Commit 838bd4ac authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

selftests/bpf: Add a test case for kptr_rcu. 



Tweak existing map_kptr test to check kptr_rcu.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarDavid Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-5-alexei.starovoitov@gmail.com
parent 20c09d92

tools/testing/selftests/bpf/progs/map_kptr.c

+12 −0
Original line number Diff line number Diff line
@@ -118,6 +118,7 @@ extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp 
extern struct prog_test_ref_kfunc *

bpf_kfunc_call_test_kptr_get(struct prog_test_ref_kfunc **p, int a, int b) __ksym;

extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;

void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p) __ksym;



#define WRITE_ONCE(x, val) ((*(volatile typeof(x) *) &(x)) = (val))
@@ -147,12 +148,23 @@ static void test_kptr_ref(struct map_value *v) 
	WRITE_ONCE(v->unref_ptr, p);

	if (!p)

		return;

	/*

	 * p is rcu_ptr_prog_test_ref_kfunc,

	 * because bpf prog is non-sleepable and runs in RCU CS.

	 * p can be passed to kfunc that requires KF_RCU.

	 */

	bpf_kfunc_call_test_ref(p);

	if (p->a + p->b > 100)

		return;

	/* store NULL */

	p = bpf_kptr_xchg(&v->ref_ptr, NULL);

	if (!p)

		return;

	/*

	 * p is trusted_ptr_prog_test_ref_kfunc.

	 * p can be passed to kfunc that requires KF_RCU.

	 */

	bpf_kfunc_call_test_ref(p);

	if (p->a + p->b > 100) {

		bpf_kfunc_call_test_release(p);

		return;