From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Stas Sergeev <stsp@list.ru>
Cc: Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Brian Gerst <brgerst@gmail.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>,
Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [RFC 3/4] x86/signal/64: Re-add support for SS in the 64-bit signal context
Date: Wed, 14 Oct 2015 20:01:46 +0300 [thread overview]
Message-ID: <20151014170146.GU2048@uranus> (raw)
In-Reply-To: <561E895E.7050905@list.ru>
On Wed, Oct 14, 2015 at 07:57:02PM +0300, Stas Sergeev wrote:
...
> > correct? This should work for us. Stas, mind to refresh my memory,
> > which ss value doesmu setups here?
>
> Nothing.
> Older dosemus didn't care about touching __pad0, so
> whatever kernel saves there, is still there, even when
> dosemu needs another value.
> The problem starts to happen IIRC when dosemu invalidates
> the LDT entry that was previously saved by the kernel as an SS.
> IIRC this was causing the SIGSEGV right from sigreturn().
> It is actually a bit annoying to have such bad code in kernel
> only for the sake of the older dosemu.
I see. Thanks a huge for info!
next prev parent reply other threads:[~2015-10-14 17:01 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-13 1:04 [RFC 0/4] x86: sigcontext SS fixes, take 2 Andy Lutomirski
2015-10-13 1:04 ` [RFC 1/4] x86/signal/64: Add a comment about sigcontext->fs and gs Andy Lutomirski
2015-10-13 1:04 ` [RFC 2/4] x86/signal/64: Fix SS if needed when delivering a 64-bit signal Andy Lutomirski
2015-10-13 1:04 ` [RFC 3/4] x86/signal/64: Re-add support for SS in the 64-bit signal context Andy Lutomirski
2015-10-13 14:59 ` Stas Sergeev
2015-10-14 15:01 ` Ingo Molnar
2015-10-14 15:09 ` Stas Sergeev
2015-10-14 16:40 ` Andy Lutomirski
2015-10-14 17:40 ` Stas Sergeev
2015-10-14 18:06 ` Andy Lutomirski
2015-10-14 18:34 ` Stas Sergeev
2015-10-14 18:52 ` Andy Lutomirski
2015-10-14 21:37 ` Stas Sergeev
2015-10-14 21:41 ` Andy Lutomirski
2015-10-18 13:36 ` Stas Sergeev
2015-10-18 16:12 ` Andy Lutomirski
2015-10-18 16:29 ` Stas Sergeev
2015-10-18 16:36 ` Andy Lutomirski
2015-10-18 16:43 ` Stas Sergeev
2015-10-18 17:06 ` Andy Lutomirski
2015-10-14 16:40 ` Cyrill Gorcunov
2015-10-14 16:42 ` Andy Lutomirski
2015-10-14 16:57 ` Cyrill Gorcunov
2015-10-14 16:57 ` Stas Sergeev
2015-10-14 17:01 ` Cyrill Gorcunov [this message]
2015-10-13 1:04 ` [RFC 4/4] selftests/x86: Add tests for UC_SIGCONTEXT_SS and UC_STRICT_RESTORE_SS Andy Lutomirski
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