From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751911AbdBGBkx (ORCPT ); Mon, 6 Feb 2017 20:40:53 -0500 Received: from mail.kernel.org ([198.145.29.136]:40584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450AbdBGBkv (ORCPT ); Mon, 6 Feb 2017 20:40:51 -0500 Date: Tue, 7 Feb 2017 10:40:41 +0900 From: Masami Hiramatsu To: Ravi Bangoria Cc: acme@redhat.com, alexis.berlemont@gmail.com, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, mpe@ellerman.id.au, naveen.n.rao@linux.vnet.ibm.com, mhiramat@kernel.org, maddy@linux.vnet.ibm.com Subject: Re: [PATCH 5/5] perf/probe: Change MAX_CMDLEN Message-Id: <20170207104041.aebc2eb9ad4a6dd01f8a0f5c@kernel.org> In-Reply-To: <20170202111143.14319-6-ravi.bangoria@linux.vnet.ibm.com> References: <20161214000732.1710-1-alexis.berlemont@gmail.com> <20170202111143.14319-1-ravi.bangoria@linux.vnet.ibm.com> <20170202111143.14319-6-ravi.bangoria@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Feb 2017 16:41:43 +0530 Ravi Bangoria wrote: > There are many SDT markers in powerpc whose uprobe definition goes > beyond current MAX_CMDLEN, especially when target filename is long > and sdt marker has long list of arguments. For example, definition > of sdt marker > > method__compile__end: 8@17 8@9 8@10 -4@8 8@7 -4@6 8@5 -4@4 1@37(28) > > from file > > /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.91-2.b14.fc22.ppc64/jre/lib/\ > ppc64/server/libjvm.so > > is > > p:sdt_hotspot/method__compile__end /usr/lib/jvm/java-1.8.0-openjdk-\ > 1.8.0.91-2.b14.fc22.ppc64/jre/lib/ppc64/server/libjvm.so:0x4c4e00\ > arg1=%gpr17:u64 arg2=%gpr9:u64 arg3=%gpr10:u64 arg4=%gpr8:s32\ > arg5=%gpr7:u64 arg6=%gpr6:s32 arg7=%gpr5:u64 arg8=%gpr4:s32\ > arg9=+37(%gpr28):u8 > > Perf probe fails with seg fault for such markers. As uprobe_events file > accepts definition beyond 256 characters, increase value of MAX_CMDLEN > to 512. OK, actually in the kernel side, it accepts up to 4094 (+"\n\0") so it is a good time to expand it to 4094. (I found another buggy message in kernel... will be fixed soon) Thank you, > Signed-off-by: Ravi Bangoria > --- > tools/perf/util/probe-event.c | 1 - > tools/perf/util/probe-file.c | 2 +- > 2 files changed, 1 insertion(+), 2 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 2c1bca2..5f3256f 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -47,7 +47,6 @@ > #include "probe-file.h" > #include "session.h" > > -#define MAX_CMDLEN 256 > #define PERFPROBE_GROUP "probe" > > bool probe_event_dry_run; /* Dry run flag */ > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c > index 38eca3c..1580e26 100644 > --- a/tools/perf/util/probe-file.c > +++ b/tools/perf/util/probe-file.c > @@ -29,7 +29,7 @@ > #include "session.h" > #include "perf_regs.h" > > -#define MAX_CMDLEN 256 > +#define MAX_CMDLEN 512 > > static void print_open_warning(int err, bool uprobe) > { > -- > 2.9.3 > -- Masami Hiramatsu