From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Simek <monstr@monstr.eu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Subject: Re: sigaltstack fun (was Re: new execve/kernel_thread design)
Date: Wed, 21 Nov 2012 01:53:02 +0000 [thread overview]
Message-ID: <20121121015302.GQ16916@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFxncW2pEhsjg0AO9YKyvPaHyiXZMjoJZ1J8gA+8sH7HNw@mail.gmail.com>
On Sun, Nov 18, 2012 at 08:45:43AM -1000, Linus Torvalds wrote:
> On Sat, Nov 17, 2012 at 7:45 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > Linus, do you have any objections to the above? FWIW, I've a tentative
> > patchset in that direction (most of it from the last cycle); right now
> > it + stuff currently in signal.git#for-next is at -3.4KLoC and I hadn't
> > dealt with the biarch side of things yet...
>
> I have absolutely no objections. sigaltstack has always been kind of
> messy, and made worse by the fact that it gets effectively no testing
> (because it's generally not used by normal code and even code that
> uses it tends to use it only for very uncommon events). So forcing all
> the sigaltstack code into generic code and at least avoiding the
> "different architectures can get things subtly - or not so subtly -
> wrong in different ways" sounds like a good thing.
OK... Intermediate state (do_sigaltstack() guts still need to be cleaned up
and distributed between the 4 callers) is in signal.git#master right now;
_not_ for merge in that form. Crap found in process:
* microblaze, sparc64 and tile (compat side) have the same bug (see
above). Fixed in that queue.
* score, sh64 and openrisc all tried call do do_sigaltstack() passing
it an address of on-stack copy; no, set_fs() was not used. Fixed in that queue.
* alpha and c6x do not bother to restore saved altstack settings on
sigreturn.
* c6x, cris and hexagon don't bother *saving* altstack settings on
signal arrival. And yes, it does mean that cris and hexagon call
do_sigaltstack() on an unitialized chunk of userland stack. Needs to be
fixed (and in a way that could go into -stable, unfortunately ;-/)
I hadn't done anything serious with altstack users yet; I'm afraid that
this code (i.e. sigframe allocation logics) will also bring a lot of
fun weirdness... ;-/
next prev parent reply other threads:[~2012-11-21 1:53 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20121016223508.GR2616@ZenIV.linux.org.uk>
2012-10-17 5:32 ` new execve/kernel_thread design Max Filippov
2012-10-17 5:43 ` Al Viro
2012-10-17 5:43 ` Al Viro
[not found] ` <CACM3HyEpypULRWUc5ZnLnZ=uOWf3_j=9PXZiJrT_BXyGcQe9yg@mail.gmail.com>
2012-10-17 14:27 ` Michal Simek
2012-10-17 14:27 ` Michal Simek
2012-10-17 16:07 ` Al Viro
2012-10-17 16:07 ` Al Viro
2012-10-17 16:19 ` Al Viro
2012-10-17 16:19 ` Al Viro
2012-11-15 16:41 ` Michal Simek
2012-11-15 16:41 ` Michal Simek
2012-11-15 21:55 ` Al Viro
2012-11-15 21:55 ` Al Viro
2012-11-16 7:59 ` Michal Simek
2012-11-18 5:45 ` sigaltstack fun (was Re: new execve/kernel_thread design) Al Viro
2012-11-18 18:45 ` Linus Torvalds
2012-11-18 19:03 ` sigaltstack fun David Miller
2012-11-18 19:59 ` Al Viro
2012-11-18 19:59 ` Al Viro
2012-11-18 20:48 ` David Miller
2012-11-19 4:55 ` Greg KH
2012-11-18 21:02 ` Al Viro
2012-11-18 21:18 ` David Miller
2012-11-19 1:10 ` Al Viro
2012-11-19 1:30 ` David Miller
2012-11-19 2:35 ` Al Viro
2012-11-19 2:35 ` Al Viro
2012-11-19 3:27 ` David Miller
2012-11-26 5:10 ` Al Viro
2012-11-26 5:15 ` Al Viro
2012-12-04 3:03 ` David Miller
2012-12-04 2:58 ` David Miller
2012-11-21 1:53 ` Al Viro [this message]
2012-10-19 20:25 ` [PATCH] tile: support GENERIC_KERNEL_THREAD and GENERIC_KERNEL_EXECVE Chris Metcalf
2012-10-19 20:25 ` Chris Metcalf
2012-10-19 21:35 ` Al Viro
2012-10-20 13:06 ` Chris Metcalf
2012-10-20 15:34 ` Al Viro
2012-10-20 17:16 ` Al Viro
2012-10-23 17:30 ` Chris Metcalf
2012-10-23 18:41 ` Al Viro
2012-10-23 19:22 ` Chris Metcalf
2012-10-23 20:36 ` Al Viro
2012-10-23 20:36 ` Al Viro
2012-10-25 13:31 ` Chris Metcalf
2012-10-25 14:25 ` Al Viro
2012-10-25 14:25 ` Al Viro
2012-10-23 20:47 ` Thomas Gleixner
2012-10-23 20:47 ` Thomas Gleixner
2012-10-23 20:51 ` Jeff King
2012-10-23 20:51 ` Jeff King
2012-10-23 21:09 ` Catalin Marinas
2012-10-23 21:09 ` Catalin Marinas
2012-10-23 21:22 ` Jeff King
2012-10-23 21:22 ` Jeff King
2012-10-24 11:18 ` Catalin Marinas
2012-10-24 11:18 ` Catalin Marinas
2012-10-23 21:25 ` Thomas Gleixner
2012-10-23 21:47 ` Jeff King
2012-10-23 21:47 ` Jeff King
2012-10-23 22:06 ` Marc Gauthier
2012-10-23 22:06 ` Marc Gauthier
2012-10-23 22:23 ` Jeff King
2012-10-24 6:02 ` Johannes Sixt
2012-10-24 6:02 ` Johannes Sixt
2012-10-24 1:02 ` Linus Torvalds
2012-10-24 1:56 ` Al Viro
2012-10-24 2:14 ` Linus Torvalds
2012-10-24 6:02 ` Ingo Molnar
2012-10-24 6:02 ` Ingo Molnar
2012-10-23 17:30 ` [PATCH] arch/tile: eliminate pt_regs trampolines for syscalls Chris Metcalf
2012-10-23 17:30 ` Chris Metcalf
2012-10-22 14:23 ` [PATCH] tile: support GENERIC_KERNEL_THREAD and GENERIC_KERNEL_EXECVE Catalin Marinas
2012-10-26 18:31 ` [update] Re: new execve/kernel_thread design Al Viro
2012-10-26 18:31 ` Al Viro
2012-10-27 3:32 ` Al Viro
2012-10-27 3:32 ` Al Viro
2012-10-29 7:53 ` Martin Schwidefsky
2012-10-29 7:53 ` Martin Schwidefsky
2012-10-29 13:25 ` Al Viro
2012-10-29 13:25 ` Al Viro
2012-10-29 14:38 ` Martin Schwidefsky
2012-10-29 14:38 ` Martin Schwidefsky
2012-10-29 14:57 ` Al Viro
2012-10-29 14:57 ` Al Viro
2012-12-07 22:23 ` Al Viro
2012-12-07 22:23 ` Al Viro
2012-12-08 2:40 ` Chris Metcalf
2012-12-08 2:40 ` Chris Metcalf
2012-12-13 1:54 ` Hirokazu Takata
2012-12-13 1:54 ` Hirokazu Takata
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