Commit f25fd608 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Martin KaFai Lau
Browse files

selftests/bpf: Add various tests to check helper access into ptr_to_btf_id. 



Add various tests to check helper access into ptr_to_btf_id.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDavid Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230313235845.61029-4-alexei.starovoitov@gmail.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 3e30be42

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

+36 −0
Original line number Diff line number Diff line
@@ -301,3 +301,39 @@ int BPF_PROG(task_kfunc_from_lsm_task_free, struct task_struct *task) 
	bpf_task_release(acquired);

	return 0;

}



SEC("tp_btf/task_newtask")

__failure __msg("access beyond the end of member comm")

int BPF_PROG(task_access_comm1, struct task_struct *task, u64 clone_flags)

{

	bpf_strncmp(task->comm, 17, "foo");

	return 0;

}



SEC("tp_btf/task_newtask")

__failure __msg("access beyond the end of member comm")

int BPF_PROG(task_access_comm2, struct task_struct *task, u64 clone_flags)

{

	bpf_strncmp(task->comm + 1, 16, "foo");

	return 0;

}



SEC("tp_btf/task_newtask")

__failure __msg("write into memory")

int BPF_PROG(task_access_comm3, struct task_struct *task, u64 clone_flags)

{

	bpf_probe_read_kernel(task->comm, 16, task->comm);

	return 0;

}



SEC("fentry/__set_task_comm")

__failure __msg("R1 type=ptr_ expected")

int BPF_PROG(task_access_comm4, struct task_struct *task, const char *buf, bool exec)

{

	/*

	 * task->comm is a legacy ptr_to_btf_id. The verifier cannot guarantee

	 * its safety. Hence it cannot be accessed with normal load insns.

	 */

	bpf_strncmp(task->comm, 16, "foo");

	return 0;

}

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

+4 −0
Original line number Diff line number Diff line
@@ -207,6 +207,10 @@ int BPF_PROG(test_task_from_pid_invalid, struct task_struct *task, u64 clone_fla 
	if (!is_test_kfunc_task())

		return 0;



	bpf_strncmp(task->comm, 12, "foo");

	bpf_strncmp(task->comm, 16, "foo");

	bpf_strncmp(&task->comm[8], 4, "foo");



	if (is_pid_lookup_valid(-1)) {

		err = 1;

		return 0;