Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756395AbdCUFT6 (ORCPT ); Tue, 21 Mar 2017 01:19:58 -0400 Received: from mail.kernel.org ([198.145.29.136]:53984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751675AbdCUFT4 (ORCPT ); Tue, 21 Mar 2017 01:19:56 -0400 Date: Tue, 21 Mar 2017 14:19:50 +0900 From: Masami Hiramatsu To: Ravi Bangoria Cc: acme@redhat.com, linux-kernel@vger.kernel.org, alexis.berlemont@gmail.com, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, mpe@ellerman.id.au, naveen.n.rao@linux.vnet.ibm.com, maddy@linux.vnet.ibm.com Subject: Re: [PATCH v2] perf/probe: Change MAX_CMDLEN Message-Id: <20170321141950.3dbd5ba41f660450ea9e0d71@kernel.org> In-Reply-To: <20170207054547.3690-1-ravi.bangoria@linux.vnet.ibm.com> References: <20170207104041.aebc2eb9ad4a6dd01f8a0f5c@kernel.org> <20170207054547.3690-1-ravi.bangoria@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-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 Content-Length: 2204 Lines: 76 On Tue, 7 Feb 2017 11:15:47 +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 upto 4094 characters(4096 - 2 (\n\0)), increase value > of MAX_CMDLEN to 4094. This looks good to me. Acked-by: Masami Hiramatsu Thanks, > > Signed-off-by: Ravi Bangoria > --- > Changes in v2: > - Set MAX_CMDLEN to 4094 instead of 512 > > tools/perf/util/probe-event.c | 1 - > tools/perf/util/probe-file.c | 3 ++- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 6a6f44d..e6e3244 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..fdabe7e 100644 > --- a/tools/perf/util/probe-file.c > +++ b/tools/perf/util/probe-file.c > @@ -29,7 +29,8 @@ > #include "session.h" > #include "perf_regs.h" > > -#define MAX_CMDLEN 256 > +/* 4096 - 2 ('\n' + '\0') */ > +#define MAX_CMDLEN 4094 > > static void print_open_warning(int err, bool uprobe) > { > -- > 2.9.3 > -- Masami Hiramatsu