[ 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@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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;