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author | Igor Lubashev <ilubashe@akamai.com> | 2019-08-07 10:44:14 -0400 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-08-12 17:14:14 -0300 |
commit | 74d5f3d06f707eb5f7e1908ad88954bde02000ce (patch) | |
tree | 57525abd1ec4aaea45d25c11a1adfecdc0c62d18 /tools/build/feature | |
parent | 40d81772dac45643cecc7add0e95356072265754 (diff) | |
download | linux-74d5f3d06f707eb5f7e1908ad88954bde02000ce.tar.bz2 |
tools build: Add capability-related feature detection
Add utilities to help checking capabilities of the running procss. Make
perf link with libcap, if it is available. If no libcap-dev[el], assume
no capabilities.
Committer testing:
$ make O=/tmp/build/perf -C tools/perf install-bin
make: Entering directory '/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j8' parallel build
Auto-detecting system features:
<SNIP>
... libbfd: [ on ]
... libcap: [ OFF ]
... libelf: [ on ]
<SNIP>
Makefile.config:833: No libcap found, disables capability support, please install libcap-devel/libcap-dev
<SNIP>
$ grep libcap /tmp/build/perf/FEATURE-DUMP
feature-libcap=0
$ cat /tmp/build/perf/feature/test-libcap.make.output
test-libcap.c:2:10: fatal error: sys/capability.h: No such file or directory
2 | #include <sys/capability.h>
| ^~~~~~~~~~~~~~~~~~
compilation terminated.
$
Now install libcap-devel and try again:
$ make O=/tmp/build/perf -C tools/perf install-bin
make: Entering directory '/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j8' parallel build
Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h'
diff -u tools/include/linux/bits.h include/linux/bits.h
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
Auto-detecting system features:
<SNIP>
... libbfd: [ on ]
... libcap: [ on ]
... libelf: [ on ]
<SNIP>>
CC /tmp/build/perf/jvmti/libjvmti.o
<SNIP>>
$ grep libcap /tmp/build/perf/FEATURE-DUMP
feature-libcap=1
$ cat /tmp/build/perf/feature/test-libcap.make.output
$ ldd /tmp/build/perf/feature/test-libcap.make.bin
ldd: /tmp/build/perf/feature/test-libcap.make.bin: No such file or directory
$ ldd /tmp/build/perf/feature/test-libcap.bin
linux-vdso.so.1 (0x00007ffc35bfe000)
libcap.so.2 => /lib64/libcap.so.2 (0x00007ff9c62ff000)
libc.so.6 => /lib64/libc.so.6 (0x00007ff9c6139000)
/lib64/ld-linux-x86-64.so.2 (0x00007ff9c6326000)
$
Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
[ 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>
Diffstat (limited to 'tools/build/feature')
-rw-r--r-- | tools/build/feature/Makefile | 4 | ||||
-rw-r--r-- | tools/build/feature/test-libcap.c | 20 |
2 files changed, 24 insertions, 0 deletions
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 0658b8cd0e53..8499385365c0 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -20,6 +20,7 @@ FILES= \ test-libbfd-liberty.bin \ test-libbfd-liberty-z.bin \ test-cplus-demangle.bin \ + test-libcap.bin \ test-libelf.bin \ test-libelf-getphdrnum.bin \ test-libelf-gelf_getnote.bin \ @@ -105,6 +106,9 @@ $(OUTPUT)test-fortify-source.bin: $(OUTPUT)test-bionic.bin: $(BUILD) +$(OUTPUT)test-libcap.bin: + $(BUILD) -lcap + $(OUTPUT)test-libelf.bin: $(BUILD) -lelf diff --git a/tools/build/feature/test-libcap.c b/tools/build/feature/test-libcap.c new file mode 100644 index 000000000000..d2a2e152195f --- /dev/null +++ b/tools/build/feature/test-libcap.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <sys/capability.h> +#include <linux/capability.h> + +int main(void) +{ + cap_flag_value_t val; + cap_t caps = cap_get_proc(); + + if (!caps) + return 1; + + if (cap_get_flag(caps, CAP_SYS_ADMIN, CAP_EFFECTIVE, &val) != 0) + return 1; + + if (cap_free(caps) != 0) + return 1; + + return 0; +} |