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: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230807175726.672394-1-yonghong.song@linux.dev
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index 9568089..be6f69a 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -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")