+Vn4GGoz3KLpbtyjmwvoRLXSAF+HdLHSrTN3Nth52WFit/tkU3h9DABhJMbrAQEA== X-Received: by 2002:a17:902:d2ca:b0:1ad:bb89:16f6 with SMTP id n10-20020a170902d2ca00b001adbb8916f6mr10096565plc.50.1687281078659; Tue, 20 Jun 2023 10:11:18 -0700 (PDT) Received: from MacBook-Pro-8.local ([2620:10d:c090:400::5:e719]) by smtp.gmail.com with ESMTPSA id i10-20020a17090332ca00b001b6758a2d94sm1835893plr.305.2023.06.20.10.11.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Jun 2023 10:11:18 -0700 (PDT) Date: Tue, 20 Jun 2023 10:11:15 -0700 From: Alexei Starovoitov To: Jiri Olsa Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo Subject: Re: [PATCHv2 bpf-next 01/24] bpf: Add multi uprobe link Message-ID: <20230620171115.ebel6f7kjeyy4msn@MacBook-Pro-8.local> References: <20230620083550.690426-1-jolsa@kernel.org> <20230620083550.690426-2-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230620083550.690426-2-jolsa@kernel.org> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Tue, Jun 20, 2023 at 10:35:27AM +0200, Jiri Olsa wrote: > +static int uprobe_prog_run(struct bpf_uprobe *uprobe, > + unsigned long entry_ip, > + struct pt_regs *regs) > +{ > + struct bpf_uprobe_multi_link *link = uprobe->link; > + struct bpf_uprobe_multi_run_ctx run_ctx = { > + .entry_ip = entry_ip, > + }; > + struct bpf_prog *prog = link->link.prog; > + struct bpf_run_ctx *old_run_ctx; > + int err = 0; > + > + might_fault(); > + > + rcu_read_lock_trace(); > + migrate_disable(); > + > + if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) > + goto out; bpf_prog_run_array_sleepable() doesn't do such things. Such 'proteciton' will actively hurt. The sleepable prog below will block all kprobes on this cpu. please remove. > + > + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); > + > + if (!prog->aux->sleepable) > + rcu_read_lock(); > + > + err = bpf_prog_run(link->link.prog, regs); > + > + if (!prog->aux->sleepable) > + rcu_read_unlock(); > + > + bpf_reset_run_ctx(old_run_ctx); > + > +out: > + __this_cpu_dec(bpf_prog_active); > + migrate_enable(); > + rcu_read_unlock_trace(); > + return err;