Add test that checks whether unsigned ranges deduced by the verifier for
sign extension instruction is correct. Without previous patch that
fixes truncation in coerce_reg_to_size_sx() this test fails.
Acked-by: Shung-Hsi Yu <shung-hsi.yu@xxxxxxxx>
Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@xxxxxxxxxxxxxx>
---
.../selftests/bpf/progs/verifier_movsx.c | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index 028ec855587b..0cb879c609c5 100644
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -287,6 +287,26 @@ l0_%=: \
: __clobber_all);
}
+SEC("socket")
+__description("MOV64SX, S8, unsigned range_check")
+__success __retval(0)
+__naked void mov64sx_s8_range_check(void)
+{
+ asm volatile (" \
+ call %[bpf_get_prandom_u32]; \
+ r0 &= 0x1; \
+ r0 += 0xfe; \
+ r0 = (s8)r0; \
+ if r0 < 0xfffffffffffffffe goto label_%=; \
+ r0 = 0; \
+ exit; \
+label_%=: \
+ exit; \
+" :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
#else
SEC("socket")
--
2.43.0
