From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
Peter Anvin <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] de-asmify the x86-64 system call slowpath
Date: Mon, 27 Jan 2014 22:32:57 +0000 [thread overview]
Message-ID: <20140127223257.GE10323@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFzWRjNC4kPeVad3isOOW+vZhnzX0Gk5_8QzD16GZEw5Kg@mail.gmail.com>
On Mon, Jan 27, 2014 at 02:17:23PM -0800, Linus Torvalds wrote:
> On Mon, Jan 27, 2014 at 2:06 PM, Andy Lutomirski <luto@amacapital.net> wrote:
> >
> > It's not just ip and sp -- cs matters here, too, I think.
>
> For signal *delivery*, CS will always be __USER_CS, and %rcx can be
> crap, so sysret should be fine. We could easily check that %rip is
> valid in the whole slow-path instead of saying "return 1 if we did
> do_signal()".
do_signal() is also a place where arbitrary changes to regs might've
been done by tracer, so regs->cs might need to be checked in the same
place where we validate regs->rip ;-/
next prev parent reply other threads:[~2014-01-27 22:33 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-26 22:28 [RFC] de-asmify the x86-64 system call slowpath Linus Torvalds
2014-01-27 0:22 ` Al Viro
2014-01-27 4:32 ` Linus Torvalds
2014-01-27 4:48 ` H. Peter Anvin
2014-01-27 7:42 ` Al Viro
2014-01-27 22:06 ` Andy Lutomirski
2014-01-27 22:17 ` Linus Torvalds
2014-01-27 22:32 ` Al Viro [this message]
2014-01-27 22:43 ` Linus Torvalds
2014-01-27 22:46 ` Andy Lutomirski
2014-01-28 0:22 ` H. Peter Anvin
2014-01-28 0:44 ` Andy Lutomirski
2014-01-27 23:07 ` Al Viro
2014-01-27 10:27 ` Peter Zijlstra
2014-01-27 11:36 ` Al Viro
2014-01-27 17:39 ` Oleg Nesterov
2014-01-28 1:18 ` Al Viro
2014-01-28 16:38 ` Oleg Nesterov
2014-01-28 16:48 ` Al Viro
2014-01-28 17:19 ` Oleg Nesterov
2014-02-06 0:32 ` Linus Torvalds
2014-02-06 0:55 ` Kirill A. Shutemov
2014-02-06 2:32 ` Linus Torvalds
2014-02-06 4:33 ` Linus Torvalds
2014-02-06 21:29 ` Linus Torvalds
2014-02-06 22:24 ` Kirill A. Shutemov
2014-02-07 1:31 ` Linus Torvalds
2014-02-07 15:42 ` [RFC, PATCH] mm: map few pages around fault address if they are in page cache Kirill A. Shutemov
2014-02-07 17:32 ` Andi Kleen
2014-02-07 17:56 ` Kirill A. Shutemov
2014-02-07 18:11 ` Andi Kleen
2014-02-06 5:42 ` [RFC] de-asmify the x86-64 system call slowpath Ingo Molnar
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