Commit e2e70535 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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selftests/bpf: add more cases for __arg_trusted __arg_nullable args 



Add extra layer of global functions to ensure that passing around
(trusted) PTR_TO_BTF_ID_OR_NULL registers works as expected. We also
extend trusted_task_arg_nullable subtest to check three possible valid
argumements: known NULL, known non-NULL, and maybe NULL cases.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240202190529.2374377-3-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 8f13c340

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

+29 −3
Original line number Diff line number Diff line
@@ -19,15 +19,41 @@ __weak int subprog_trusted_task_nullable(struct task_struct *task __arg_trusted 
	return task->pid + task->tgid;

}



SEC("?kprobe")

__weak int subprog_trusted_task_nullable_extra_layer(struct task_struct *task __arg_trusted __arg_nullable)

{

	return subprog_trusted_task_nullable(task) + subprog_trusted_task_nullable(NULL);

}



SEC("?tp_btf/task_newtask")

__success __log_level(2)

__msg("Validating subprog_trusted_task_nullable() func#1...")

__msg(": R1=trusted_ptr_or_null_task_struct(")

int trusted_task_arg_nullable(void *ctx)

{

	struct task_struct *t = bpf_get_current_task_btf();

	struct task_struct *t1 = bpf_get_current_task_btf();

	struct task_struct *t2 = bpf_task_acquire(t1);

	int res = 0;



	/* known NULL */

	res += subprog_trusted_task_nullable(NULL);



	return subprog_trusted_task_nullable(t) + subprog_trusted_task_nullable(NULL);

	/* known non-NULL */

	res += subprog_trusted_task_nullable(t1);

	res += subprog_trusted_task_nullable_extra_layer(t1);



	/* unknown if NULL or not */

	res += subprog_trusted_task_nullable(t2);

	res += subprog_trusted_task_nullable_extra_layer(t2);



	if (t2) {

		/* known non-NULL after explicit NULL check, just in case */

		res += subprog_trusted_task_nullable(t2);

		res += subprog_trusted_task_nullable_extra_layer(t2);



		bpf_task_release(t2);

	}



	return res;

}



__weak int subprog_trusted_task_nonnull(struct task_struct *task __arg_trusted)