From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsu/w+FCzCLpX/HMqnRk64WsDtRgc3B75mKRsaeusuVSUrtQo2JBQM0dxMEbYFKAmup5bsG ARC-Seal: i=1; a=rsa-sha256; t=1520945751; cv=none; d=google.com; s=arc-20160816; b=TLdx6xrns5KM0/uDz0TMGNFJqrWWyDvwqN+MAfSDSKPQV1W7qT6o4djAzg5B+KkpT5 kMmpIVdToLlm7IKbhscOLjo0hToR8tdNr2etESvLvpCqonmdbO8+MILJ47MBIEIs4Tv0 iW38Kt2xCB6exHijmxRiq6/rtTDku5WkCBROjDC/NOopLtit5wTlP+M3mBZMITd1G9vV +jw4RqApxYLXeQhoVkUu6rte5t/ygkCL0VUBN2zeMD2maLLG0Eh4LgGs4APu2HY+Dkm/ yv/VHfskGKb8qd4Gx2X7XTcFwD4MYdmT8sfFgxUDNIjndHzthz12Qno9/93aXhgCBVYq nQ4Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:references:in-reply-to:date:subject:cc:to:from :arc-authentication-results; bh=0uryX3yqfID8k/gJvxPL1S1vocT4sejXhk351X/JsFQ=; b=xre10Dp26JXZbAGGLFGDKRcST3hoYa8mgfkAP/StwgU6B6xdL20JnlnlEfS8Kc/h/r gSf0xBsmlewdG3ZmyIcmfBtbhryvGKUXJPb1r66LHb9KYv4qKEVv/2xipKDX9uNpZSLC iAmwJaBIebeAjg4F7x0Lu43Ik6K55WI+PLVzMm3glS9zr9QwEQcBT3kpH76HUUlRLJlA Wl9lEZJgJ1jOVc9cx4LMdooMh4XkAHaiZlz+kCUNdtHoGbBpNW2IwSLg7qlxyERqLl49 zlhvf6WxyvPduMPHuP89e+dPMxPLAMiuoRZDPsBxmeVHJEVOwF34aviKCs1ROAY7q5Io xq+w== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 148.163.158.5 is neither permitted nor denied by best guess record for domain of ravi.bangoria@linux.vnet.ibm.com) smtp.mailfrom=ravi.bangoria@linux.vnet.ibm.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=ibm.com Authentication-Results: mx.google.com; spf=neutral (google.com: 148.163.158.5 is neither permitted nor denied by best guess record for domain of ravi.bangoria@linux.vnet.ibm.com) smtp.mailfrom=ravi.bangoria@linux.vnet.ibm.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=ibm.com From: Ravi Bangoria To: mhiramat@kernel.org, oleg@redhat.com, peterz@infradead.org, srikar@linux.vnet.ibm.com Cc: 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, rostedt@goodmis.org, tglx@linutronix.de, tmricht@linux.vnet.ibm.com, willy@infradead.org, yao.jin@linux.intel.com, fengguang.wu@intel.com, Ravi Bangoria Subject: [PATCH 8/8] trace_uprobe/sdt: Document about reference counter Date: Tue, 13 Mar 2018 18:26:03 +0530 X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180313125603.19819-1-ravi.bangoria@linux.vnet.ibm.com> References: <20180313125603.19819-1-ravi.bangoria@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18031312-0040-0000-0000-0000041F00AA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18031312-0041-0000-0000-000026222B91 Message-Id: <20180313125603.19819-9-ravi.bangoria@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-13_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803130154 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594827212550255650?= X-GMAIL-MSGID: =?utf-8?q?1594827212550255650?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: No functionality changes. Signed-off-by: Ravi Bangoria --- Documentation/trace/uprobetracer.txt | 16 +++++++++++++--- kernel/trace/trace.c | 2 +- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt index bf526a7c..8fb13b0 100644 --- a/Documentation/trace/uprobetracer.txt +++ b/Documentation/trace/uprobetracer.txt @@ -19,15 +19,25 @@ user to calculate the offset of the probepoint in the object. Synopsis of uprobe_tracer ------------------------- - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) - -:[GRP/]EVENT : Clear uprobe or uretprobe event + p[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + r[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + -:[GRP/]EVENT + + p : Set a uprobe + r : Set a return uprobe (uretprobe) + - : Clear uprobe or uretprobe event GRP : Group name. If omitted, "uprobes" is the default value. EVENT : Event name. If omitted, the event name is generated based on PATH+OFFSET. PATH : Path to an executable or a library. OFFSET : Offset where the probe is inserted. + REF_CTR_OFFSET: Reference counter offset. Optional field. Reference count + gate the invocation of probe. If present, by default + reference count is 0. Kernel needs to increment it before + tracing the probe and decrement it when done. This is + identical to semaphore in Userspace Statically Defined + Tracepoints (USDT). FETCHARGS : Arguments. Each probe can have up to 128 args. %REG : Fetch register REG diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20a2300..2104d03 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4604,7 +4604,7 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file) "place (kretprobe): [:][+]|\n" #endif #ifdef CONFIG_UPROBE_EVENTS - "\t place: :\n" + " place (uprobe): :[(ref_ctr_offset)]\n" #endif "\t args: =fetcharg[:type]\n" "\t fetcharg: %, @
, @[+|-],\n" -- 1.8.3.1