[bpf-next,v5,3/4] selftests/bpf: activate the OP_NE logic in range_cond()

Commit Message

Menglong Dong Dec. 19, 2023, 1:47 p.m. UTC

The edge range checking for the registers is supported by the verifier
now, so we can activate the extended logic in
tools/testing/selftests/bpf/prog_tests/reg_bounds.c/range_cond() to test
such logic.

Besides, I added some cases to the "crafted_cases" array for this logic.
These cases are mainly used to test the edge of the src reg and dst reg.

All reg bounds testings has passed in the SLOW_TESTS mode:

$ export SLOW_TESTS=1 && ./test_progs -t reg_bounds -j
Summary: 65/18959832 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Menglong Dong <[e-mail]>
---
v5:
- add "{U32, U32, {0, U32_MAX}, {U32_MAX, U32_MAX}}"
v4:
- remove reduplicated s32 casting
v3:
- do some adjustment to the crafted cases that we added
v2:
- add some cases to the "crafted_cases"
---
 .../selftests/bpf/prog_tests/reg_bounds.c     | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

Comments

Andrii Nakryiko Dec. 19, 2023, 6:41 p.m. UTC | #1

On Tue, Dec 19, 2023 at 5:50 AM Menglong Dong <[e-mail]> wrote:
>
> The edge range checking for the registers is supported by the verifier
> now, so we can activate the extended logic in
> tools/testing/selftests/bpf/prog_tests/reg_bounds.c/range_cond() to test
> such logic.
>
> Besides, I added some cases to the "crafted_cases" array for this logic.
> These cases are mainly used to test the edge of the src reg and dst reg.
>
> All reg bounds testings has passed in the SLOW_TESTS mode:
>
> $ export SLOW_TESTS=1 && ./test_progs -t reg_bounds -j
> Summary: 65/18959832 PASSED, 0 SKIPPED, 0 FAILED
>

Thanks for running SLOW_TESTS=1 mode as well!

Acked-by: Andrii Nakryiko <[e-mail]>

> Signed-off-by: Menglong Dong <[e-mail]>
> ---
> v5:
> - add "{U32, U32, {0, U32_MAX}, {U32_MAX, U32_MAX}}"
> v4:
> - remove reduplicated s32 casting
> v3:
> - do some adjustment to the crafted cases that we added
> v2:
> - add some cases to the "crafted_cases"
> ---
>  .../selftests/bpf/prog_tests/reg_bounds.c     | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
> index 3bf4ddd720a8..820d0bcfc474 100644
> --- a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
> +++ b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
> @@ -590,12 +590,7 @@ static void range_cond(enum num_t t, struct range x, struct range y,
>                 *newy = range(t, max_t(t, x.a, y.a), min_t(t, x.b, y.b));
>                 break;
>         case OP_NE:
> -               /* generic case, can't derive more information */
> -               *newx = range(t, x.a, x.b);
> -               *newy = range(t, y.a, y.b);
> -               break;
> -
> -               /* below extended logic is not supported by verifier just yet */
> +               /* below logic is supported by the verifier now */
>                 if (x.a == x.b && x.a == y.a) {
>                         /* X is a constant matching left side of Y */
>                         *newx = range(t, x.a, x.b);
> @@ -2101,6 +2096,18 @@ static struct subtest_case crafted_cases[] = {
>         {S32, S64, {(u32)S32_MIN, (u32)(s32)-255}, {(u32)(s32)-2, 0}},
>         {S32, S64, {0, 1}, {(u32)S32_MIN, (u32)S32_MIN}},
>         {S32, U32, {(u32)S32_MIN, (u32)S32_MIN}, {(u32)S32_MIN, (u32)S32_MIN}},
> +
> +       /* edge overlap testings for BPF_NE */
> +       {U64, U64, {0, U64_MAX}, {U64_MAX, U64_MAX}},
> +       {U64, U64, {0, U64_MAX}, {0, 0}},
> +       {S64, U64, {S64_MIN, 0}, {S64_MIN, S64_MIN}},
> +       {S64, U64, {S64_MIN, 0}, {0, 0}},
> +       {S64, U64, {S64_MIN, S64_MAX}, {S64_MAX, S64_MAX}},
> +       {U32, U32, {0, U32_MAX}, {0, 0}},
> +       {U32, U32, {0, U32_MAX}, {U32_MAX, U32_MAX}},
> +       {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}},
>  };
>
>  /* Go over crafted hard-coded cases. This is fast, so we do it as part of
> --
> 2.39.2
>

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
index 3bf4ddd720a8..820d0bcfc474 100644
--- a/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
+++ b/tools/testing/selftests/bpf/prog_tests/reg_bounds.c
@@ -590,12 +590,7 @@  static void range_cond(enum num_t t, struct range x, struct range y,
 		*newy = range(t, max_t(t, x.a, y.a), min_t(t, x.b, y.b));
 		break;
 	case OP_NE:
-		/* generic case, can't derive more information */
-		*newx = range(t, x.a, x.b);
-		*newy = range(t, y.a, y.b);
-		break;
-
-		/* below extended logic is not supported by verifier just yet */
+		/* below logic is supported by the verifier now */
 		if (x.a == x.b && x.a == y.a) {
 			/* X is a constant matching left side of Y */
 			*newx = range(t, x.a, x.b);
@@ -2101,6 +2096,18 @@  static struct subtest_case crafted_cases[] = {
 	{S32, S64, {(u32)S32_MIN, (u32)(s32)-255}, {(u32)(s32)-2, 0}},
 	{S32, S64, {0, 1}, {(u32)S32_MIN, (u32)S32_MIN}},
 	{S32, U32, {(u32)S32_MIN, (u32)S32_MIN}, {(u32)S32_MIN, (u32)S32_MIN}},
+
+	/* edge overlap testings for BPF_NE */
+	{U64, U64, {0, U64_MAX}, {U64_MAX, U64_MAX}},
+	{U64, U64, {0, U64_MAX}, {0, 0}},
+	{S64, U64, {S64_MIN, 0}, {S64_MIN, S64_MIN}},
+	{S64, U64, {S64_MIN, 0}, {0, 0}},
+	{S64, U64, {S64_MIN, S64_MAX}, {S64_MAX, S64_MAX}},
+	{U32, U32, {0, U32_MAX}, {0, 0}},
+	{U32, U32, {0, U32_MAX}, {U32_MAX, U32_MAX}},
+	{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}},
 };
 
 /* Go over crafted hard-coded cases. This is fast, so we do it as part of