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From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
	Shuah Khan <shuah@kernel.org>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Prakash Sangappa <prakash.sangappa@oracle.com>
Subject: Re: [PATCH 1/3] userfaultfd: selftest: Fix checking of userfaultfd_open() result
Date: Mon, 30 Jul 2018 20:53:30 -0300	[thread overview]
Message-ID: <8736w0b7r9.fsf@morokweng.localdomain> (raw)
In-Reply-To: <20180725135942.GC25188@rapoport-lnx>


Hello Mike,

Thanks for promptly reviewing the patches.

Mike Rapoport <rppt@linux.vnet.ibm.com> writes:

> Hi,
>
> On Tue, Jul 24, 2018 at 11:42:07PM -0300, Thiago Jung Bauermann wrote:
>> If the userfaultfd test is run on a kernel with CONFIG_USERFAULTFD=n, it
>> will report that the system call is not available yet go ahead and continue
>> anyway:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>   bounces: 0, mode:, register failure
>>
>> This is because userfaultfd_open() returns 0 on success and 1 on error but
>> all callers assume that it returns < 0 on error.
>>
>> Since the convention of the test as a whole is the one used by
>> userfault_open(), fix its callers instead. Now the test behaves correctly:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>
>> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
>
> It seems that this patch is superseded by the second patch in this series.

Yes, but since this is a simple bugfix while the other patch is a
proposed improvement which can be debated, I think it's worthwhile to
keep them separate.

--
Thiago Jung Bauermann
IBM Linux Technology Center


WARNING: multiple messages have this Message-ID (diff)
From: bauerman at linux.ibm.com (Thiago Jung Bauermann)
Subject: [PATCH 1/3] userfaultfd: selftest: Fix checking of userfaultfd_open() result
Date: Mon, 30 Jul 2018 20:53:30 -0300	[thread overview]
Message-ID: <8736w0b7r9.fsf@morokweng.localdomain> (raw)
In-Reply-To: <20180725135942.GC25188@rapoport-lnx>


Hello Mike,

Thanks for promptly reviewing the patches.

Mike Rapoport <rppt at linux.vnet.ibm.com> writes:

> Hi,
>
> On Tue, Jul 24, 2018 at 11:42:07PM -0300, Thiago Jung Bauermann wrote:
>> If the userfaultfd test is run on a kernel with CONFIG_USERFAULTFD=n, it
>> will report that the system call is not available yet go ahead and continue
>> anyway:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>   bounces: 0, mode:, register failure
>>
>> This is because userfaultfd_open() returns 0 on success and 1 on error but
>> all callers assume that it returns < 0 on error.
>>
>> Since the convention of the test as a whole is the one used by
>> userfault_open(), fix its callers instead. Now the test behaves correctly:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>
>> Signed-off-by: Thiago Jung Bauermann <bauerman at linux.ibm.com>
>
> It seems that this patch is superseded by the second patch in this series.

Yes, but since this is a simple bugfix while the other patch is a
proposed improvement which can be debated, I think it's worthwhile to
keep them separate.

--
Thiago Jung Bauermann
IBM Linux Technology Center

--
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WARNING: multiple messages have this Message-ID (diff)
From: bauerman@linux.ibm.com (Thiago Jung Bauermann)
Subject: [PATCH 1/3] userfaultfd: selftest: Fix checking of userfaultfd_open() result
Date: Mon, 30 Jul 2018 20:53:30 -0300	[thread overview]
Message-ID: <8736w0b7r9.fsf@morokweng.localdomain> (raw)
Message-ID: <20180730235330.p57OvbgdY_1ThKz2CgF0zGtdOzS09shKg9j9GHwwAWo@z> (raw)
In-Reply-To: <20180725135942.GC25188@rapoport-lnx>


Hello Mike,

Thanks for promptly reviewing the patches.

Mike Rapoport <rppt at linux.vnet.ibm.com> writes:

> Hi,
>
> On Tue, Jul 24, 2018@11:42:07PM -0300, Thiago Jung Bauermann wrote:
>> If the userfaultfd test is run on a kernel with CONFIG_USERFAULTFD=n, it
>> will report that the system call is not available yet go ahead and continue
>> anyway:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>   bounces: 0, mode:, register failure
>>
>> This is because userfaultfd_open() returns 0 on success and 1 on error but
>> all callers assume that it returns < 0 on error.
>>
>> Since the convention of the test as a whole is the one used by
>> userfault_open(), fix its callers instead. Now the test behaves correctly:
>>
>>   # ./userfaultfd anon 30 1
>>   nr_pages: 480, nr_pages_per_cpu: 120
>>   userfaultfd syscall not available in this kernel
>>
>> Signed-off-by: Thiago Jung Bauermann <bauerman at linux.ibm.com>
>
> It seems that this patch is superseded by the second patch in this series.

Yes, but since this is a simple bugfix while the other patch is a
proposed improvement which can be debated, I think it's worthwhile to
keep them separate.

--
Thiago Jung Bauermann
IBM Linux Technology Center

--
To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2018-07-30 23:54 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-25  2:42 [PATCH 0/3] userfaultfd: selftest: Improve behavior with older kernels Thiago Jung Bauermann
2018-07-25  2:42 ` Thiago Jung Bauermann
2018-07-25  2:42 ` bauerman
2018-07-25  2:42 ` [PATCH 1/3] userfaultfd: selftest: Fix checking of userfaultfd_open() result Thiago Jung Bauermann
2018-07-25  2:42   ` Thiago Jung Bauermann
2018-07-25  2:42   ` bauerman
2018-07-25 13:59   ` Mike Rapoport
2018-07-25 13:59     ` Mike Rapoport
2018-07-25 13:59     ` rppt
2018-07-30 23:53     ` Thiago Jung Bauermann [this message]
2018-07-30 23:53       ` Thiago Jung Bauermann
2018-07-30 23:53       ` bauerman
2018-07-25  2:42 ` [PATCH 2/3] userfaultfd: selftest: Skip test if a feature isn't supported Thiago Jung Bauermann
2018-07-25  2:42   ` Thiago Jung Bauermann
2018-07-25  2:42   ` bauerman
2018-07-25 14:11   ` Mike Rapoport
2018-07-25 14:11     ` Mike Rapoport
2018-07-25 14:11     ` rppt
2018-07-30 23:54     ` Thiago Jung Bauermann
2018-07-30 23:54       ` Thiago Jung Bauermann
2018-07-30 23:54       ` bauerman
2018-07-25  2:42 ` [PATCH 3/3] userfaultfd: selftest: Report XFAIL if shmem doesn't support zeropage Thiago Jung Bauermann
2018-07-25  2:42   ` Thiago Jung Bauermann
2018-07-25  2:42   ` bauerman
2018-07-25 14:18   ` Mike Rapoport
2018-07-25 14:18     ` Mike Rapoport
2018-07-25 14:18     ` rppt
2018-07-31  0:01     ` Thiago Jung Bauermann
2018-07-31  0:01       ` Thiago Jung Bauermann
2018-07-31  0:01       ` bauerman

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