For preemption-related kfuncs, we don't test their interaction with
sleepable kfuncs (we do test helpers) even though the verifier has
code to protect against such a pattern. Expand coverage of the selftest
to include this case.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
tools/testing/selftests/bpf/progs/preempt_lock.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/preempt_lock.c b/tools/testing/selftests/bpf/progs/preempt_lock.c
index 885377e83607..d24314c394c7 100644
--- a/tools/testing/selftests/bpf/progs/preempt_lock.c
+++ b/tools/testing/selftests/bpf/progs/preempt_lock.c
@@ -113,6 +113,18 @@ int preempt_sleepable_helper(void *ctx)
return 0;
}
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+__failure __msg("kernel func bpf_copy_from_user_str is sleepable within non-preemptible region")
+int preempt_sleepable_kfunc(void *ctx)
+{
+ u32 data;
+
+ bpf_preempt_disable();
+ bpf_copy_from_user_str(&data, sizeof(data), NULL, 0);
+ bpf_preempt_enable();
+ return 0;
+}
+
int __noinline preempt_global_subprog(void)
{
preempt_balance_subprog();
--
2.43.5
