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Groups > linux.kernel > #1207228
| From | Andy Lutomirski <luto@amacapital.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu |
| Date | 2015-08-14 01:10 +0200 |
| Message-ID | <pX9Nf-QH-21@gated-at.bofh.it> (permalink) |
| References | (10 earlier) <pX8Rc-7Xe-11@gated-at.bofh.it> <pX90R-88q-1@gated-at.bofh.it> <pX9ay-8jE-1@gated-at.bofh.it> <pX9kd-8uM-17@gated-at.bofh.it> <pX9DA-q0-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Aug 13, 2015 at 3:51 PM, Stas Sergeev <stsp@list.ru> wrote:
> 14.08.2015 01:29, Andy Lutomirski пишет:
>>
>> On Thu, Aug 13, 2015 at 3:25 PM, Stas Sergeev <stsp@list.ru> wrote:
>>>
>>> 14.08.2015 01:11, Andy Lutomirski пишет:
>>>
>>>> Now suppose you set some magic flag and jump (via sigreturn,
>>>> trampoline, whatever) into DOS code. The DOS code loads 0x7 into FS
>>>> and then gets #GP. You land in a signal handler. As far as the
>>>> kernel's concerned, the FS base register is whatever the base of LDT
>>>> entry 0 is. What else is the kernel supposed to shove in there?
>>>
>>> The same as what happens when you do in userspace:
>>> ---
>>> asm ("mov $0,%%fs\n");
>>> prctl(ARCH_SET_FS, my_tls_base);
>>> ---
>>>
>>> This was the trick I did before gcc started to use FS in prolog,
>>> now I have to do this in asm.
>>> But how simpler for the kernel is to do the same?
>>>
>>>> I think that making this work fully in the kernel would require a
>>>> full-blown FS equivalent of sigaltstack, and that seems like overkill.
>>>
>>> Setting selector and base is what you call an "equivalent of
>>> sigaltstack"?
>>
>> Yes. sigaltstack says "hey, kernel! here's my SP for signal
>> handling." I think we'd need something similar to tell the kernel
>> what my_tls_base is. Using the most recent thing passed to
>> ARCH_SET_FS is no good because WRFSBASE systems might not use
>> ARCH_SET_FS, and we can't break DOSEMU on Ivy Bridge and newer as soon
>> as we enable WRFSBASE.
>
> If someone uses WRFSBASE and wants things to be preserved
> in a sighandler, he'll just not set the aforementioned flag. No regression.
> Whoever wants to use that flag properly, will not use WRFSBASE,
> and will use ARCH_SET_FS or set_thread_area().
> What exactly breakage do you have in mind?
DOSEMU, when you set that flag, WRFSBASE gets enabled, and glibc's
threading library starts using WRFSBASE instead of arch_prctl.
--Andy
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[regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 02:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 02:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 10:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 18:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 19:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 20:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 21:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 21:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 23:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 23:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 00:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 00:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Ingo Molnar <mingo@kernel.org> - 2015-08-13 10:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 12:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 14:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 17:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 19:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 19:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 19:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 13:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 17:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Brian Gerst <brgerst@gmail.com> - 2015-08-13 19:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 00:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 11:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 17:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 18:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 00:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 12:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 17:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 10:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 20:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 21:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 22:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-13 22:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-13 23:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 23:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-14 00:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 01:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 01:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-14 01:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 00:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 00:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 01:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 02:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 02:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 03:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 03:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 03:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 04:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 03:40 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 02:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 02:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 09:30 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Pavel Emelyanov <xemul@parallels.com> - 2015-08-14 12:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 13:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:00 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 21:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:20 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 21:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:10 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:50 +0200
Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 22:10 +0200
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