Commit a5c0a42b authored by Yonghong Song's avatar Yonghong Song Committed by Martin KaFai Lau
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selftests/bpf: Add a movsx selftest for sign-extension of R10 



A movsx selftest is added for sign-extension of frame pointer R10.
The verification fails for both privileged and unprivileged
prog runs.

Signed-off-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230807175726.672394-1-yonghong.song@linux.dev


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent db2baf82

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

+22 −0
Original line number Diff line number Diff line
@@ -198,6 +198,28 @@ l0_%=: \ 
	: __clobber_all);

}



SEC("socket")

__description("MOV64SX, S16, R10 Sign Extension")

__failure __msg("R1 type=scalar expected=fp, pkt, pkt_meta, map_key, map_value, mem, ringbuf_mem, buf, trusted_ptr_")

__failure_unpriv __msg_unpriv("R10 sign-extension part of pointer")

__naked void mov64sx_s16_r10(void)

{

	asm volatile ("					\

	r1 = 553656332;					\

	*(u32 *)(r10 - 8) = r1; 			\

	r1 = (s16)r10;					\

	r1 += -8;					\

	r2 = 3;						\

	if r2 <= r1 goto l0_%=;				\

l0_%=:							\

	call %[bpf_trace_printk];			\

	r0 = 0;						\

	exit;						\

"	:

	: __imm(bpf_trace_printk)

	: __clobber_all);

}



#else



SEC("socket")