diff mbox series

[bpf-next,v5,3/3] selftests/bpf: Skip callback tests if jit is disabled in test_verifier

Message ID 20240117111000.12763-4-yangtiezhu@loongson.cn
State New
Headers
Series Skip callback tests if jit is disabled in test_verifier |

Commit Message

Tiezhu Yang Jan. 17, 2024, 11:10 a.m. UTC 
  If CONFIG_BPF_JIT_ALWAYS_ON is not set and bpf_jit_enable is 0, there
exist 6 failed tests.

  [root@linux bpf]# echo 0 > /proc/sys/net/core/bpf_jit_enable
  [root@linux bpf]# echo 0 > /proc/sys/kernel/unprivileged_bpf_disabled
  [root@linux bpf]# ./test_verifier | grep FAIL
  #106/p inline simple bpf_loop call FAIL
  #107/p don't inline bpf_loop call, flags non-zero FAIL
  #108/p don't inline bpf_loop call, callback non-constant FAIL
  #109/p bpf_loop_inline and a dead func FAIL
  #110/p bpf_loop_inline stack locations for loop vars FAIL
  #111/p inline bpf_loop call in a big program FAIL
  Summary: 768 PASSED, 15 SKIPPED, 6 FAILED

The test log shows that callbacks are not allowed in non-JITed programs,
interpreter doesn't support them yet, thus these tests should be skipped
if jit is disabled, just handle this case in do_test_single().

After including bpf/libbpf_internal.h, there exist some build errors:

  error: attempt to use poisoned "u32"
  error: attempt to use poisoned "u64"

replace u32 and u64 with __u32 and __u64 to fix them.

With this patch:

  [root@linux bpf]# echo 0 > /proc/sys/net/core/bpf_jit_enable
  [root@linux bpf]# echo 0 > /proc/sys/kernel/unprivileged_bpf_disabled
  [root@linux bpf]# ./test_verifier | grep FAIL
  Summary: 768 PASSED, 21 SKIPPED, 0 FAILED

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Hou Tao <houtao1@huawei.com>
---
 tools/testing/selftests/bpf/test_verifier.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

Comments

Song Liu Jan. 17, 2024, 5:20 p.m. UTC | #1 
On Wed, Jan 17, 2024 at 3:10 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
[...]
> @@ -1622,6 +1624,16 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
>         alignment_prevented_execution = 0;
>
>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
> +               if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
> +                       for (i = 0; i < prog_len; i++, prog++) {
> +                               if (!insn_is_pseudo_func(prog))
> +                                       continue;
> +                               printf("SKIP (callbacks are not allowed in non-JITed programs)\n");
> +                               skips++;
> +                               goto close_fds;
> +                       }
> +               }
> +

I would put this chunk above "alignment_prevented_execution = 0;".

@@ -1619,6 +1621,16 @@ static void do_test_single(struct bpf_test
*test, bool unpriv,
                goto close_fds;
        }

+       if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
+               for (i = 0; i < prog_len; i++, prog++) {
+                       if (!insn_is_pseudo_func(prog))
+                               continue;
+                       printf("SKIP (callbacks are not allowed in
non-JITed programs)\n");
+                       skips++;
+                       goto close_fds;
+               }
+       }
+
        alignment_prevented_execution = 0;

        if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {

Other than this,

Acked-by: Song Liu <song@kernel.org>

Thanks,
Song
Hou Tao Jan. 18, 2024, 1:11 a.m. UTC | #2 
Hi Song,

On 1/18/2024 1:20 AM, Song Liu wrote:
> On Wed, Jan 17, 2024 at 3:10 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
> [...]
>> @@ -1622,6 +1624,16 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
>>         alignment_prevented_execution = 0;
>>
>>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
>> +               if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
>> +                       for (i = 0; i < prog_len; i++, prog++) {
>> +                               if (!insn_is_pseudo_func(prog))
>> +                                       continue;
>> +                               printf("SKIP (callbacks are not allowed in non-JITed programs)\n");
>> +                               skips++;
>> +                               goto close_fds;
>> +                       }
>> +               }
>> +
> I would put this chunk above "alignment_prevented_execution = 0;".
>
> @@ -1619,6 +1621,16 @@ static void do_test_single(struct bpf_test
> *test, bool unpriv,
>                 goto close_fds;
>         }
>
> +       if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
> +               for (i = 0; i < prog_len; i++, prog++) {
> +                       if (!insn_is_pseudo_func(prog))
> +                               continue;
> +                       printf("SKIP (callbacks are not allowed in
> non-JITed programs)\n");
> +                       skips++;
> +                       goto close_fds;
> +               }
> +       }
> +
>         alignment_prevented_execution = 0;
>
>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
>
> Other than this,

The check was placed before the checking of expected_ret in v3. However
I suggested Tiezhu to move it after the checking of expected_ret due to
the following two reasons:
1) when the expected result is REJECT, the return value in about one
third of these test cases is -EINVAL. And I think we should not waste
the cpu to check the pseudo func and exit prematurely, instead we should
let test_verifier check expected_err.
2) As for now all expected_ret of these failed cases are ACCEPT when jit
is disabled, so I think it will be enough for current situation and we
can revise it later if the checking of pseudo func is too later.

So wdyt ?

>
> Acked-by: Song Liu <song@kernel.org>
>
> Thanks,
> Song
>
> .
Song Liu Jan. 18, 2024, 1:27 a.m. UTC | #3 
Hi,

On Wed, Jan 17, 2024 at 5:11 PM Hou Tao <houtao@huaweicloud.com> wrote:
>
> Hi Song,
>
> On 1/18/2024 1:20 AM, Song Liu wrote:
> > On Wed, Jan 17, 2024 at 3:10 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
> > [...]
> >> @@ -1622,6 +1624,16 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
> >>         alignment_prevented_execution = 0;
> >>
> >>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
> >> +               if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
> >> +                       for (i = 0; i < prog_len; i++, prog++) {
> >> +                               if (!insn_is_pseudo_func(prog))
> >> +                                       continue;
> >> +                               printf("SKIP (callbacks are not allowed in non-JITed programs)\n");
> >> +                               skips++;
> >> +                               goto close_fds;
> >> +                       }
> >> +               }
> >> +
> > I would put this chunk above "alignment_prevented_execution = 0;".
> >
> > @@ -1619,6 +1621,16 @@ static void do_test_single(struct bpf_test
> > *test, bool unpriv,
> >                 goto close_fds;
> >         }
> >
> > +       if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
> > +               for (i = 0; i < prog_len; i++, prog++) {
> > +                       if (!insn_is_pseudo_func(prog))
> > +                               continue;
> > +                       printf("SKIP (callbacks are not allowed in
> > non-JITed programs)\n");
> > +                       skips++;
> > +                       goto close_fds;
> > +               }
> > +       }
> > +
> >         alignment_prevented_execution = 0;
> >
> >         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
> >
> > Other than this,
>
> The check was placed before the checking of expected_ret in v3. However
> I suggested Tiezhu to move it after the checking of expected_ret due to

I missed this part while reading the history of the set.

> the following two reasons:
> 1) when the expected result is REJECT, the return value in about one
> third of these test cases is -EINVAL. And I think we should not waste
> the cpu to check the pseudo func and exit prematurely, instead we should
> let test_verifier check expected_err.

I was thinking jit_disabled is not a common use case so that it is OK for
this path to be a little expensive.

> 2) As for now all expected_ret of these failed cases are ACCEPT when jit
> is disabled, so I think it will be enough for current situation and we
> can revise it later if the checking of pseudo func is too later.

That said, I won't object if we ship this version as-is.

Thanks,
Song
Hou Tao Jan. 18, 2024, 1:32 a.m. UTC | #4 
Hi,

On 1/18/2024 9:27 AM, Song Liu wrote:
> Hi,
>
> On Wed, Jan 17, 2024 at 5:11 PM Hou Tao <houtao@huaweicloud.com> wrote:
>> Hi Song,
>>
>> On 1/18/2024 1:20 AM, Song Liu wrote:
>>> On Wed, Jan 17, 2024 at 3:10 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>>> [...]
>>>> @@ -1622,6 +1624,16 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
>>>>         alignment_prevented_execution = 0;
>>>>
>>>>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
>>>> +               if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
>>>> +                       for (i = 0; i < prog_len; i++, prog++) {
>>>> +                               if (!insn_is_pseudo_func(prog))
>>>> +                                       continue;
>>>> +                               printf("SKIP (callbacks are not allowed in non-JITed programs)\n");
>>>> +                               skips++;
>>>> +                               goto close_fds;
>>>> +                       }
>>>> +               }
>>>> +
>>> I would put this chunk above "alignment_prevented_execution = 0;".
>>>
>>> @@ -1619,6 +1621,16 @@ static void do_test_single(struct bpf_test
>>> *test, bool unpriv,
>>>                 goto close_fds;
>>>         }
>>>
>>> +       if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
>>> +               for (i = 0; i < prog_len; i++, prog++) {
>>> +                       if (!insn_is_pseudo_func(prog))
>>> +                               continue;
>>> +                       printf("SKIP (callbacks are not allowed in
>>> non-JITed programs)\n");
>>> +                       skips++;
>>> +                       goto close_fds;
>>> +               }
>>> +       }
>>> +
>>>         alignment_prevented_execution = 0;
>>>
>>>         if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
>>>
>>> Other than this,
>> The check was placed before the checking of expected_ret in v3. However
>> I suggested Tiezhu to move it after the checking of expected_ret due to
> I missed this part while reading the history of the set.
>
>> the following two reasons:
>> 1) when the expected result is REJECT, the return value in about one
>> third of these test cases is -EINVAL. And I think we should not waste
>> the cpu to check the pseudo func and exit prematurely, instead we should
>> let test_verifier check expected_err.
> I was thinking jit_disabled is not a common use case so that it is OK for
> this path to be a little expensive.
>
>> 2) As for now all expected_ret of these failed cases are ACCEPT when jit
>> is disabled, so I think it will be enough for current situation and we
>> can revise it later if the checking of pseudo func is too later.
> That said, I won't object if we ship this version as-is.

I see and thanks for the explanation.
> Thanks,
> Song
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 1a09fc34d093..c7f57b5b04a7 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -41,6 +41,7 @@ 
 #include "test_btf.h"
 #include "../../../include/linux/filter.h"
 #include "testing_helpers.h"
+#include "bpf/libbpf_internal.h"
 
 #ifndef ENOTSUPP
 #define ENOTSUPP 524
@@ -74,6 +75,7 @@ 
 		    1ULL << CAP_BPF)
 #define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled"
 static bool unpriv_disabled = false;
+static bool jit_disabled;
 static int skips;
 static bool verbose = false;
 static int verif_log_level = 0;
@@ -1143,8 +1145,8 @@  static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 		} while (*fixup_map_xskmap);
 	}
 	if (*fixup_map_stacktrace) {
-		map_fds[12] = create_map(BPF_MAP_TYPE_STACK_TRACE, sizeof(u32),
-					 sizeof(u64), 1);
+		map_fds[12] = create_map(BPF_MAP_TYPE_STACK_TRACE, sizeof(__u32),
+					 sizeof(__u64), 1);
 		do {
 			prog[*fixup_map_stacktrace].imm = map_fds[12];
 			fixup_map_stacktrace++;
@@ -1203,7 +1205,7 @@  static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 	}
 	if (*fixup_map_reuseport_array) {
 		map_fds[19] = __create_map(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
-					   sizeof(u32), sizeof(u64), 1, 0);
+					   sizeof(__u32), sizeof(__u64), 1, 0);
 		do {
 			prog[*fixup_map_reuseport_array].imm = map_fds[19];
 			fixup_map_reuseport_array++;
@@ -1622,6 +1624,16 @@  static void do_test_single(struct bpf_test *test, bool unpriv,
 	alignment_prevented_execution = 0;
 
 	if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
+		if (fd_prog < 0 && saved_errno == EINVAL && jit_disabled) {
+			for (i = 0; i < prog_len; i++, prog++) {
+				if (!insn_is_pseudo_func(prog))
+					continue;
+				printf("SKIP (callbacks are not allowed in non-JITed programs)\n");
+				skips++;
+				goto close_fds;
+			}
+		}
+
 		if (fd_prog < 0) {
 			printf("FAIL\nFailed to load prog '%s'!\n",
 			       strerror(saved_errno));
@@ -1844,6 +1856,8 @@  int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
+	jit_disabled = !is_jit_enabled();
+
 	/* Use libbpf 1.0 API mode */
 	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);