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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA101C6778A for ; Tue, 3 Jul 2018 17:25:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DA1622565 for ; Tue, 3 Jul 2018 17:25:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DA1622565 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934347AbeGCRZt (ORCPT ); Tue, 3 Jul 2018 13:25:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37514 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933637AbeGCRZr (ORCPT ); Tue, 3 Jul 2018 13:25:47 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 15C8081ACF31; Tue, 3 Jul 2018 17:25:47 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.34.27.30]) by smtp.corp.redhat.com (Postfix) with SMTP id 2981C178B1; Tue, 3 Jul 2018 17:25:44 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 3 Jul 2018 19:25:46 +0200 (CEST) Date: Tue, 3 Jul 2018 19:25:43 +0200 From: Oleg Nesterov To: Ravi Bangoria Cc: srikar@linux.vnet.ibm.com, rostedt@goodmis.org, mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, linux-doc@vger.kernel.org, ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com, naveen.n.rao@linux.vnet.ibm.com, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com Subject: Re: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) Message-ID: <20180703172543.GC23144@redhat.com> References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> <20180701210935.GA14404@redhat.com> <0c543791-f3b7-5a4b-f002-e1c76bb430c0@linux.ibm.com> <20180702180156.GA31400@redhat.com> <20180703163645.GA23144@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180703163645.GA23144@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 03 Jul 2018 17:25:47 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 03 Jul 2018 17:25:47 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'oleg@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/03, Oleg Nesterov wrote: > > In short. There is a 1:1 relationship between uprobe_write_opcode(is_register => 1) > and install_breakpoint(), and between uprobe_write_opcode(is_register => 0) and > remove_breakpoint(). Whatever uprobe_write_opcode() can do if is_register == 1 can be > done in install_breakpoint(), the same for is_register == 0 and remove_breakpont(). > > What have I missed? Ah. I missed the fact that uprobe_write_opcode() doesn't do update_ref_ctr() if verify_opcode() returns false. Now I understand what did you mean by "for each consumer". So if we move this logic into install/remove_breakpoint as I tried to suggest, we will also need another error code for the case when verify_opcode() returns false. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 9CCD27DE6E for ; Tue, 3 Jul 2018 17:26:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934320AbeGCRZs (ORCPT ); Tue, 3 Jul 2018 13:25:48 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37514 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933637AbeGCRZr (ORCPT ); Tue, 3 Jul 2018 13:25:47 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 15C8081ACF31; Tue, 3 Jul 2018 17:25:47 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.34.27.30]) by smtp.corp.redhat.com (Postfix) with SMTP id 2981C178B1; Tue, 3 Jul 2018 17:25:44 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 3 Jul 2018 19:25:46 +0200 (CEST) Date: Tue, 3 Jul 2018 19:25:43 +0200 From: Oleg Nesterov To: Ravi Bangoria Cc: srikar@linux.vnet.ibm.com, rostedt@goodmis.org, mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, corbet@lwn.net, linux-doc@vger.kernel.org, ananth@linux.vnet.ibm.com, alexis.berlemont@gmail.com, naveen.n.rao@linux.vnet.ibm.com, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com Subject: Re: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) Message-ID: <20180703172543.GC23144@redhat.com> References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> <20180701210935.GA14404@redhat.com> <0c543791-f3b7-5a4b-f002-e1c76bb430c0@linux.ibm.com> <20180702180156.GA31400@redhat.com> <20180703163645.GA23144@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180703163645.GA23144@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 03 Jul 2018 17:25:47 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 03 Jul 2018 17:25:47 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'oleg@redhat.com' RCPT:'' Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 07/03, Oleg Nesterov wrote: > > In short. There is a 1:1 relationship between uprobe_write_opcode(is_register => 1) > and install_breakpoint(), and between uprobe_write_opcode(is_register => 0) and > remove_breakpoint(). Whatever uprobe_write_opcode() can do if is_register == 1 can be > done in install_breakpoint(), the same for is_register == 0 and remove_breakpont(). > > What have I missed? Ah. I missed the fact that uprobe_write_opcode() doesn't do update_ref_ctr() if verify_opcode() returns false. Now I understand what did you mean by "for each consumer". So if we move this logic into install/remove_breakpoint as I tried to suggest, we will also need another error code for the case when verify_opcode() returns false. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: oleg@redhat.com (Oleg Nesterov) Date: Tue, 3 Jul 2018 19:25:43 +0200 Subject: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore) In-Reply-To: <20180703163645.GA23144@redhat.com> References: <20180628052209.13056-1-ravi.bangoria@linux.ibm.com> <20180628052209.13056-7-ravi.bangoria@linux.ibm.com> <20180701210935.GA14404@redhat.com> <0c543791-f3b7-5a4b-f002-e1c76bb430c0@linux.ibm.com> <20180702180156.GA31400@redhat.com> <20180703163645.GA23144@redhat.com> Message-ID: <20180703172543.GC23144@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/03, Oleg Nesterov wrote: > > In short. There is a 1:1 relationship between uprobe_write_opcode(is_register => 1) > and install_breakpoint(), and between uprobe_write_opcode(is_register => 0) and > remove_breakpoint(). Whatever uprobe_write_opcode() can do if is_register == 1 can be > done in install_breakpoint(), the same for is_register == 0 and remove_breakpont(). > > What have I missed? Ah. I missed the fact that uprobe_write_opcode() doesn't do update_ref_ctr() if verify_opcode() returns false. Now I understand what did you mean by "for each consumer". So if we move this logic into install/remove_breakpoint as I tried to suggest, we will also need another error code for the case when verify_opcode() returns false. Oleg.