Add utilities to help checking capabilities of the running process.
Make perf link with libcap.
Signed-off-by: Igor Lubashev <[email protected]>
---
tools/perf/Makefile.config | 2 +-
tools/perf/util/Build | 1 +
tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
tools/perf/util/cap.h | 10 ++++++++++
tools/perf/util/event.h | 1 +
tools/perf/util/python-ext-sources | 1 +
tools/perf/util/util.c | 9 +++++++++
7 files changed, 47 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/util/cap.c
create mode 100644 tools/perf/util/cap.h
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 85fbcd265351..21470a50ed39 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
# adding assembler files missing the .GNU-stack linker note.
LDFLAGS += -Wl,-z,noexecstack
-EXTLIBS = -lpthread -lrt -lm -ldl
+EXTLIBS = -lpthread -lrt -lm -ldl -lcap
ifeq ($(FEATURES_DUMP),)
include $(srctree)/tools/build/Makefile.feature
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 6d5bbc8b589b..9cc6e9b34ebd 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -1,6 +1,7 @@
perf-y += annotate.o
perf-y += block-range.o
perf-y += build-id.o
+perf-y += cap.o
perf-y += config.o
perf-y += ctype.o
perf-y += db-export.o
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
new file mode 100644
index 000000000000..c42ea32663cf
--- /dev/null
+++ b/tools/perf/util/cap.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Capability utilities
+ */
+#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;
+}
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h
new file mode 100644
index 000000000000..5521de78b228
--- /dev/null
+++ b/tools/perf/util/cap.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_CAP_H
+#define __PERF_CAP_H
+
+#include <stdbool.h>
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap);
+
+#endif /* __PERF_CAP_H */
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 9e999550f247..013d9e28fcac 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -849,6 +849,7 @@ void cpu_map_data__synthesize(struct cpu_map_data *data, struct cpu_map *map,
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 7aa0ea64544e..4545eaf018b5 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -6,6 +6,7 @@
#
util/python.c
+util/cap.c
util/ctype.c
util/evlist.c
util/evsel.c
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index d388f80d8703..cde538ec727d 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"
@@ -456,6 +458,13 @@ 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)
{
--
2.7.4
On Tue, Jul 02, 2019 at 08:10:03PM -0400, Igor Lubashev wrote:
> Add utilities to help checking capabilities of the running process.
> Make perf link with libcap.
>
> Signed-off-by: Igor Lubashev <[email protected]>
> ---
> tools/perf/Makefile.config | 2 +-
> tools/perf/util/Build | 1 +
> tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
> tools/perf/util/cap.h | 10 ++++++++++
> tools/perf/util/event.h | 1 +
> tools/perf/util/python-ext-sources | 1 +
> tools/perf/util/util.c | 9 +++++++++
> 7 files changed, 47 insertions(+), 1 deletion(-)
> create mode 100644 tools/perf/util/cap.c
> create mode 100644 tools/perf/util/cap.h
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 85fbcd265351..21470a50ed39 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
> # adding assembler files missing the .GNU-stack linker note.
> LDFLAGS += -Wl,-z,noexecstack
>
> -EXTLIBS = -lpthread -lrt -lm -ldl
> +EXTLIBS = -lpthread -lrt -lm -ldl -lcap
I wonder we should detect libcap or it's everywhere.. Arnaldo's compile test suite might tell
jirka
Em Tue, Jul 16, 2019 at 10:46:43AM +0200, Jiri Olsa escreveu:
> On Tue, Jul 02, 2019 at 08:10:03PM -0400, Igor Lubashev wrote:
> > Add utilities to help checking capabilities of the running process.
> > Make perf link with libcap.
> >
> > Signed-off-by: Igor Lubashev <[email protected]>
> > ---
> > tools/perf/Makefile.config | 2 +-
> > tools/perf/util/Build | 1 +
> > tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
> > tools/perf/util/cap.h | 10 ++++++++++
> > tools/perf/util/event.h | 1 +
> > tools/perf/util/python-ext-sources | 1 +
> > tools/perf/util/util.c | 9 +++++++++
> > 7 files changed, 47 insertions(+), 1 deletion(-)
> > create mode 100644 tools/perf/util/cap.c
> > create mode 100644 tools/perf/util/cap.h
> >
> > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > index 85fbcd265351..21470a50ed39 100644
> > --- a/tools/perf/Makefile.config
> > +++ b/tools/perf/Makefile.config
> > @@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
> > # adding assembler files missing the .GNU-stack linker note.
> > LDFLAGS += -Wl,-z,noexecstack
> >
> > -EXTLIBS = -lpthread -lrt -lm -ldl
> > +EXTLIBS = -lpthread -lrt -lm -ldl -lcap
>
> I wonder we should detect libcap or it's everywhere.. Arnaldo's compile test suite might tell
I'll add this tentatively and try to build it in my test suite.
- Arnaldo
Em Wed, Jul 17, 2019 at 06:05:51PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Jul 16, 2019 at 10:46:43AM +0200, Jiri Olsa escreveu:
> > On Tue, Jul 02, 2019 at 08:10:03PM -0400, Igor Lubashev wrote:
> > > Add utilities to help checking capabilities of the running process.
> > > Make perf link with libcap.
> > >
> > > Signed-off-by: Igor Lubashev <[email protected]>
> > > ---
> > > tools/perf/Makefile.config | 2 +-
> > > tools/perf/util/Build | 1 +
> > > tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
> > > tools/perf/util/cap.h | 10 ++++++++++
> > > tools/perf/util/event.h | 1 +
> > > tools/perf/util/python-ext-sources | 1 +
> > > tools/perf/util/util.c | 9 +++++++++
> > > 7 files changed, 47 insertions(+), 1 deletion(-)
> > > create mode 100644 tools/perf/util/cap.c
> > > create mode 100644 tools/perf/util/cap.h
> > >
> > > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > > index 85fbcd265351..21470a50ed39 100644
> > > --- a/tools/perf/Makefile.config
> > > +++ b/tools/perf/Makefile.config
> > > @@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
> > > # adding assembler files missing the .GNU-stack linker note.
> > > LDFLAGS += -Wl,-z,noexecstack
> > >
> > > -EXTLIBS = -lpthread -lrt -lm -ldl
> > > +EXTLIBS = -lpthread -lrt -lm -ldl -lcap
> >
> > I wonder we should detect libcap or it's everywhere.. Arnaldo's compile test suite might tell
>
> I'll add this tentatively and try to build it in my test suite.
So, not even in my notebook this worked straight away:
CC /tmp/build/perf/util/cap.o
CC /tmp/build/perf/util/config.o
In file included from util/cap.c:5:
util/cap.h:6:10: fatal error: sys/capability.h: No such file or directory
6 | #include <sys/capability.h>
| ^~~~~~~~~~~~~~~~~~
compilation terminated.
mv: cannot stat '/tmp/build/perf/util/.cap.o.tmp': No such file or directory
I had to first do:
dnf install libcap-devel
So we need to have a feature test and fail if that is not installed,
i.e. libcap becomes a hard req for building perf, which I think is
reasonable, one more shouldn't hurt, right?
With all the features enabled:
[acme@quaco perf]$ ldd ~/bin/perf
linux-vdso.so.1 (0x00007ffe7278a000)
libunwind-x86_64.so.8 => /lib64/libunwind-x86_64.so.8 (0x00007f7be52f1000)
libunwind.so.8 => /lib64/libunwind.so.8 (0x00007f7be52d7000)
liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f7be52ae000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f7be528d000)
librt.so.1 => /lib64/librt.so.1 (0x00007f7be5283000)
libm.so.6 => /lib64/libm.so.6 (0x00007f7be513d000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f7be5135000)
libcap.so.2 => /lib64/libcap.so.2 (0x00007f7be512e000)
libelf.so.1 => /lib64/libelf.so.1 (0x00007f7be5113000)
libdw.so.1 => /lib64/libdw.so.1 (0x00007f7be50c0000)
libslang.so.2 => /lib64/libslang.so.2 (0x00007f7be4de8000)
libperl.so.5.28 => /lib64/libperl.so.5.28 (0x00007f7be4ac2000)
libc.so.6 => /lib64/libc.so.6 (0x00007f7be48fa000)
libpython2.7.so.1.0 => /lib64/libpython2.7.so.1.0 (0x00007f7be4690000)
libz.so.1 => /lib64/libz.so.1 (0x00007f7be4676000)
libzstd.so.1 => /lib64/libzstd.so.1 (0x00007f7be45d1000)
libnuma.so.1 => /lib64/libnuma.so.1 (0x00007f7be45c3000)
libbabeltrace-ctf.so.1 => /lib64/libbabeltrace-ctf.so.1 (0x00007f7be456d000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f7be4551000)
/lib64/ld-linux-x86-64.so.2 (0x00007f7be5331000)
libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f7be453d000)
libcrypt.so.2 => /lib64/libcrypt.so.2 (0x00007f7be4502000)
libutil.so.1 => /lib64/libutil.so.1 (0x00007f7be44fd000)
libbabeltrace.so.1 => /lib64/libbabeltrace.so.1 (0x00007f7be44ed000)
libpopt.so.0 => /lib64/libpopt.so.0 (0x00007f7be44dd000)
libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f7be44d3000)
libgmodule-2.0.so.0 => /lib64/libgmodule-2.0.so.0 (0x00007f7be44cd000)
libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x00007f7be43a9000)
libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f7be4335000)
[acme@quaco perf]$
;-)
So, please check tools/build/feature/ and check how this is done and add
a test and the warning in tools/perf/Makefile.config so that we get an
error message stating that libcap-dev or libcap-devel should be
installed.
I'll do it if there is any difficulty, just not right now as I'm busy
and want to get a pull req out of the door.
- Arnaldo
Em Wed, Jul 17, 2019 at 08:46:52PM -0300, Arnaldo Carvalho de Melo escreveu:
> I'll do it if there is any difficulty, just not right now as I'm busy
> and want to get a pull req out of the door.
Also please find the first patch fixed up wrt a conflict with the
pythong binding, please use it instead as that is what applies to my
current perf/core branch.
It has the ack from Alexey and one I think Jiri would provide, judging
from his positive tone to the patches :)
- Arnaldo
commit 8048a0884a3f98bae2434d141711d72382b784b0
Author: Igor Lubashev <[email protected]>
Date: Wed Jul 17 20:39:03 2019 -0300
perf tools: Add capability-related utilities
Add utilities to help checking capabilities of the running process.
Make perf link with libcap.
Signed-off-by: Igor Lubashev <[email protected]>
Acked-by: Alexey Budankov <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
CC: Alexander Shishkin <[email protected]>
Cc: James Morris <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suzuki K Poulose <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 89ac5a1f1550..b9cf084f32d7 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
# adding assembler files missing the .GNU-stack linker note.
LDFLAGS += -Wl,-z,noexecstack
-EXTLIBS = -lpthread -lrt -lm -ldl
+EXTLIBS = -lpthread -lrt -lm -ldl -lcap
ifeq ($(FEATURES_DUMP),)
include $(srctree)/tools/build/Makefile.feature
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 14f812bb07a7..61ed1a3005d4 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -1,6 +1,7 @@
perf-y += annotate.o
perf-y += block-range.o
perf-y += build-id.o
+perf-y += cap.o
perf-y += config.o
perf-y += ctype.o
perf-y += db-export.o
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
new file mode 100644
index 000000000000..c42ea32663cf
--- /dev/null
+++ b/tools/perf/util/cap.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Capability utilities
+ */
+#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;
+}
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h
new file mode 100644
index 000000000000..5521de78b228
--- /dev/null
+++ b/tools/perf/util/cap.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_CAP_H
+#define __PERF_CAP_H
+
+#include <stdbool.h>
+#include <sys/capability.h>
+
+bool perf_cap__capable(cap_value_t cap);
+
+#endif /* __PERF_CAP_H */
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 1f1da6082806..b4128f72f2e8 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 cpu_map *map,
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 ceb8afdf9a89..afba10684b65 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -9,6 +9,7 @@ util/python.c
../lib/ctype.c
util/evlist.c
util/evsel.c
+util/cap.c
util/cpumap.c
util/memswap.c
util/mmap.c
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index a61535cf1bca..4f0da8a03697 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"
@@ -443,6 +445,13 @@ 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)
{
Thanks for the suggestion! I'll try to add a test for libcap to the patch series as v2 of the series. Probably not next week, though (IETF week).
- Igor
> On Wed, July 17, 2019 7:47 PM Arnaldo Carvalho de Melo wrote:
>
> Em Wed, Jul 17, 2019 at 06:05:51PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Tue, Jul 16, 2019 at 10:46:43AM +0200, Jiri Olsa escreveu:
> > > On Tue, Jul 02, 2019 at 08:10:03PM -0400, Igor Lubashev wrote:
> > > > Add utilities to help checking capabilities of the running process.
> > > > Make perf link with libcap.
> > > >
> > > > Signed-off-by: Igor Lubashev <[email protected]>
> > > > ---
> > > > tools/perf/Makefile.config | 2 +-
> > > > tools/perf/util/Build | 1 +
> > > > tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
> > > > tools/perf/util/cap.h | 10 ++++++++++
> > > > tools/perf/util/event.h | 1 +
> > > > tools/perf/util/python-ext-sources | 1 +
> > > > tools/perf/util/util.c | 9 +++++++++
> > > > 7 files changed, 47 insertions(+), 1 deletion(-)
> > > > create mode 100644 tools/perf/util/cap.c
> > > > create mode 100644 tools/perf/util/cap.h
> > > >
> > > > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > > > index 85fbcd265351..21470a50ed39 100644
> > > > --- a/tools/perf/Makefile.config
> > > > +++ b/tools/perf/Makefile.config
> > > > @@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing
> > > > # adding assembler files missing the .GNU-stack linker note.
> > > > LDFLAGS += -Wl,-z,noexecstack
> > > >
> > > > -EXTLIBS = -lpthread -lrt -lm -ldl
> > > > +EXTLIBS = -lpthread -lrt -lm -ldl -lcap
> > >
> > > I wonder we should detect libcap or it's everywhere.. Arnaldo's compile test
> suite might tell
> >
> > I'll add this tentatively and try to build it in my test suite.
>
> So, not even in my notebook this worked straight away:
>
> CC /tmp/build/perf/util/cap.o
> CC /tmp/build/perf/util/config.o
> In file included from util/cap.c:5:
> util/cap.h:6:10: fatal error: sys/capability.h: No such file or directory
> 6 | #include <sys/capability.h>
> | ^~~~~~~~~~~~~~~~~~
> compilation terminated.
> mv: cannot stat '/tmp/build/perf/util/.cap.o.tmp': No such file or directory
>
>
> I had to first do:
>
> dnf install libcap-devel
>
> So we need to have a feature test and fail if that is not installed,
> i.e. libcap becomes a hard req for building perf, which I think is
> reasonable, one more shouldn't hurt, right?
>
> With all the features enabled:
>
> [acme@quaco perf]$ ldd ~/bin/perf
> linux-vdso.so.1 (0x00007ffe7278a000)
> libunwind-x86_64.so.8 => /lib64/libunwind-x86_64.so.8
> (0x00007f7be52f1000)
> libunwind.so.8 => /lib64/libunwind.so.8 (0x00007f7be52d7000)
> liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f7be52ae000)
> libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f7be528d000)
> librt.so.1 => /lib64/librt.so.1 (0x00007f7be5283000)
> libm.so.6 => /lib64/libm.so.6 (0x00007f7be513d000)
> libdl.so.2 => /lib64/libdl.so.2 (0x00007f7be5135000)
> libcap.so.2 => /lib64/libcap.so.2 (0x00007f7be512e000)
> libelf.so.1 => /lib64/libelf.so.1 (0x00007f7be5113000)
> libdw.so.1 => /lib64/libdw.so.1 (0x00007f7be50c0000)
> libslang.so.2 => /lib64/libslang.so.2 (0x00007f7be4de8000)
> libperl.so.5.28 => /lib64/libperl.so.5.28 (0x00007f7be4ac2000)
> libc.so.6 => /lib64/libc.so.6 (0x00007f7be48fa000)
> libpython2.7.so.1.0 => /lib64/libpython2.7.so.1.0 (0x00007f7be4690000)
> libz.so.1 => /lib64/libz.so.1 (0x00007f7be4676000)
> libzstd.so.1 => /lib64/libzstd.so.1 (0x00007f7be45d1000)
> libnuma.so.1 => /lib64/libnuma.so.1 (0x00007f7be45c3000)
> libbabeltrace-ctf.so.1 => /lib64/libbabeltrace-ctf.so.1
> (0x00007f7be456d000)
> libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f7be4551000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f7be5331000)
> libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f7be453d000)
> libcrypt.so.2 => /lib64/libcrypt.so.2 (0x00007f7be4502000)
> libutil.so.1 => /lib64/libutil.so.1 (0x00007f7be44fd000)
> libbabeltrace.so.1 => /lib64/libbabeltrace.so.1 (0x00007f7be44ed000)
> libpopt.so.0 => /lib64/libpopt.so.0 (0x00007f7be44dd000)
> libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f7be44d3000)
> libgmodule-2.0.so.0 => /lib64/libgmodule-2.0.so.0 (0x00007f7be44cd000)
> libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x00007f7be43a9000)
> libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f7be4335000)
> [acme@quaco perf]$
>
> ;-)
>
> So, please check tools/build/feature/ and check how this is done and add
> a test and the warning in tools/perf/Makefile.config so that we get an
> error message stating that libcap-dev or libcap-devel should be
> installed.
>
> I'll do it if there is any difficulty, just not right now as I'm busy
> and want to get a pull req out of the door.
>
> - Arnaldo
On Wed, July 17 at 2019 7:47 PM Arnaldo Carvalho de Melo wrote:
> Em Wed, Jul 17, 2019 at 06:05:51PM -0300, Arnaldo Carvalho de Melo
> escreveu:
> > Em Tue, Jul 16, 2019 at 10:46:43AM +0200, Jiri Olsa escreveu:
> > > On Tue, Jul 02, 2019 at 08:10:03PM -0400, Igor Lubashev wrote:
> > > > Add utilities to help checking capabilities of the running process.
> > > > Make perf link with libcap.
> > > >
> > > > Signed-off-by: Igor Lubashev <[email protected]>
> > > > ---
> > > > tools/perf/Makefile.config | 2 +-
> > > > tools/perf/util/Build | 1 +
> > > > tools/perf/util/cap.c | 24 ++++++++++++++++++++++++
> > > > tools/perf/util/cap.h | 10 ++++++++++
> > > > tools/perf/util/event.h | 1 +
> > > > tools/perf/util/python-ext-sources | 1 +
> > > > tools/perf/util/util.c | 9 +++++++++
> > > > 7 files changed, 47 insertions(+), 1 deletion(-) create mode
> > > > 100644 tools/perf/util/cap.c create mode 100644
> > > > tools/perf/util/cap.h
> > > >
> > > > diff --git a/tools/perf/Makefile.config
> > > > b/tools/perf/Makefile.config index 85fbcd265351..21470a50ed39
> > > > 100644
> > > > --- a/tools/perf/Makefile.config
> > > > +++ b/tools/perf/Makefile.config
> > > > @@ -259,7 +259,7 @@ CXXFLAGS += -Wno-strict-aliasing # adding
> > > > assembler files missing the .GNU-stack linker note.
> > > > LDFLAGS += -Wl,-z,noexecstack
> > > >
> > > > -EXTLIBS = -lpthread -lrt -lm -ldl
> > > > +EXTLIBS = -lpthread -lrt -lm -ldl -lcap
> > >
> > > I wonder we should detect libcap or it's everywhere.. Arnaldo's
> > > compile test suite might tell
> >
> > I'll add this tentatively and try to build it in my test suite.
>
> So, not even in my notebook this worked straight away:
>
> CC /tmp/build/perf/util/cap.o
> CC /tmp/build/perf/util/config.o
> In file included from util/cap.c:5:
> util/cap.h:6:10: fatal error: sys/capability.h: No such file or directory
> 6 | #include <sys/capability.h>
> | ^~~~~~~~~~~~~~~~~~
> compilation terminated.
> mv: cannot stat '/tmp/build/perf/util/.cap.o.tmp': No such file or directory
>
>
> I had to first do:
>
> dnf install libcap-devel
>
> So we need to have a feature test and fail if that is not installed, i.e. libcap
> becomes a hard req for building perf, which I think is reasonable, one more
> shouldn't hurt, right?
>
> With all the features enabled:
>
> [acme@quaco perf]$ ldd ~/bin/perf
> linux-vdso.so.1 (0x00007ffe7278a000)
> libunwind-x86_64.so.8 => /lib64/libunwind-x86_64.so.8
> (0x00007f7be52f1000)
> libunwind.so.8 => /lib64/libunwind.so.8 (0x00007f7be52d7000)
> liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f7be52ae000)
> libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f7be528d000)
> librt.so.1 => /lib64/librt.so.1 (0x00007f7be5283000)
> libm.so.6 => /lib64/libm.so.6 (0x00007f7be513d000)
> libdl.so.2 => /lib64/libdl.so.2 (0x00007f7be5135000)
> libcap.so.2 => /lib64/libcap.so.2 (0x00007f7be512e000)
> libelf.so.1 => /lib64/libelf.so.1 (0x00007f7be5113000)
> libdw.so.1 => /lib64/libdw.so.1 (0x00007f7be50c0000)
> libslang.so.2 => /lib64/libslang.so.2 (0x00007f7be4de8000)
> libperl.so.5.28 => /lib64/libperl.so.5.28 (0x00007f7be4ac2000)
> libc.so.6 => /lib64/libc.so.6 (0x00007f7be48fa000)
> libpython2.7.so.1.0 => /lib64/libpython2.7.so.1.0
> (0x00007f7be4690000)
> libz.so.1 => /lib64/libz.so.1 (0x00007f7be4676000)
> libzstd.so.1 => /lib64/libzstd.so.1 (0x00007f7be45d1000)
> libnuma.so.1 => /lib64/libnuma.so.1 (0x00007f7be45c3000)
> libbabeltrace-ctf.so.1 => /lib64/libbabeltrace-ctf.so.1
> (0x00007f7be456d000)
> libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f7be4551000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f7be5331000)
> libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f7be453d000)
> libcrypt.so.2 => /lib64/libcrypt.so.2 (0x00007f7be4502000)
> libutil.so.1 => /lib64/libutil.so.1 (0x00007f7be44fd000)
> libbabeltrace.so.1 => /lib64/libbabeltrace.so.1
> (0x00007f7be44ed000)
> libpopt.so.0 => /lib64/libpopt.so.0 (0x00007f7be44dd000)
> libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f7be44d3000)
> libgmodule-2.0.so.0 => /lib64/libgmodule-2.0.so.0
> (0x00007f7be44cd000)
> libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x00007f7be43a9000)
> libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f7be4335000)
> [acme@quaco perf]$
>
> ;-)
>
> So, please check tools/build/feature/ and check how this is done and add a
> test and the warning in tools/perf/Makefile.config so that we get an error
> message stating that libcap-dev or libcap-devel should be installed.
I have just posted v2 of the series (https://lkml.kernel.org/lkml/[email protected]).
Instead of making libcap is "hard req", I made it as "soft" one. We can still build a useful tool w/o libcap. It will just have to assume that perf is running with no capabilities, since we cannot query them.
Many thanks for the pointers on how to go about build feature checking.
- Igor