From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756864Ab0CCWDB (ORCPT ); Wed, 3 Mar 2010 17:03:01 -0500 Received: from mail-fx0-f219.google.com ([209.85.220.219]:62975 "EHLO mail-fx0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752346Ab0CCWCz (ORCPT ); Wed, 3 Mar 2010 17:02:55 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=Chz0r2+40HS+ZLdYhQQEOHmpTCdYYq0wZjrKWfJN2t15l5DdhD6oWGXY2N1FBgJM5/ JJtwABexDPbeVa0WurWw5nCb4ACmwd50XgHTApVhMEssuiMBSSypit8FH/VZzd+WfI1S +IJhxF4RUmTHzpvg45xFGldvOr0dRdoYT1SAQ= Date: Wed, 3 Mar 2010 23:02:52 +0100 From: Frederic Weisbecker To: Peter Zijlstra Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, paulus@samba.org, eranian@google.com, robert.richter@amd.com Subject: Re: [RFC][PATCH 07/11] perf: Provide PERF_SAMPLE_REGS Message-ID: <20100303220249.GF5194@nowhere> References: <20100303163936.906011640@chello.nl> <20100303164306.375353163@chello.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100303164306.375353163@chello.nl> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 03, 2010 at 05:39:43PM +0100, Peter Zijlstra wrote: > Simply copy out the provided pt_regs in a u64 aligned fashion. > > XXX: do task_pt_regs() and get_irq_regs() always clear everything or > are we now leaking data? It looks like there is a leak in case of non trace syscalls. where we don't appear to save r12-15. Then task_pt_regs() may leak the top of a process stack...? > > Signed-off-by: Peter Zijlstra > --- > include/linux/perf_event.h | 5 ++++- > kernel/perf_event.c | 17 +++++++++++++++++ > 2 files changed, 21 insertions(+), 1 deletion(-) > > Index: linux-2.6/include/linux/perf_event.h > =================================================================== > --- linux-2.6.orig/include/linux/perf_event.h > +++ linux-2.6/include/linux/perf_event.h > @@ -125,8 +125,9 @@ enum perf_event_sample_format { > PERF_SAMPLE_PERIOD = 1U << 8, > PERF_SAMPLE_STREAM_ID = 1U << 9, > PERF_SAMPLE_RAW = 1U << 10, > + PERF_SAMPLE_REGS = 1U << 11, > > - PERF_SAMPLE_MAX = 1U << 11, /* non-ABI */ > + PERF_SAMPLE_MAX = 1U << 12, /* non-ABI */ > }; > > /* > @@ -392,6 +393,7 @@ enum perf_event_type { > * { u64 period; } && PERF_SAMPLE_PERIOD > * > * { struct read_format values; } && PERF_SAMPLE_READ > + * { struct pt_regs regs; } && PERF_SAMPLE_REGS > * > * { u64 nr, > * u64 ips[nr]; } && PERF_SAMPLE_CALLCHAIN > @@ -800,6 +802,7 @@ struct perf_sample_data { > u64 period; > struct perf_callchain_entry *callchain; > struct perf_raw_record *raw; > + struct pt_regs *regs; > }; > > static inline > Index: linux-2.6/kernel/perf_event.c > =================================================================== > --- linux-2.6.orig/kernel/perf_event.c > +++ linux-2.6/kernel/perf_event.c > @@ -3176,6 +3176,17 @@ void perf_output_sample(struct perf_outp > if (sample_type & PERF_SAMPLE_READ) > perf_output_read(handle, event); > > + if (sample_type & PERF_SAMPLE_REGS) { > + int size = DIV_ROUND_UP(sizeof(struct pt_regs), sizeof(u64)) - > + sizeof(struct pt_regs); > + > + perf_output_put(handle, *data->regs); > + if (size) { > + u64 zero = 0; > + perf_output_copy(handle, &zero, size); > + } > + } > + > if (sample_type & PERF_SAMPLE_CALLCHAIN) { > if (data->callchain) { > int size = 1; > @@ -3273,6 +3284,12 @@ void perf_prepare_sample(struct perf_eve > if (sample_type & PERF_SAMPLE_READ) > header->size += perf_event_read_size(event); > > + if (sample_type & PERF_SAMPLE_REGS) { > + data->regs = regs; > + header->size += DIV_ROUND_UP(sizeof(struct pt_regs), > + sizeof(u64)); > + } > + > if (sample_type & PERF_SAMPLE_CALLCHAIN) { > int size = 1; > > > -- >