Compiling kernel and selftests/bpf with latest llvm like blow:
make -j LLVM=1
make -C tools/testing/selftests/bpf -j LLVM=1
I hit the following compilation error:
/.../prog_tests/log_buf.c:215:6: error: variable 'log_buf' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (!ASSERT_OK_PTR(raw_btf_data, "raw_btf_data_good"))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../prog_tests/log_buf.c:264:7: note: uninitialized use occurs here
free(log_buf);
^~~~~~~
/.../prog_tests/log_buf.c:215:2: note: remove the 'if' if its condition is always false
if (!ASSERT_OK_PTR(raw_btf_data, "raw_btf_data_good"))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../prog_tests/log_buf.c:205:15: note: initialize the variable 'log_buf' to silence this warning
char *log_buf;
^
= NULL
1 error generated.
Compiler rightfully detected that log_buf is uninitialized in one of failure path as indicated
in the above.
Proper initialization of 'log_buf' variable fixed the issue.
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
tools/testing/selftests/bpf/prog_tests/log_buf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/log_buf.c b/tools/testing/selftests/bpf/prog_tests/log_buf.c
index e469b023962b..1ef377a7e731 100644
--- a/tools/testing/selftests/bpf/prog_tests/log_buf.c
+++ b/tools/testing/selftests/bpf/prog_tests/log_buf.c
@@ -202,7 +202,7 @@ static void bpf_btf_load_log_buf(void)
const void *raw_btf_data;
__u32 raw_btf_size;
struct btf *btf;
- char *log_buf;
+ char *log_buf = NULL;
int fd = -1;
btf = btf__new_empty();
--
2.30.2
