Re: [PATCH RESEND] trace_uprobe: support reference counter in fd-based uprobe

From: Song Liu <songliubraving@fb.com>
To: kbuild test robot <lkp@intel.com>
Cc: "kbuild-all@01.org" <kbuild-all@01.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Kernel Team <Kernel-team@fb.com>,
	"Masami Hiramatsu" <mhiramat@kernel.org>,
	Oleg Nesterov <oleg@redhat.com>,
	"Srikar Dronamraju" <srikar@linux.vnet.ibm.com>,
	"Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH RESEND] trace_uprobe: support reference counter in fd-based uprobe
Date: Tue, 25 Sep 2018 14:46:32 +0000	[thread overview]
Message-ID: <2EAC58E5-A849-44AC-86E4-68C7D1AEB965@fb.com> (raw)
In-Reply-To: <201809251403.5GBHgN7F%fengguang.wu@intel.com>

Hi, 

This patch is based on this branch:

https://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git/log/?h=ftrace/core

Thanks,
Song

> On Sep 24, 2018, at 11:26 PM, kbuild test robot <lkp@intel.com> wrote:
> 
> Hi Song,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on tip/perf/core]
> [also build test ERROR on v4.19-rc5 next-20180925]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Song-Liu/trace_uprobe-support-reference-counter-in-fd-based-uprobe/20180925-135454
> config: i386-randconfig-x005-201838 (attached as .config)
> compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
> reproduce:
>        # save the attached .config to linux build tree
>        make ARCH=i386 
> 
> All errors (new ones prefixed by >>):
> 
>   kernel/trace/trace_uprobe.c: In function 'create_local_trace_uprobe':
>>> kernel/trace/trace_uprobe.c:1376:4: error: 'struct trace_uprobe' has no member named 'ref_ctr_offset'
>     tu->ref_ctr_offset = ref_ctr_offset;
>       ^~
> 
> vim +1376 kernel/trace/trace_uprobe.c
> 
>  1340	
>  1341	#ifdef CONFIG_PERF_EVENTS
>  1342	struct trace_event_call *
>  1343	create_local_trace_uprobe(char *name, unsigned long offs,
>  1344				  unsigned long ref_ctr_offset, bool is_return)
>  1345	{
>  1346		struct trace_uprobe *tu;
>  1347		struct path path;
>  1348		int ret;
>  1349	
>  1350		ret = kern_path(name, LOOKUP_FOLLOW, &path);
>  1351		if (ret)
>  1352			return ERR_PTR(ret);
>  1353	
>  1354		if (!d_is_reg(path.dentry)) {
>  1355			path_put(&path);
>  1356			return ERR_PTR(-EINVAL);
>  1357		}
>  1358	
>  1359		/*
>  1360		 * local trace_kprobes are not added to probe_list, so they are never
>  1361		 * searched in find_trace_kprobe(). Therefore, there is no concern of
>  1362		 * duplicated name "DUMMY_EVENT" here.
>  1363		 */
>  1364		tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
>  1365					is_return);
>  1366	
>  1367		if (IS_ERR(tu)) {
>  1368			pr_info("Failed to allocate trace_uprobe.(%d)\n",
>  1369				(int)PTR_ERR(tu));
>  1370			path_put(&path);
>  1371			return ERR_CAST(tu);
>  1372		}
>  1373	
>  1374		tu->offset = offs;
>  1375		tu->path = path;
>> 1376		tu->ref_ctr_offset = ref_ctr_offset;
>  1377		tu->filename = kstrdup(name, GFP_KERNEL);
>  1378		init_trace_event_call(tu, &tu->tp.call);
>  1379	
>  1380		if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
>  1381			ret = -ENOMEM;
>  1382			goto error;
>  1383		}
>  1384	
>  1385		return &tu->tp.call;
>  1386	error:
>  1387		free_trace_uprobe(tu);
>  1388		return ERR_PTR(ret);
>  1389	}
>  1390	
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
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> <.config.gz>