Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: [PATCH v5 03/10] perf/core: open access to anon probes for
 CAP_PERFMON privileged process
From:   Alexey Budankov <alexey.budankov@linux.intel.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        "jani.nikula@linux.intel.com" <jani.nikula@linux.intel.com>,
        "joonas.lahtinen@linux.intel.com" <joonas.lahtinen@linux.intel.com>,
        "rodrigo.vivi@intel.com" <rodrigo.vivi@intel.com>,
        "benh@kernel.crashing.org" <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        "james.bottomley@hansenpartnership.com" 
        <james.bottomley@hansenpartnership.com>,
        Serge Hallyn <serge@hallyn.com>,
        James Morris <jmorris@namei.org>,
        Will Deacon <will.deacon@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Robert Richter <rric@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>
Cc:     Jiri Olsa <jolsa@redhat.com>, Andi Kleen <ak@linux.intel.com>,
        Stephane Eranian <eranian@google.com>,
        Igor Lubashev <ilubashe@akamai.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Song Liu <songliubraving@fb.com>,
        Lionel Landwerlin <lionel.g.landwerlin@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        "linux-security-module@vger.kernel.org" 
        <linux-security-module@vger.kernel.org>,
        "selinux@vger.kernel.org" <selinux@vger.kernel.org>,
        "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>,
        "linux-parisc@vger.kernel.org" <linux-parisc@vger.kernel.org>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        linux-arm-kernel@lists.infradead.org,
        "linux-perf-users@vger.kernel.org" <linux-perf-users@vger.kernel.org>,
        oprofile-list@lists.sf.net
References: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com>
Organization: Intel Corp.
Message-ID: <750f7e60-3b7c-f2e7-fd33-bddbfea5ff57@linux.intel.com>
Date:   Mon, 20 Jan 2020 14:26:04 +0300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101
 Thunderbird/68.4.1
MIME-Version: 1.0
In-Reply-To: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


Open access to anon kprobes, uprobes and eBPF tracing for CAP_PERFMON
privileged processes. For backward compatibility reasons access remains
open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure monitoring is discouraged with respect to CAP_PERFMON capability.
Providing the access under CAP_PERFMON capability singly, without the
rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the
credentials and makes operations more secure.

Anon kprobes and uprobes are used by ftrace and eBPF. perf probe uses
ftrace to define new kprobe events, and those events are treated as
tracepoint events. eBPF defines new probes via perf_event_open syscall
and then the probes are used in eBPF tracing.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 kernel/events/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index b1fcbbe24849..8a6c0b08451d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9088,7 +9088,7 @@ static int perf_kprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_kprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
@@ -9148,7 +9148,7 @@ static int perf_uprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_uprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
-- 
2.20.1