Commit 8b788d66 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add tests for KF_RCU_PROTECTED 



Add a couple of test cases to ensure RCU protection is kicked in
automatically, and the return type is as expected.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250917032755.4068726-3-memxor@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 1512231b

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

+46 −0
Original line number Diff line number Diff line
@@ -123,3 +123,49 @@ int iter_next_ptr_mem_not_trusted(const void *ctx) 
	bpf_iter_num_destroy(&num_it);

	return 0;

}



SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")

__failure __msg("kernel func bpf_kfunc_ret_rcu_test requires RCU critical section protection")

int iter_ret_rcu_test_protected(const void *ctx)

{

	struct task_struct *p;



	p = bpf_kfunc_ret_rcu_test();

	return p->pid;

}



SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")

__failure __msg("R1 type=rcu_ptr_or_null_ expected=")

int iter_ret_rcu_test_type(const void *ctx)

{

	struct task_struct *p;



	bpf_rcu_read_lock();

	p = bpf_kfunc_ret_rcu_test();

	bpf_this_cpu_ptr(p);

	bpf_rcu_read_unlock();

	return 0;

}



SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")

__failure __msg("kernel func bpf_kfunc_ret_rcu_test_nostruct requires RCU critical section protection")

int iter_ret_rcu_test_protected_nostruct(const void *ctx)

{

	void *p;



	p = bpf_kfunc_ret_rcu_test_nostruct(4);

	return *(int *)p;

}



SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")

__failure __msg("R1 type=rdonly_rcu_mem_or_null expected=")

int iter_ret_rcu_test_type_nostruct(const void *ctx)

{

	void *p;



	bpf_rcu_read_lock();

	p = bpf_kfunc_ret_rcu_test_nostruct(4);

	bpf_this_cpu_ptr(p);

	bpf_rcu_read_unlock();

	return 0;

}

tools/testing/selftests/bpf/test_kmods/bpf_testmod.c

+12 −0
Original line number Diff line number Diff line
@@ -218,6 +218,16 @@ __bpf_kfunc void bpf_kfunc_rcu_task_test(struct task_struct *ptr) 
{

}



__bpf_kfunc struct task_struct *bpf_kfunc_ret_rcu_test(void)

{

	return NULL;

}



__bpf_kfunc int *bpf_kfunc_ret_rcu_test_nostruct(int rdonly_buf_size)

{

	return NULL;

}



__bpf_kfunc struct bpf_testmod_ctx *

bpf_testmod_ctx_create(int *err)

{
@@ -623,6 +633,8 @@ BTF_ID_FLAGS(func, bpf_kfunc_trusted_vma_test, KF_TRUSTED_ARGS) 
BTF_ID_FLAGS(func, bpf_kfunc_trusted_task_test, KF_TRUSTED_ARGS)

BTF_ID_FLAGS(func, bpf_kfunc_trusted_num_test, KF_TRUSTED_ARGS)

BTF_ID_FLAGS(func, bpf_kfunc_rcu_task_test, KF_RCU)

BTF_ID_FLAGS(func, bpf_kfunc_ret_rcu_test, KF_RET_NULL | KF_RCU_PROTECTED)

BTF_ID_FLAGS(func, bpf_kfunc_ret_rcu_test_nostruct, KF_RET_NULL | KF_RCU_PROTECTED)

BTF_ID_FLAGS(func, bpf_testmod_ctx_create, KF_ACQUIRE | KF_RET_NULL)

BTF_ID_FLAGS(func, bpf_testmod_ctx_release, KF_RELEASE)

BTF_ID_FLAGS(func, bpf_testmod_ops3_call_test_1)

tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h

+2 −0
Original line number Diff line number Diff line
@@ -158,6 +158,8 @@ void bpf_kfunc_trusted_vma_test(struct vm_area_struct *ptr) __ksym; 
void bpf_kfunc_trusted_task_test(struct task_struct *ptr) __ksym;

void bpf_kfunc_trusted_num_test(int *ptr) __ksym;

void bpf_kfunc_rcu_task_test(struct task_struct *ptr) __ksym;

struct task_struct *bpf_kfunc_ret_rcu_test(void) __ksym;

int *bpf_kfunc_ret_rcu_test_nostruct(int rdonly_buf_size) __ksym;



int bpf_kfunc_multi_st_ops_test_1(struct st_ops_args *args, u32 id) __ksym;