bpf: unify rlimit handling in selftests

Unify memlock handling into bpf_rlimit.h and replace all occurences
in BPF kselftests with it.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/bpf_rlimit.h b/tools/testing/selftests/bpf/bpf_rlimit.h
new file mode 100644
index 000000000000..9dac9b30f8ef
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_rlimit.h
@@ -0,0 +1,28 @@
+#include <sys/resource.h>
+#include <stdio.h>
+
+static  __attribute__((constructor)) void bpf_rlimit_ctor(void)
+{
+	struct rlimit rlim_old, rlim_new = {
+		.rlim_cur	= RLIM_INFINITY,
+		.rlim_max	= RLIM_INFINITY,
+	};
+
+	getrlimit(RLIMIT_MEMLOCK, &rlim_old);
+	/* For the sake of running the test cases, we temporarily
+	 * set rlimit to infinity in order for kernel to focus on
+	 * errors from actual test cases and not getting noise
+	 * from hitting memlock limits. The limit is on per-process
+	 * basis and not a global one, hence destructor not really
+	 * needed here.
+	 */
+	if (setrlimit(RLIMIT_MEMLOCK, &rlim_new) < 0) {
+		perror("Unable to lift memlock rlimit");
+		/* Trying out lower limit, but expect potential test
+		 * case failures from this!
+		 */
+		rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20);
+		rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20);
+		setrlimit(RLIMIT_MEMLOCK, &rlim_new);
+	}
+}