Add a few reg_bounds selftests to test 32/16/8-bit ldsx and subreg comparison.
Without the previous patch, all added tests will fail.
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/reg_bounds.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
index eb74363f9f70..0da4225749bd 100644
--- a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
+++ b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
@@ -433,6 +433,19 @@ static struct range range_refine(enum num_t x_t, struct range x, enum num_t y_t,
y_cast = range_cast(y_t, x_t, y);
+ /* If we know that
+ * - *x* is in the range of signed 32bit value, and
+ * - *y_cast* range is 32-bit signed non-negative
+ * then *x* range can be improved with *y_cast* such that *x* range
+ * is 32-bit signed non-negative. Otherwise, if the new range for *x*
+ * allows upper 32-bit * 0xffffffff then the eventual new range for
+ * *x* will be out of signed 32-bit range which violates the origin
+ * *x* range.
+ */
+ if (x_t == S64 && y_t == S32 && y_cast.a <= S32_MAX && y_cast.b <= S32_MAX &&
+ (s64)x.a >= S32_MIN && (s64)x.b <= S32_MAX)
+ return range_improve(x_t, x, y_cast);
+
/* the case when new range knowledge, *y*, is a 32-bit subregister
* range, while previous range knowledge, *x*, is a full register
* 64-bit range, needs special treatment to take into account upper 32
@@ -2108,6 +2121,9 @@ static struct subtest_case crafted_cases[] = {
{S32, U32, {(u32)S32_MIN, 0}, {0, 0}},
{S32, U32, {(u32)S32_MIN, 0}, {(u32)S32_MIN, (u32)S32_MIN}},
{S32, U32, {(u32)S32_MIN, S32_MAX}, {S32_MAX, S32_MAX}},
+ {S64, U32, {0x0, 0x1f}, {0xffffffff80000000ULL, 0x000000007fffffffULL}},
+ {S64, U32, {0x0, 0x1f}, {0xffffffffffff8000ULL, 0x0000000000007fffULL}},
+ {S64, U32, {0x0, 0x1f}, {0xffffffffffffff80ULL, 0x000000000000007fULL}},
};
/* Go over crafted hard-coded cases. This is fast, so we do it as part of
--
2.43.0
