From: tip-bot for Igor Lubashev <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: alexander.shishkin@linux.intel.com, tglx@linutronix.de,
hpa@zytor.com, jolsa@kernel.org, mathieu.poirier@linaro.org,
linux-kernel@vger.kernel.org, peterz@infradead.org,
alexey.budankov@linux.intel.com, jmorris@namei.org,
mingo@kernel.org, namhyung@kernel.org, ilubashe@akamai.com,
suzuki.poulose@arm.com, acme@redhat.com
Subject: [tip:perf/core] perf tools: Add helpers to use capabilities if present
Date: Thu, 15 Aug 2019 02:25:27 -0700 [thread overview]
Message-ID: <tip-c22e150e3afa6f8db2300bd510e4ac26bbee1bf3@git.kernel.org> (raw)
In-Reply-To: <8a1e76cf5c7c9796d0d4d240fbaa85305298aafa.1565188228.git.ilubashe@akamai.com>
Commit-ID: c22e150e3afa6f8db2300bd510e4ac26bbee1bf3
Gitweb: https://git.kernel.org/tip/c22e150e3afa6f8db2300bd510e4ac26bbee1bf3
Author: Igor Lubashev <ilubashe@akamai.com>
AuthorDate: Wed, 7 Aug 2019 10:44:14 -0400
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 14 Aug 2019 10:48:39 -0300
perf tools: Add helpers to use capabilities if present
Add utilities to help checking capabilities of the running procss. Make
perf link with libcap, if it is available. If no libcap-dev[el],
fallback to the geteuid() == 0 test used before.
Committer notes:
$ perf test python
18: 'import perf' in python : FAILED!
$ perf test -v python
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
18: 'import perf' in python :
--- start ---
test child forked, pid 23288
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: cap_get_flag
test child finished with -1
---- end ----
'import perf' in python: FAILED!
$
This happens because differently from the perf binary generated with
this patch applied:
$ ldd /tmp/build/perf/perf | grep libcap
libcap.so.2 => /lib64/libcap.so.2 (0x00007f724a4ef000)
$
The python binding isn't linking with libcap:
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$
So add 'cap' to the 'extra_libraries' variable in
tools/perf/util/setup.py, and rebuild:
$ perf test python
18: 'import perf' in python : Ok
$
If we explicitely disable libcap it also continues to work:
$ make NO_LIBCAP=1 -C tools/perf O=/tmp/build/perf install-bin
$ ldd /tmp/build/perf/perf | grep libcap
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$ perf test python
18: 'import perf' in python : Ok
$
Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
[ split from a larger patch ]
Link: http://lkml.kernel.org/r/8a1e76cf5c7c9796d0d4d240fbaa85305298aafa.1565188228.git.ilubashe@akamai.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/Build | 2 ++
tools/perf/util/cap.c | 29 +++++++++++++++++++++++++++++
tools/perf/util/cap.h | 27 +++++++++++++++++++++++++++
tools/perf/util/event.h | 1 +
tools/perf/util/python-ext-sources | 1 +
tools/perf/util/setup.py | 2 ++
tools/perf/util/util.c | 9 +++++++++
7 files changed, 71 insertions(+)
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 7abf05131889..7cda749059a9 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -148,6 +148,8 @@ perf-$(CONFIG_ZLIB) += zlib.o
perf-$(CONFIG_LZMA) += lzma.o
perf-$(CONFIG_ZSTD) += zstd.o
+perf-$(CONFIG_LIBCAP) += cap.o
+
perf-y += demangle-java.o
perf-y += demangle-rust.o
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
new file mode 100644
index 000000000000..c3ba841bbf37
--- /dev/null
+++ b/tools/perf/util/cap.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Capability utilities
+ */
+
+#ifdef HAVE_LIBCAP_SUPPORT
+
+#include "cap.h"
+#include <stdbool.h>
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap)
+{
+ cap_flag_value_t val;
+ cap_t caps = cap_get_proc();
+
+ if (!caps)
+ return false;
+
+ if (cap_get_flag(caps, cap, CAP_EFFECTIVE, &val) != 0)
+ val = CAP_CLEAR;
+
+ if (cap_free(caps) != 0)
+ return false;
+
+ return val == CAP_SET;
+}
+
+#endif /* HAVE_LIBCAP_SUPPORT */
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h
new file mode 100644
index 000000000000..10af94e473da
--- /dev/null
+++ b/tools/perf/util/cap.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_CAP_H
+#define __PERF_CAP_H
+
+#include <stdbool.h>
+#include <linux/capability.h>
+#include <linux/compiler.h>
+
+#ifdef HAVE_LIBCAP_SUPPORT
+
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap);
+
+#else
+
+#include <unistd.h>
+#include <sys/types.h>
+
+static inline bool perf_cap__capable(int cap __maybe_unused)
+{
+ return geteuid() == 0;
+}
+
+#endif /* HAVE_LIBCAP_SUPPORT */
+
+#endif /* __PERF_CAP_H */
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 70841d115349..0e164e8ae28d 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -851,6 +851,7 @@ void cpu_map_data__synthesize(struct cpu_map_data *data, struct perf_cpu_map *m
void event_attr_init(struct perf_event_attr *attr);
int perf_event_paranoid(void);
+bool perf_event_paranoid_check(int max_level);
extern int sysctl_perf_event_max_stack;
extern int sysctl_perf_event_max_contexts_per_stack;
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index 235bd9803390..c6dd478956f1 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -7,6 +7,7 @@
util/python.c
../lib/ctype.c
+util/cap.c
util/evlist.c
util/evsel.c
util/cpumap.c
diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index d48f9cd58964..aa344a163eaf 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -59,6 +59,8 @@ ext_sources = list(map(lambda x: '%s/%s' % (src_perf, x) , ext_sources))
extra_libraries = []
if '-DHAVE_LIBNUMA_SUPPORT' in cflags:
extra_libraries = [ 'numa' ]
+if '-DHAVE_LIBCAP_SUPPORT' in cflags:
+ extra_libraries += [ 'cap' ]
perf = Extension('perf',
sources = ext_sources,
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 9c3c97697387..6fd130a5d8f2 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -16,10 +16,12 @@
#include <string.h>
#include <errno.h>
#include <limits.h>
+#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/time64.h>
#include <unistd.h>
+#include "cap.h"
#include "strlist.h"
#include "string2.h"
@@ -403,6 +405,13 @@ int perf_event_paranoid(void)
return value;
}
+
+bool perf_event_paranoid_check(int max_level)
+{
+ return perf_cap__capable(CAP_SYS_ADMIN) ||
+ perf_event_paranoid() <= max_level;
+}
+
static int
fetch_ubuntu_kernel_version(unsigned int *puint)
{
next prev parent reply other threads:[~2019-08-15 9:25 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-07 14:44 [PATCH v3 0/4] perf: Use capabilities instead of uid and euid Igor Lubashev
2019-08-07 14:44 ` [PATCH v3 1/4] perf: Add capability-related utilities Igor Lubashev
2019-08-12 19:43 ` Arnaldo Carvalho de Melo
2019-08-15 9:24 ` [tip:perf/core] tools build: Add capability-related feature detection tip-bot for Igor Lubashev
2019-08-15 9:25 ` tip-bot for Igor Lubashev [this message]
2019-08-07 14:44 ` [PATCH v3 2/4] perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks Igor Lubashev
2019-08-12 20:01 ` Arnaldo Carvalho de Melo
2019-08-12 20:15 ` Arnaldo Carvalho de Melo
2019-08-12 22:33 ` Lubashev, Igor
2019-08-13 13:20 ` Arnaldo Carvalho de Melo
2019-08-07 14:44 ` [PATCH v3 3/4] perf: Use CAP_SYSLOG with kptr_restrict checks Igor Lubashev
2019-08-14 18:04 ` Mathieu Poirier
2019-08-14 18:48 ` Arnaldo Carvalho de Melo
2019-08-14 18:52 ` Arnaldo Carvalho de Melo
2019-08-14 20:02 ` Lubashev, Igor
2019-08-15 15:01 ` Mathieu Poirier
2019-08-15 20:16 ` Mathieu Poirier
2019-08-15 21:42 ` Arnaldo Carvalho de Melo
2019-08-19 16:51 ` Mathieu Poirier
2019-08-19 22:22 ` Lubashev, Igor
2019-08-20 16:57 ` Mathieu Poirier
2019-08-20 17:13 ` Arnaldo Carvalho de Melo
2019-08-27 1:58 ` Lubashev, Igor
2019-08-15 22:27 ` Lubashev, Igor
2019-08-07 14:44 ` [PATCH v3 4/4] perf: Use CAP_SYS_ADMIN instead of euid==0 with ftrace Igor Lubashev
2019-08-12 20:22 ` Arnaldo Carvalho de Melo
2019-08-12 20:27 ` Arnaldo Carvalho de Melo
2019-08-12 20:29 ` Arnaldo Carvalho de Melo
2019-08-12 21:42 ` Mathieu Poirier
2019-08-13 13:23 ` Arnaldo Carvalho de Melo
2019-08-13 16:35 ` Mathieu Poirier
2019-08-15 9:27 ` [tip:perf/core] perf ftrace: Use CAP_SYS_ADMIN instead of euid==0 tip-bot for Igor Lubashev
2019-08-12 9:13 ` [PATCH v3 0/4] perf: Use capabilities instead of uid and euid Jiri Olsa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tip-c22e150e3afa6f8db2300bd510e4ac26bbee1bf3@git.kernel.org \
--to=tipbot@zytor.com \
--cc=acme@redhat.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=alexey.budankov@linux.intel.com \
--cc=hpa@zytor.com \
--cc=ilubashe@akamai.com \
--cc=jmorris@namei.org \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=mingo@kernel.org \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=suzuki.poulose@arm.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).