From: Alexei Starovoitov <ast@kernel.org>

Add tests for special arithmetic shift right.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 .../selftests/bpf/progs/verifier_subreg.c     | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/verifier_subreg.c b/tools/testing/selftests/bpf/progs/verifier_subreg.c
index 8613ea160dcd..b18b75c532bc 100644
--- a/tools/testing/selftests/bpf/progs/verifier_subreg.c
+++ b/tools/testing/selftests/bpf/progs/verifier_subreg.c
@@ -670,4 +670,45 @@ __naked void ldx_w_zero_extend_check(void)
 	: __clobber_all);
 }
 
+SEC("socket")
+__description("s>>=31")
+__success __success_unpriv __retval(0)
+__naked void arsh_31(void)
+{
+	asm volatile ("					\
+	call %[bpf_get_prandom_u32];			\
+	w2 = w0;					\
+	w2 s>>= 31;					\
+	w2 &= -134;					\
+	if w2 s> -1 goto +2;				\
+	if w2 != 0xffffff78 goto +1;			\
+	w0 /= 0;					\
+	w0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_get_prandom_u32)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("s>>=63")
+__success __success_unpriv __retval(0)
+__naked void arsh_63(void)
+{
+	asm volatile ("					\
+	call %[bpf_get_prandom_u32];			\
+	r2 = r0;					\
+	r2 <<= 32;					\
+	r2 s>>= 63;					\
+	r2 &= -134;					\
+	if r2 s> -1 goto +2;				\
+	if r2 != 0xffffff78 goto +1;			\
+	r0 /= 0;					\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_get_prandom_u32)
+	: __clobber_all);
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.47.3