This commit adds a few more tests related to tnum_scast that explicitly
check cases with known / unknown sign bit, as well as values that cross
zero (going from negative to positive).
Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@xxxxxxxxxxxxxx>
---
.../selftests/bpf/progs/verifier_movsx.c | 73 +++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_movsx.c b/tools/testing/selftests/bpf/progs/verifier_movsx.c
index 994bbc346d25..20abeec09dee 100644
--- a/tools/testing/selftests/bpf/progs/verifier_movsx.c
+++ b/tools/testing/selftests/bpf/progs/verifier_movsx.c
@@ -327,6 +327,79 @@ label_%=: \
: __clobber_all);
}
+SEC("socket")
+__description("MOV64SX, S8, unknown value")
+__success __success_unpriv __retval(1)
+__naked void mov64sx_s8_unknown(void)
+{
+ asm volatile (" \
+ call %[bpf_get_prandom_u32]; \
+ r1 = r0; \
+ r1 &= 0xFF; \
+ r1 = (s8)r1; \
+ if r1 s>= -128 goto l0_%=; \
+ r0 = 0; \
+ exit; \
+l0_%=: \
+ if r1 s<= 127 goto l1_%=; \
+ r0 = 0; \
+ exit; \
+l1_%=: \
+ r0 = 1; \
+ exit; \
+" :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
+SEC("socket")
+ __description("MOV64SX, S8, sign bit unknown")
+ __success __success_unpriv __retval(1)
+__naked void mov64sx_s8_sign_unknown(void)
+{
+ asm volatile (" \
+ call %[bpf_get_prandom_u32]; \
+ r1 = r0; \
+ r1 &= 0x7F; \
+ r1 |= 0x80; \
+ r1 = (s8)r1; \
+ if r1 s>= -128 goto l0_%=; \
+ r0 = 0; \
+ exit; \
+l0_%=: \
+ if r1 s<= 127 goto l1_%=; \
+ r0 = 0; \
+ exit; \
+l1_%=: \
+ r0 = 1; \
+ exit; \
+ " :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
+SEC("socket")
+ __description("MOV64SX, S8, value crossing zero")
+ __success __success_unpriv __retval(1)
+__naked void mov64sx_s8_cross_zero(void)
+{
+ asm volatile (" \
+ call %[bpf_get_prandom_u32]; \
+ r1 = r0; \
+ r1 &= 0xFF; \
+ r1 = (s8)r1; \
+ if r1 s> -10 goto l0_%=; \
+ if r1 s< 10 goto l0_%=; \
+ r0 = 0; \
+ exit; \
+l0_%=: \
+ r0 = 1; \
+ exit; \
+ " :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all);
+}
+
#else
SEC("socket")
--
2.43.0
