selftests: bpf: modify urandom_read and link it non-statically
After some experiences I found that urandom_read does not need to be
linked statically. When the 'read' syscall call is moved to separate
non-inlined function then bpf_get_stackid() is able to find
the executable in stack trace and extract its build_id from it.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c
index 9de8b7c..db78105 100644
--- a/tools/testing/selftests/bpf/urandom_read.c
+++ b/tools/testing/selftests/bpf/urandom_read.c
@@ -7,11 +7,19 @@
#define BUF_SIZE 256
+static __attribute__((noinline))
+void urandom_read(int fd, int count)
+{
+ char buf[BUF_SIZE];
+ int i;
+
+ for (i = 0; i < count; ++i)
+ read(fd, buf, BUF_SIZE);
+}
+
int main(int argc, char *argv[])
{
int fd = open("/dev/urandom", O_RDONLY);
- int i;
- char buf[BUF_SIZE];
int count = 4;
if (fd < 0)
@@ -20,8 +28,7 @@ int main(int argc, char *argv[])
if (argc == 2)
count = atoi(argv[1]);
- for (i = 0; i < count; ++i)
- read(fd, buf, BUF_SIZE);
+ urandom_read(fd, count);
close(fd);
return 0;