From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B074C433DF for ; Tue, 9 Jun 2020 15:13:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBE8207C3 for ; Tue, 9 Jun 2020 15:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591715631; bh=Hz3L8+5ifhOMGNZlsBtp86xHQWd1bggYuz2oDBEhF8k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Ya7wH71rTF+dcLtHDKKjUdFP0iIeqQ6nzeLr/yDR5oZ/D4mrdzrG3dKwG0oJXK6Oz XmTT95c10WfbOuV0pWFF6KmFeLRBZYc84Gu5HgJetsuFrmtWr8uuOfOrYpinKa01sf ClehXhajmUxfrhXpiP5zdGUyOu5MZsM3c1hwCNAY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730767AbgFIPNt (ORCPT ); Tue, 9 Jun 2020 11:13:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:51434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730673AbgFIPNs (ORCPT ); Tue, 9 Jun 2020 11:13:48 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 677EE20734; Tue, 9 Jun 2020 15:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591715627; bh=Hz3L8+5ifhOMGNZlsBtp86xHQWd1bggYuz2oDBEhF8k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m28NIcISxyHiFWgd1jg3MrYOc+Hyx5Bd+OamH2cMzBvS/QQjyIErVpNVHreaQpy1T ijC9siPL7WmL2cI7NDs0GNTfdG4G6qrYavF4jT7YeumX9VRL+Y4pJ2B8Lte9cKyix0 pRZx1hj8NgAyYgD2AqfqhZua01yRtmeCKIM2nDUk= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id B909B40AFD; Tue, 9 Jun 2020 12:13:44 -0300 (-03) Date: Tue, 9 Jun 2020 12:13:44 -0300 From: Arnaldo Carvalho de Melo To: Sumanth Korikkar Cc: Steven Rostedt , linux-perf-users@vger.kernel.org, bpf@vger.kernel.org, jolsa@redhat.com, tmricht@linux.ibm.com, heiko.carstens@de.ibm.com, mhiramat@kernel.org, iii@linux.ibm.com, Linux Kernel Mailing List Subject: Re: [PATCH v2 1/2] perf: Fix user attribute access in kprobes Message-ID: <20200609151344.GD24868@kernel.org> References: <20200609081019.60234-1-sumanthk@linux.ibm.com> <20200609081019.60234-2-sumanthk@linux.ibm.com> <20200609150931.GC24868@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200609150931.GC24868@kernel.org> X-Url: http://acmel.wordpress.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Jun 09, 2020 at 12:09:31PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Jun 09, 2020 at 10:10:18AM +0200, Sumanth Korikkar escreveu: > > Issue: > > perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user' did not work before. > > > > Fix: > > Make (perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user') output equivalent to ftrace > > ('p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32 > > sched_priority=+u0(%r4):s32' > kprobe_events) > > > > Other: > > 1. Right now, __match_glob() does not handle [u]. For now, use > > *u]. > > 2. @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: > > Add user memory access attribute support") > > > > Test: > > 1. perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user' > > > > 2 ./perf script > > sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) > > pid=261614 policy=2 sched_priority=1 > > > > 3. cat /sys/kernel/debug/tracing/trace > > <...>-309956 [006] .... 1616098.093957: 0: prio: 1 > > Thanks, I'm adding this: > > Fixes: 1e032f7cfa14 ("perf-probe: Add user memory access attribute support") > Cc: Masami Hiramatsu > Cc: Steven Rostedt (VMware) > > So that the stable guys pick this up eventually, > > That first hunk with the strcmp() return check could have gone into a > separate patch, but I'll process it as-is for expediency, I also added this: ommitter testing: Before: # perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' param(type:sched_param) has no member sched_priority@user. Error: Failed to add events. # pahole sched_param struct sched_param { int sched_priority; /* 0 4 */ /* size: 4, cachelines: 1, members: 1 */ /* last cacheline: 4 bytes */ }; # After: # perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' Added new event: probe:do_sched_setscheduler (on do_sched_setscheduler with pid policy sched_priority=param->sched_priority) You can now use it in all perf tools, such as: perf record -e probe:do_sched_setscheduler -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_sched_setscheduler _text+1113792 pid=%di:s32 policy=%si:s32 sched_priority=+u0(%dx):s32 # > - Arnaldo > > > Signed-off-by: Sumanth Korikkar > > Reviewed-by: Thomas Richter > > Acked-by: Masami Hiramatsu > > --- > > tools/perf/util/probe-event.c | 7 +++++-- > > tools/perf/util/probe-file.c | 2 +- > > 2 files changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > > index a08f373d3305..df713a5d1e26 100644 > > --- a/tools/perf/util/probe-event.c > > +++ b/tools/perf/util/probe-event.c > > @@ -1575,7 +1575,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) > > } > > > > tmp = strchr(str, '@'); > > - if (tmp && tmp != str && strcmp(tmp + 1, "user")) { /* user attr */ > > + if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */ > > if (!user_access_is_supported()) { > > semantic_error("ftrace does not support user access\n"); > > return -EINVAL; > > @@ -1995,7 +1995,10 @@ static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref, > > if (depth < 0) > > return depth; > > } > > - err = strbuf_addf(buf, "%+ld(", ref->offset); > > + if (ref->user_access) > > + err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset); > > + else > > + err = strbuf_addf(buf, "%+ld(", ref->offset); > > return (err < 0) ? err : depth; > > } > > > > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c > > index 8c852948513e..064b63a6a3f3 100644 > > --- a/tools/perf/util/probe-file.c > > +++ b/tools/perf/util/probe-file.c > > @@ -1044,7 +1044,7 @@ static struct { > > DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), > > DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), > > DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"), > > - DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]*"), > > + DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]*"), > > DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"), > > DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"), > > }; > > -- > > 2.17.1 > > > > -- > > - Arnaldo -- - Arnaldo