From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752729AbbDHDuZ (ORCPT ); Tue, 7 Apr 2015 23:50:25 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:57294 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750943AbbDHDuY (ORCPT ); Tue, 7 Apr 2015 23:50:24 -0400 Message-ID: <5524A55B.4050707@huawei.com> Date: Wed, 8 Apr 2015 11:49:47 +0800 From: Wang Nan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo CC: , , , , , Subject: Re: [PATCH v3 2/2] perf: report/annotate: fix segfault problem. References: <20150406125239.GE2500@redhat.com> <1428394966-131044-1-git-send-email-wangnan0@huawei.com> <1428394966-131044-3-git-send-email-wangnan0@huawei.com> <20150407151322.GK11983@kernel.org> In-Reply-To: <20150407151322.GK11983@kernel.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.69.129] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/4/7 23:13, Arnaldo Carvalho de Melo wrote: > Em Tue, Apr 07, 2015 at 08:22:46AM +0000, Wang Nan escreveu: >> perf report and perf annotate are easy to trigger segfault if trace data >> contain kernel module information like this: >> >> # perf report -D -i ./perf.data >> ... >> 0 0 0x188 [0x50]: PERF_RECORD_MMAP -1/0: [0xffffffbff1018000(0xf068000) @ 0]: x [test_module] >> ... >> >> # perf report -i ./perf.data --objdump=/path/to/objdump --kallsyms=/path/to/kallsyms >> >> perf: Segmentation fault >> -------- backtrace -------- >> /path/to/perf[0x503478] >> /lib64/libc.so.6(+0x3545f)[0x7fb201f3745f] >> /path/to/perf[0x499b56] > > So, with this patch applied I am seeing this: > > [root@ssdandy ~]# perf sched record -a > Kmod (modules.order) and cpumode (0) inconsistent > Kmod (modules.builtin) and cpumode (0) inconsistent > Kmod (modules.dep) and cpumode (0) inconsistent > Kmod (modules.dep.bin) and cpumode (0) inconsistent > Kmod (modules.alias) and cpumode (0) inconsistent > Kmod (modules.alias.bin) and cpumode (0) inconsistent > Kmod (modules.softdep) and cpumode (0) inconsistent > Kmod (modules.symbols) and cpumode (0) inconsistent > Kmod (modules.symbols.bin) and cpumode (0) inconsistent > Kmod (modules.builtin.bin) and cpumode (0) inconsistent > Kmod (modules.devname) and cpumode (0) inconsistent > ^C[ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.465 MB perf.data (1595 samples) ] > > [root@ssdandy ~]#o > > Can you please check this? > > Why do we get these warning for these files? > This is because in map_groups__set_modules_path_dir() we enumerate over each file in /lib/modules/`uname -a`/ and use kmod_path__parse_name() to parse their names. In this v3 patch, I update __kmod_path__parse() to check consistency between m.kmod and cpumode. It will warn if one passes a kernel module name with user space cpumode, or passes kernel space cpumode with a non-kmodule name. I'll post a patch v4 to avoid such warning if passed cpumode is not explicitly set to user or kernel. Difference from v3: diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index fb1ed7d..875f7c9 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -215,7 +215,7 @@ int __kmod_path__parse(struct kmod_path *m, const char *path, const char *name = strrchr(path, '/'); const char *ext = strrchr(path, '.'); bool is_simple_name = false; - bool cpu_mode_kernel, is_kernel = false; + bool cpu_mode_kernel, cpu_mode_unknown = false, is_kernel = false; /* treat PERF_RECORD_MISC_CPUMODE_UNKNOWN as kernel. */ switch (cpumode & PERF_RECORD_MISC_CPUMODE_MASK) { @@ -224,6 +224,9 @@ int __kmod_path__parse(struct kmod_path *m, const char *path, case PERF_RECORD_MISC_GUEST_USER: cpu_mode_kernel = false; break; + case PERF_RECORD_MISC_CPUMODE_UNKNOWN: + cpu_mode_unknown = true; + /* fall through */ default: cpu_mode_kernel = true; } @@ -288,10 +291,12 @@ int __kmod_path__parse(struct kmod_path *m, const char *path, } } out: - if ((m->kmod && !cpu_mode_kernel) || - (cpu_mode_kernel && !m->kmod && !is_kernel)) - pr_warning("Kmod (%s) and cpumode (%d) inconsistent\n", - path, cpumode); + if (!cpu_mode_unknown) { + if ((m->kmod && !cpu_mode_kernel) || + (cpu_mode_kernel && !m->kmod && !is_kernel)) + pr_warning("Kmod (%s) and cpumode (%d) inconsistent\n", + path, cpumode); + } return 0; } > > Applied the other patch: > > -> 28 T 04/07 Wang Nan (8,8K) [PATCH v3 1/2] perf: kmaps: enforce usage of kmaps to protect futher bugs. > > > - Arnaldo >