From: Dmitry Safonov <dsafonov@virtuozzo.com>
To: Andy Lutomirski <luto@amacapital.net>, Ingo Molnar <mingo@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Dmitry Safonov <0x7f454c46@gmail.com>,
Shuah Khan <shuahkh@osg.samsung.com>,
<linux-kselftest@vger.kernel.org>
Subject: Re: [PATCHv8 resend 2/2] selftest/x86: add mremap vdso test
Date: Tue, 17 May 2016 13:25:04 +0300 [thread overview]
Message-ID: <7d74b270-01dd-aab9-8133-249fe9a52767@virtuozzo.com> (raw)
In-Reply-To: <CALCETrWCPNF8njicMutsWkeHRheDjh14x+Np=pAhMojm2_6AJw@mail.gmail.com>
On 05/16/2016 09:25 PM, Andy Lutomirski wrote:
> On Mon, May 16, 2016 at 9:24 AM, Dmitry Safonov <dsafonov@virtuozzo.com> wrote:
>> On 05/16/2016 04:54 PM, Ingo Molnar wrote:
>>>
>>>
>>> * Dmitry Safonov <dsafonov@virtuozzo.com> wrote:
>>>
>>>> Should print on success:
>>>> [root@localhost ~]# ./test_mremap_vdso_32
>>>> AT_SYSINFO_EHDR is 0xf773f000
>>>> [NOTE] Moving vDSO: [f773f000, f7740000] -> [a000000, a001000]
>>>> [OK]
>>>> Or segfault if landing was bad (before patches):
>>>> [root@localhost ~]# ./test_mremap_vdso_32
>>>> AT_SYSINFO_EHDR is 0xf774f000
>>>> [NOTE] Moving vDSO: [f774f000, f7750000] -> [a000000, a001000]
>>>> Segmentation fault (core dumped)
>>>
>>>
>>> Can the segfault be caught and recovered from, to print a proper failure
>>> message?
>>
>>
>> Will add segfault handler, thanks.
>>
>
> It may be more complicated that that. Glibc is likely to explode if
> this happens, and the headers are sufficiently screwed up that it's
> awkward to bypass glibc and call rt_sigaction directly. I have a test
> that does the latter, though, so it's at least possible, but I'm
> unconvinced it's worth it just for an error message.
Oh, I didn't know that, thanks, Andy.
I'll leave it as is for simplicity.
--
Regards,
Dmitry Safonov
next prev parent reply other threads:[~2016-05-17 10:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-10 13:29 [PATCHv8 resend 1/2] x86/vdso: add mremap hook to vm_special_mapping Dmitry Safonov
2016-05-10 13:29 ` [PATCHv8 resend 2/2] selftest/x86: add mremap vdso test Dmitry Safonov
2016-05-16 13:54 ` Ingo Molnar
2016-05-16 16:24 ` Dmitry Safonov
2016-05-16 18:25 ` Andy Lutomirski
2016-05-17 10:25 ` Dmitry Safonov [this message]
2016-05-16 9:38 ` [PATCHv8 resend 1/2] x86/vdso: add mremap hook to vm_special_mapping Dmitry Safonov
2016-05-16 10:54 ` Ingo Molnar
2016-05-16 11:14 ` Dmitry Safonov
2016-05-16 13:55 ` Ingo Molnar
2016-05-16 16:23 ` Dmitry Safonov
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