tests: increase the bpf test's RLIMIT_MEMLOCK value

Some architectures, aarch64 specifically, need a higher
RLIMIT_MEMLOCK than may commonly be set by the distribution.  This
patch attempts to increase the limit to "infinity" to solve this
problem.

Signed-off-by: Paul Moore <[email protected]>

tests/bpf/bpf.c

@@ -1,8 +1,11 @@
+#include <errno.h>
 #include <string.h>
 #include <linux/filter.h>
 #include <linux/bpf.h>
 #include <unistd.h>
 #include <sys/syscall.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 
 #define BPF_EXIT_INSN() \
 	((struct bpf_insn) { .code = BPF_JMP | BPF_EXIT, .dst_reg = 0, .src_reg = 0, .off = 0, .imm = 0 })
@@ -15,18 +18,38 @@ static inline __u64 ptr_to_u64(const void *ptr)
 	return (__u64) (unsigned long) ptr;
 }
 
+int rlimit_fix(void)
+{
+	struct rlimit limit = {
+		.rlim_cur = RLIM_INFINITY, .rlim_max = RLIM_INFINITY
+	};
+
+	if (setrlimit(RLIMIT_MEMLOCK, &limit))
+		return errno;
+
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
+	int rc;
 	struct bpf_insn insns[] = {
 		BPF_MOV64_IMM(BPF_REG_0, 0),
 		BPF_EXIT_INSN(),
 	};
 	union bpf_attr attr;
 
+	rc = rlimit_fix();
+	if (rc)
+		return rc;
+
 	memset(&attr, 0, sizeof(attr));
 	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
 	attr.insn_cnt = 2;
 	attr.insns = ptr_to_u64(insns);
 	attr.license = ptr_to_u64("GPL");
-	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)) >= 0 ? 0 : -1;
+	if (syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr)))
+		return errno;
+
+	return 0;
 }