Commit 33772ff3 authored by Hao Sun's avatar Hao Sun Committed by Daniel Borkmann
Browse files

selftests/bpf: Add test for alu on PTR_TO_FLOW_KEYS 



Add a test case for PTR_TO_FLOW_KEYS alu. Testing if alu with variable
offset on flow_keys is rejected. For the fixed offset success case, we
already have C code coverage to verify (e.g. via bpf_flow.c).

Signed-off-by: default avatarHao Sun <sunhao.th@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240115082028.9992-2-sunhao.th@gmail.com
parent 22c7fa17

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

+19 −0
Original line number Diff line number Diff line
@@ -146,4 +146,23 @@ l0_%=: exit; \ 
	: __clobber_all);

}



SEC("flow_dissector")

__description("flow_keys illegal alu op with variable offset")

__failure __msg("R7 pointer arithmetic on flow_keys prohibited")

__naked void flow_keys_illegal_variable_offset_alu(void)

{

	asm volatile("					\

	r6 = r1;					\

	r7 = *(u64*)(r6 + %[flow_keys_off]);		\

	r8 = 8;						\

	r8 /= 1;					\

	r8 &= 8;					\

	r7 += r8;					\

	r0 = *(u64*)(r7 + 0);				\

	exit;						\

"	:

	: __imm_const(flow_keys_off, offsetof(struct __sk_buff, flow_keys))

	: __clobber_all);

}



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