[ Upstream commit 0979ff7992fb6f4eb837995b12f4071dcafebd2d ]
Currently, ksym_search located at trace_helpers won't check symbols are
existing or not.
In ksym_search, when symbol is not found, it will return &syms[0](_stext).
But when the kernel symbols are not loaded, it will return NULL, which is
not a desired action.
This commit will add verification logic whether symbols are loaded prior
to the symbol search.
Signed-off-by: Daniel T. Lee <danieltimlee@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/bpf/trace_helpers.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 4cdb63bf0521d..9a9fc6c9b70b5 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -52,6 +52,10 @@ struct ksym *ksym_search(long key)
int start = 0, end = sym_cnt;
int result;
+ /* kallsyms not loaded. return NULL */
+ if (sym_cnt <= 0)
+ return NULL;
+
while (start < end) {
size_t mid = start + (end - start) / 2;
--
2.20.1
