From 74d5f3d06f707eb5f7e1908ad88954bde02000ce Mon Sep 17 00:00:00 2001 From: Igor Lubashev Date: Wed, 7 Aug 2019 10:44:14 -0400 Subject: 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: ... libbfd: [ on ] ... libcap: [ OFF ] ... libelf: [ on ] Makefile.config:833: No libcap found, disables capability support, please install libcap-devel/libcap-dev $ 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 | ^~~~~~~~~~~~~~~~~~ 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: ... libbfd: [ on ] ... libcap: [ on ] ... libelf: [ on ] > CC /tmp/build/perf/jvmti/libjvmti.o > $ 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 Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Alexey Budankov Cc: James Morris Cc: Mathieu Poirier Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse [ split from a larger patch ] Link: http://lkml.kernel.org/r/8a1e76cf5c7c9796d0d4d240fbaa85305298aafa.1565188228.git.ilubashe@akamai.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/build/Makefile.feature | 2 ++ tools/build/feature/Makefile | 4 ++++ tools/build/feature/test-libcap.c | 20 ++++++++++++++++++++ 3 files changed, 26 insertions(+) create mode 100644 tools/build/feature/test-libcap.c (limited to 'tools/build') diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 86b793dffbc4..8a19753cc26a 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -42,6 +42,7 @@ FEATURE_TESTS_BASIC := \ gtk2-infobar \ libaudit \ libbfd \ + libcap \ libelf \ libelf-getphdrnum \ libelf-gelf_getnote \ @@ -110,6 +111,7 @@ FEATURE_DISPLAY ?= \ gtk2 \ libaudit \ libbfd \ + libcap \ libelf \ libnuma \ numa_num_possible_cpus \ 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 +#include + +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; +} -- cgit v1.2.3-59-g8ed1b