diff mbox series

selftests/clone3: Skip new time namespace test when unsupported

Message ID 20231020-kselftest-clone3-time-ns-v1-1-31a17e072a05@kernel.org
State New
Headers show
Series selftests/clone3: Skip new time namespace test when unsupported | expand

Commit Message

Mark Brown Oct. 19, 2023, 11:08 p.m. UTC
Use a filter function to skip the time namespace test on systems with
!CONFIG_TIME_NS. This reworks a fix originally done by Tiezhu Yang prior
to the refactoring in 34dce23f7e40 ("selftests/clone3: Report descriptive
test names"). The changelog from their fix explains the issue very clearly:

When execute the following command to test clone3 under !CONFIG_TIME_NS:

  # make headers && cd tools/testing/selftests/clone3 && make && ./clone3

we can see the following error info:

  # [7538] Trying clone3() with flags 0x80 (size 0)
  # Invalid argument - Failed to create new process
  # [7538] clone3() with flags says: -22 expected 0
  not ok 18 [7538] Result (-22) is different than expected (0)
  ...
  # Totals: pass:18 fail:1 xfail:0 xpass:0 skip:0 error:0

This is because if CONFIG_TIME_NS is not set, but the flag
CLONE_NEWTIME (0x80) is used to clone a time namespace, it
will return -EINVAL in copy_time_ns().

If kernel does not support CONFIG_TIME_NS, /proc/self/ns/time
will be not exist, and then we should skip clone3() test with
CLONE_NEWTIME.

With this patch under !CONFIG_TIME_NS:

  # make headers && cd tools/testing/selftests/clone3 && make && ./clone3
  ...
  # Time namespaces are not supported
  ok 18 # SKIP Skipping clone3() with CLONE_NEWTIME
  ...
  # Totals: pass:18 fail:0 xfail:0 xpass:0 skip:1 error:0

Fixes: 515bddf0ec41 ("selftests/clone3: test clone3 with CLONE_NEWTIME")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Original-fix-from: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/clone3/clone3.c | 11 +++++++++++
 1 file changed, 11 insertions(+)


---
base-commit: 8d4099dd0727acfc8b0f644eacaf852f9d5dc649
change-id: 20231019-kselftest-clone3-time-ns-730b6f4187c7

Best regards,

Comments

Andrew Morton Oct. 19, 2023, 11:35 p.m. UTC | #1
On Fri, 20 Oct 2023 00:08:12 +0100 Mark Brown <broonie@kernel.org> wrote:

> Use a filter function to skip the time namespace test on systems with
> !CONFIG_TIME_NS. This reworks a fix originally done by Tiezhu Yang prior
> to the refactoring in 34dce23f7e40 ("selftests/clone3: Report descriptive
> test names"). The changelog from their fix explains the issue very clearly:

I was about to send Tiezhu Yang's fix to Linus.   I'll rebase mm-hotfixes-stable
to drop that patch, so you own it now!

Please note that your version lacks an explicit cc:stable, but I suppose the
stablebots will scoop it up anyway.

> Original-fix-from: Tiezhu Yang <yangtiezhu@loongson.cn>

"Original-fix-from" isn't a thing.  In fact it seems to be the first
time this has been used.  Grepping for  "Original-.*:" shows
all sorts of innovations, including "Based-on-the-original-screenplay-by:".

I guess Documentation/process/submitting-patches.rst and checkpatch
lost this fight a long time ago.
Tiezhu Yang Oct. 20, 2023, 1:34 a.m. UTC | #2
On 10/20/2023 07:35 AM, Andrew Morton wrote:
> On Fri, 20 Oct 2023 00:08:12 +0100 Mark Brown <broonie@kernel.org> wrote:
>
>> Use a filter function to skip the time namespace test on systems with
>> !CONFIG_TIME_NS. This reworks a fix originally done by Tiezhu Yang prior
>> to the refactoring in 34dce23f7e40 ("selftests/clone3: Report descriptive
>> test names"). The changelog from their fix explains the issue very clearly:
>
> I was about to send Tiezhu Yang's fix to Linus.   I'll rebase mm-hotfixes-stable
> to drop that patch, so you own it now!
>
> Please note that your version lacks an explicit cc:stable, but I suppose the
> stablebots will scoop it up anyway.
>
>> Original-fix-from: Tiezhu Yang <yangtiezhu@loongson.cn>
>
> "Original-fix-from" isn't a thing.  In fact it seems to be the first
> time this has been used.  Grepping for  "Original-.*:" shows
> all sorts of innovations, including "Based-on-the-original-screenplay-by:".
>
> I guess Documentation/process/submitting-patches.rst and checkpatch
> lost this fight a long time ago.
>

Thank you all.

If it is possible, I think it is better to rebase linux-kselftest next
to do the following things sequentially.

(1) Apply patch "selftests/clone3: Fix broken test under !CONFIG_TIME_NS"
which is sent on 11 Jul 2023.

https://lore.kernel.org/linux-kselftest/1689066814-13295-1-git-send-email-yangtiezhu@loongson.cn/

(2) Squash the changes in patch "selftests/clone3: Skip new time 
namespace test when unsupported"

https://lore.kernel.org/linux-kselftest/20231020-kselftest-clone3-time-ns-v1-1-31a17e072a05@kernel.org/

into patch "selftests/clone3: Report descriptive test names", and then 
apply it.

https://lore.kernel.org/linux-kselftest/20231018-kselftest-clone3-output-v1-1-12b7c50ea2cf@kernel.org/

This can make the log more clear. Anyway, I am fine with either way.

Thanks,
Tiezhu
Mark Brown Oct. 20, 2023, 11:46 a.m. UTC | #3
On Thu, Oct 19, 2023 at 04:35:38PM -0700, Andrew Morton wrote:
> On Fri, 20 Oct 2023 00:08:12 +0100 Mark Brown <broonie@kernel.org> wrote:

> > Use a filter function to skip the time namespace test on systems with
> > !CONFIG_TIME_NS. This reworks a fix originally done by Tiezhu Yang prior
> > to the refactoring in 34dce23f7e40 ("selftests/clone3: Report descriptive
> > test names"). The changelog from their fix explains the issue very clearly:

> I was about to send Tiezhu Yang's fix to Linus.   I'll rebase mm-hotfixes-stable
> to drop that patch, so you own it now!

> Please note that your version lacks an explicit cc:stable, but I suppose the
> stablebots will scoop it up anyway.

I think I was expecting Tiezhu's version to still get sent and then the
two versions to get merged - the refactoring that caused the conflict is
very clearly not stable material.

> > Original-fix-from: Tiezhu Yang <yangtiezhu@loongson.cn>

> "Original-fix-from" isn't a thing.  In fact it seems to be the first
> time this has been used.  Grepping for  "Original-.*:" shows
> all sorts of innovations, including "Based-on-the-original-screenplay-by:".

> I guess Documentation/process/submitting-patches.rst and checkpatch
> lost this fight a long time ago.

Well, they've always been documenting existing practice.
diff mbox series

Patch

diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index 9429d361059e..915846bc32cc 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -138,6 +138,16 @@  static bool not_root(void)
 	return false;
 }
 
+static bool timens_unsupported(void)
+{
+	if (access("/proc/self/ns/time", F_OK) == 0) {
+		ksft_print_msg("Time namespaces are not supported\n");
+		return true;
+	}
+
+	return false;
+}
+
 static size_t page_size_plus_8(void)
 {
 	return getpagesize() + 8;
@@ -282,6 +292,7 @@  static const struct test tests[] = {
 		.size = 0,
 		.expected = 0,
 		.test_mode = CLONE3_ARGS_NO_TEST,
+		.filter = timens_unsupported,
 	},
 	{
 		.name = "exit signal (SIGCHLD) in flags",