From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELssCylrQ/Lgh8Svvfa1bTpfm5a7R3rqetTdnM0gkbqxbe4zcmijP6dSe3c9DFlUhBQf5rZe ARC-Seal: i=1; a=rsa-sha256; t=1521132501; cv=none; d=google.com; s=arc-20160816; b=qIDbHiM94JXcY+Bz2AXOfrlKABKBEUI+YWyhIc6UbEZorOrtQv9gqMS4//wbm3wVEj dZLKD4BtiIP65HWg8x+yNEpVOOUUEZJTQ5Tai60HUFnuoQdRfC6fbNAMJYnNQAQ77yfo 47SFH8jmX11jAug2roVwXvKZ6zxxc4TKBscMVbaVFLxzkbWATRS3F17rEDnrLKR6zGeX c4BektnPVKakcJJjRFNKpFkZ/kzJqs3cDU/oCxD6DchRpdMJ06Rndaxin5nk0hMP1afG 8VEbYn9IdG5fm/347y2xrQpbQxHQr/Ze5B5dAjzN+OEG+ngwQs7xX/yTSvfAkelp/HFE UArw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:dmarc-filter :arc-authentication-results; bh=PLGYm2vh8lfmGqTtajBRs06y4nL9ptVFBAhhb5iecU0=; b=ZHenMREnrX3iTYmikQ3cbmyzbzCLDu8dTxSljr2uXg89bPPnnIJ/IVjV4J+OGWiYus BJhoL6snial2LueKaZkYlCldjIzzEvrXiRSFxsM7YhsnLic7UeL2VVzA6Ayk5niPJbxy /B0LIihiHKMd66yelMI7iq3Hqp2FAoufP5YHnIH0SKss0F/PTJ6gxWVRaqpnzzLuq/Xt r8TTz9CkfUwo6YqZCpwM+stbQ8Hft/fDuJFCrIbVSaSn65JIQKYpY8Ff9nxwT3ECoiuj bkj9lVOpMVjY4fq7bzfHT5bM2J+wXLJOlYmUNYB0w1rQhZXtZmjBHkZtUieoSoN2l0lS H5tg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=ddtq=gf=goodmis.org=rostedt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ddTQ=GF=goodmis.org=rostedt@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=ddtq=gf=goodmis.org=rostedt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ddTQ=GF=goodmis.org=rostedt@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49C9420779 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Thu, 15 Mar 2018 12:48:16 -0400 From: Steven Rostedt To: Ravi Bangoria Cc: mhiramat@kernel.org, oleg@redhat.com, peterz@infradead.org, srikar@linux.vnet.ibm.com, acme@kernel.org, ananth@linux.vnet.ibm.com, akpm@linux-foundation.org, alexander.shishkin@linux.intel.com, alexis.berlemont@gmail.com, corbet@lwn.net, dan.j.williams@intel.com, gregkh@linuxfoundation.org, huawei.libin@huawei.com, hughd@google.com, jack@suse.cz, jglisse@redhat.com, jolsa@redhat.com, kan.liang@intel.com, kirill.shutemov@linux.intel.com, kjlx@templeofstupid.com, kstewart@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, milian.wolff@kdab.com, mingo@redhat.com, namhyung@kernel.org, naveen.n.rao@linux.vnet.ibm.com, pc@us.ibm.com, pombredanne@nexb.com, tglx@linutronix.de, tmricht@linux.vnet.ibm.com, willy@infradead.org, yao.jin@linux.intel.com, fengguang.wu@intel.com Subject: Re: [PATCH 5/8] trace_uprobe: Support SDT markers having reference count (semaphore) Message-ID: <20180315124816.6aa3d4e2@vmware.local.home> In-Reply-To: <20180313125603.19819-6-ravi.bangoria@linux.vnet.ibm.com> References: <20180313125603.19819-1-ravi.bangoria@linux.vnet.ibm.com> <20180313125603.19819-6-ravi.bangoria@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594827101403620100?= X-GMAIL-MSGID: =?utf-8?q?1595023033727215189?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, 13 Mar 2018 18:26:00 +0530 Ravi Bangoria wrote: > +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) > +{ > + struct uprobe_map_info *info; > + struct vm_area_struct *vma; > + unsigned long vaddr; > + > + uprobe_start_dup_mmap(); Please add a comment here that this function ups the mm ref count for each info returned. Otherwise it's hard to know what that mmput() below matches. -- Steve > + info = uprobe_build_map_info(tu->inode->i_mapping, > + tu->ref_ctr_offset, false); > + if (IS_ERR(info)) > + goto out; > + > + while (info) { > + down_write(&info->mm->mmap_sem); > + > + vma = sdt_find_vma(info->mm, tu); > + vaddr = vma_offset_to_vaddr(vma, tu->ref_ctr_offset); > + sdt_update_ref_ctr(info->mm, vaddr, 1); > + > + up_write(&info->mm->mmap_sem); > + mmput(info->mm); > + info = uprobe_free_map_info(info); > + } > + > +out: > + uprobe_end_dup_mmap(); > +} > +