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 da2172ff9662d0e86ffd132b6041b30ea232eb87..dfd70d2471afbdcdf5eb70df51c5de05e881be68 100644 (file)
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -33,9 +33,5 @@ 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;
 }