Commit e3389458 authored by Artem Savkov's avatar Artem Savkov Committed by Alexei Starovoitov
Browse files

selftests/bpf: add destructive kfunc test 



Add a test checking that programs calling destructive kfuncs can only do
so if they have CAP_SYS_BOOT capabilities.

Signed-off-by: default avatarArtem Savkov <asavkov@redhat.com>
Link: https://lore.kernel.org/r/20220810065905.475418-4-asavkov@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 13379059

net/bpf/test_run.c

+5 −0
Original line number Diff line number Diff line
@@ -695,6 +695,10 @@ noinline void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p) 
{

}



noinline void bpf_kfunc_call_test_destructive(void)

{

}



__diag_pop();



ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO);
@@ -719,6 +723,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1) 
BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1)

BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2)

BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS)

BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE)

BTF_SET8_END(test_sk_check_kfunc_ids)



static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size,

tools/testing/selftests/bpf/prog_tests/kfunc_call.c

+36 −0
Original line number Diff line number Diff line
@@ -5,6 +5,9 @@ 
#include "kfunc_call_test.lskel.h"

#include "kfunc_call_test_subprog.skel.h"

#include "kfunc_call_test_subprog.lskel.h"

#include "kfunc_call_destructive.skel.h"



#include "cap_helpers.h"



static void test_main(void)

{
@@ -86,6 +89,36 @@ static void test_subprog_lskel(void) 
	kfunc_call_test_subprog_lskel__destroy(skel);

}



static int test_destructive_open_and_load(void)

{

	struct kfunc_call_destructive *skel;

	int err;



	skel = kfunc_call_destructive__open();

	if (!ASSERT_OK_PTR(skel, "prog_open"))

		return -1;



	err = kfunc_call_destructive__load(skel);



	kfunc_call_destructive__destroy(skel);



	return err;

}



static void test_destructive(void)

{

	__u64 save_caps = 0;



	ASSERT_OK(test_destructive_open_and_load(), "succesful_load");



	if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))

		return;



	ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");



	cap_enable_effective(save_caps, NULL);

}



void test_kfunc_call(void)

{

	if (test__start_subtest("main"))
@@ -96,4 +129,7 @@ void test_kfunc_call(void) 


	if (test__start_subtest("subprog_lskel"))

		test_subprog_lskel();



	if (test__start_subtest("destructive"))

		test_destructive();

}

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

0 → 100644
+14 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <vmlinux.h>

#include <bpf/bpf_helpers.h>



extern void bpf_kfunc_call_test_destructive(void) __ksym;



SEC("tc")

int kfunc_destructive_test(void)

{

	bpf_kfunc_call_test_destructive();

	return 0;

}



char _license[] SEC("license") = "GPL";