On 03/15/2019 07:42 AM, Daniel T. Lee wrote:
> Since, ksym_search added with verification logic for symbols existence,
> it could return NULL when the kernel symbols are not loaded.
>
> This commit will add NULL check logic after ksym_search.
>
> Signed-off-by: Daniel T. Lee <danieltim...@gmail.com>
> ---
> samples/bpf/offwaketime_user.c | 5 +++++
> samples/bpf/sampleip_user.c | 5 +++++
> samples/bpf/trace_event_user.c | 5 +++++
> 3 files changed, 15 insertions(+)
This would also need fixing to check for NULL in:
tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
> diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
> index f06063af9fcb..52e29467a509 100644
> --- a/samples/bpf/offwaketime_user.c
> +++ b/samples/bpf/offwaketime_user.c
> @@ -28,6 +28,11 @@ static void print_ksym(__u64 addr)
> if (!addr)
> return;
> sym = ksym_search(addr);
> + if (!sym){
> + printf("ksym not found. Is kallsyms loaded?\n");
> + return;
> + }
> +
> if (PRINT_RAW_ADDR)
> printf("%s/%llx;", sym->name, addr);
> else
> diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
> index 216c7ecbbbe9..23b90a45c802 100644
> --- a/samples/bpf/sampleip_user.c
> +++ b/samples/bpf/sampleip_user.c
> @@ -109,6 +109,11 @@ static void print_ip_map(int fd)
> for (i = 0; i < max; i++) {
> if (counts[i].ip > PAGE_OFFSET) {
> sym = ksym_search(counts[i].ip);
> + if (!sym) {
> + printf("ksym not found. Is kallsyms loaded?\n");
> + continue;
> + }
> +
> printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
> counts[i].count);
> } else {
> diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
> index d08046ab81f0..bc8e6afdae6d 100644
> --- a/samples/bpf/trace_event_user.c
> +++ b/samples/bpf/trace_event_user.c
> @@ -34,6 +34,11 @@ static void print_ksym(__u64 addr)
> if (!addr)
> return;
> sym = ksym_search(addr);
> + if (!sym){
> + printf("ksym not found. Is kallsyms loaded?\n");
> + return;
> + }
> +
> printf("%s;", sym->name);
> if (!strcmp(sym->name, "sys_read"))
> sys_read_seen = true;
>
