[PATCH v2] libtraceevent: read btf file in utest if mmap fails

When mmap of the btf file fails in utest, fall back to malloc and
read.

This mmap fails with ENODEV on i686 nix build on nixos-unstable.

Signed-off-by: Emil Thorsoe <[email protected]>
---
 utest/traceevent-utest.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/utest/traceevent-utest.c b/utest/traceevent-utest.c
index b62411c..7d09bf2 100644
--- a/utest/traceevent-utest.c
+++ b/utest/traceevent-utest.c
@@ -388,6 +388,7 @@ static void test_btf_read(void)
 	struct stat st;
 	void *buf;
 	int fd, nr = 6;
+	bool malloced = false;
 
 	fd = open("/sys/kernel/btf/vmlinux", O_RDONLY);
 	if (fd < 0) {
@@ -397,11 +398,23 @@ static void test_btf_read(void)
 	CU_TEST(fstat(fd, &st) == 0);
 
 	buf = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	CU_TEST(buf != MAP_FAILED);
-
+	if (buf == MAP_FAILED) {
+		malloced = true;
+		buf = malloc(st.st_size);
+		if (buf == NULL) {
+			printf("[FAILED TO ALLOCATE MEMORY FOR BTF FILE CONTENTS] ...");
+			close(fd);
+			return;
+		}
+		CU_TEST(read(fd, buf, st.st_size) == st.st_size);
+	}
 	CU_TEST(tep_load_btf(test_tep, buf, st.st_size) == 0);
 
-	munmap(buf, st.st_size);
+	if (malloced) {
+		free(buf);
+	} else {
+		munmap(buf, st.st_size);
+	}
 	close(fd);
 
 	trace_seq_init(s);
-- 
2.53.0