Commit a62293c3 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add a few tests to cover 



Add three unit tests in verifier_movsx.c to cover
cases where missed var_off setting can cause
unexpected verification success or failure.

Signed-off-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240615174637.3995589-1-yonghong.song@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 44b7f715

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

+63 −0
Original line number Diff line number Diff line
@@ -224,6 +224,69 @@ l0_%=: \ 
	: __clobber_all);

}



SEC("socket")

__description("MOV32SX, S8, var_off u32_max")

__failure __msg("infinite loop detected")

__failure_unpriv __msg_unpriv("back-edge from insn 2 to 0")

__naked void mov64sx_s32_varoff_1(void)

{

	asm volatile ("					\

l0_%=:							\

	r3 = *(u8 *)(r10 -387);				\

	w7 = (s8)w3;					\

	if w7 >= 0x2533823b goto l0_%=;			\

	w0 = 0;						\

	exit;						\

"	:

	:

	: __clobber_all);

}



SEC("socket")

__description("MOV32SX, S8, var_off not u32_max, positive after s8 extension")

__success __retval(0)

__failure_unpriv __msg_unpriv("frame pointer is read only")

__naked void mov64sx_s32_varoff_2(void)

{

	asm volatile ("					\

	call %[bpf_get_prandom_u32];			\

	r3 = r0;					\

	r3 &= 0xf;					\

	w7 = (s8)w3;					\

	if w7 s>= 16 goto l0_%=;			\

	w0 = 0;						\

	exit;						\

l0_%=:							\

	r10 = 1;					\

	exit;						\

"	:

	: __imm(bpf_get_prandom_u32)

	: __clobber_all);

}



SEC("socket")

__description("MOV32SX, S8, var_off not u32_max, negative after s8 extension")

__success __retval(0)

__failure_unpriv __msg_unpriv("frame pointer is read only")

__naked void mov64sx_s32_varoff_3(void)

{

	asm volatile ("					\

	call %[bpf_get_prandom_u32];			\

	r3 = r0;					\

	r3 &= 0xf;					\

	r3 |= 0x80;					\

	w7 = (s8)w3;					\

	if w7 s>= -5 goto l0_%=;			\

	w0 = 0;						\

	exit;						\

l0_%=:							\

	r10 = 1;					\

	exit;						\

"	:

	: __imm(bpf_get_prandom_u32)

	: __clobber_all);

}



#else



SEC("socket")