linux/tools/build/feature/test-bpf.c

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#include <asm/unistd.h>
bpf tools: Introduce 'bpf' library and add bpf feature check This is the first patch of libbpf. The goal of libbpf is to create a standard way for accessing eBPF object files. This patch creates 'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and libbpf.so, 'make install' to put them into proper directories. Most part of Makefile is borrowed from traceevent. Before building, it checks the existence of libelf in Makefile, and deny to build if not found. Instead of throwing an error if libelf not found, the error raises in a phony target "elfdep". This design is to ensure 'make clean' still workable even if libelf is not found. Because libbpf requires 'kern_version' field set for 'union bpf_attr' (bpfdep" is used for that dependency), Kernel BPF API is also checked by intruducing a new feature check 'bpf' into tools/build/feature, which checks the existence and version of linux/bpf.h. When building libbpf, it searches that file from include/uapi/linux in kernel source tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel source tree it reside, installing of newest kernel headers is not required, except we are trying to port these files to an old kernel. To avoid checking that file when perf building, the newly introduced 'bpf' feature check doesn't added into FEATURE_TESTS and FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added into libbpf's specific. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Bcc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 10:13:51 +08:00
#include <linux/bpf.h>
#include <unistd.h>
#ifndef __NR_bpf
# if defined(__i386__)
# define __NR_bpf 357
# elif defined(__x86_64__)
# define __NR_bpf 321
# elif defined(__aarch64__)
# define __NR_bpf 280
# elif defined(__sparc__)
# define __NR_bpf 349
# else
# error __NR_bpf not defined. libbpf does not support your arch.
# endif
#endif
bpf tools: Introduce 'bpf' library and add bpf feature check This is the first patch of libbpf. The goal of libbpf is to create a standard way for accessing eBPF object files. This patch creates 'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and libbpf.so, 'make install' to put them into proper directories. Most part of Makefile is borrowed from traceevent. Before building, it checks the existence of libelf in Makefile, and deny to build if not found. Instead of throwing an error if libelf not found, the error raises in a phony target "elfdep". This design is to ensure 'make clean' still workable even if libelf is not found. Because libbpf requires 'kern_version' field set for 'union bpf_attr' (bpfdep" is used for that dependency), Kernel BPF API is also checked by intruducing a new feature check 'bpf' into tools/build/feature, which checks the existence and version of linux/bpf.h. When building libbpf, it searches that file from include/uapi/linux in kernel source tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel source tree it reside, installing of newest kernel headers is not required, except we are trying to port these files to an old kernel. To avoid checking that file when perf building, the newly introduced 'bpf' feature check doesn't added into FEATURE_TESTS and FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added into libbpf's specific. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Bcc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 10:13:51 +08:00
int main(void)
{
union bpf_attr attr;
/* Check fields in attr */
bpf tools: Introduce 'bpf' library and add bpf feature check This is the first patch of libbpf. The goal of libbpf is to create a standard way for accessing eBPF object files. This patch creates 'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and libbpf.so, 'make install' to put them into proper directories. Most part of Makefile is borrowed from traceevent. Before building, it checks the existence of libelf in Makefile, and deny to build if not found. Instead of throwing an error if libelf not found, the error raises in a phony target "elfdep". This design is to ensure 'make clean' still workable even if libelf is not found. Because libbpf requires 'kern_version' field set for 'union bpf_attr' (bpfdep" is used for that dependency), Kernel BPF API is also checked by intruducing a new feature check 'bpf' into tools/build/feature, which checks the existence and version of linux/bpf.h. When building libbpf, it searches that file from include/uapi/linux in kernel source tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel source tree it reside, installing of newest kernel headers is not required, except we are trying to port these files to an old kernel. To avoid checking that file when perf building, the newly introduced 'bpf' feature check doesn't added into FEATURE_TESTS and FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added into libbpf's specific. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Bcc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 10:13:51 +08:00
attr.prog_type = BPF_PROG_TYPE_KPROBE;
attr.insn_cnt = 0;
attr.insns = 0;
attr.license = 0;
attr.log_buf = 0;
attr.log_size = 0;
attr.log_level = 0;
attr.kern_version = 0;
/*
* Test existence of __NR_bpf and BPF_PROG_LOAD.
* This call should fail if we run the testcase.
*/
return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
bpf tools: Introduce 'bpf' library and add bpf feature check This is the first patch of libbpf. The goal of libbpf is to create a standard way for accessing eBPF object files. This patch creates 'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and libbpf.so, 'make install' to put them into proper directories. Most part of Makefile is borrowed from traceevent. Before building, it checks the existence of libelf in Makefile, and deny to build if not found. Instead of throwing an error if libelf not found, the error raises in a phony target "elfdep". This design is to ensure 'make clean' still workable even if libelf is not found. Because libbpf requires 'kern_version' field set for 'union bpf_attr' (bpfdep" is used for that dependency), Kernel BPF API is also checked by intruducing a new feature check 'bpf' into tools/build/feature, which checks the existence and version of linux/bpf.h. When building libbpf, it searches that file from include/uapi/linux in kernel source tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel source tree it reside, installing of newest kernel headers is not required, except we are trying to port these files to an old kernel. To avoid checking that file when perf building, the newly introduced 'bpf' feature check doesn't added into FEATURE_TESTS and FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added into libbpf's specific. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Bcc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 10:13:51 +08:00
}