tools/build: Remove bpf() run-time check at build time

It is not correct to test that a syscall works on the build system's
kernel.  We might be building on an earlier kernel version or with
security restrictions that block bpf().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name tools-build-remove-bpf-run-time-check-at-build-time.patch

diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c
index 82070eadfc070ffdadc4e729950ab7ae386dfab1..6aa2eb9abd52d156e946d5c04d1628db4ce8ff1d 100644 (file)
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -34,9 +34,5 @@ int main(void)
        attr.kern_version = 0;
        attr.prog_flags = 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));
+       return 0;
 }