Commit 1ce33b6c authored by Daniel Rosenberg's avatar Daniel Rosenberg Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test allowing NULL buffer in dynptr slice 



bpf_dynptr_slice(_rw) no longer requires a buffer for verification. If the
buffer is needed, but not present, the function will return NULL.

Signed-off-by: default avatarDaniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-3-drosen@google.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 3bda08b6

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

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ static struct { 
	{"test_dynptr_is_null", SETUP_SYSCALL_SLEEP},

	{"test_dynptr_is_rdonly", SETUP_SKB_PROG},

	{"test_dynptr_clone", SETUP_SKB_PROG},

	{"test_dynptr_skb_no_buff", SETUP_SKB_PROG},

};



static void verify_success(const char *prog_name, enum test_setup_type setup_type)

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

+17 −0
Original line number Diff line number Diff line
@@ -505,3 +505,20 @@ int test_dynptr_clone(struct __sk_buff *skb) 


	return 0;

}



SEC("?cgroup_skb/egress")

int test_dynptr_skb_no_buff(struct __sk_buff *skb)

{

	struct bpf_dynptr ptr;

	__u64 *data;



	if (bpf_dynptr_from_skb(skb, 0, &ptr)) {

		err = 1;

		return 1;

	}



	/* This may return NULL. SKB may require a buffer */

	data = bpf_dynptr_slice(&ptr, 0, NULL, 1);



	return !!data;

}