From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Budankov Subject: [PATCH v5 03/10] perf/core: open access to anon probes for CAP_PERFMON privileged process Date: Mon, 20 Jan 2020 14:26:04 +0300 Message-ID: <750f7e60-3b7c-f2e7-fd33-bddbfea5ff57@linux.intel.com> References: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "jani.nikula@linux.intel.com" , "joonas.lahtinen@linux.intel.com" , "rodrigo.vivi@intel.com" , "benh@kernel.crashing.org" , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , James Morris , Will Deacon , Mark Rutland , Robert Richter , Alexei Starovoitov Cc: Jiri Olsa , Andi Kleen , Stephane Eranian , Igor Lubashev , Alexander Shishkin , Namhyung Kim , Song Liu , Lionel Landwerlin , Thomas Gleixner , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "linux-parisc@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , linux-arm-kernel@lists.infradead.org List-Id: linux-perf-users.vger.kernel.org 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 --- 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