Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Mon, 2 Dec 2013 02:48:06 -0500
From: Rich Felker <dalias@...ifal.cx>
To: musl@...ts.openwall.com
Subject: Re: Clang powerpc pthread_arch.h patch.

On Sun, Nov 24, 2013 at 04:46:48PM -0600, Richard Pennington wrote:
> On 11/24/2013 04:31 PM, Rich Felker wrote:
> >On Sun, Nov 24, 2013 at 01:23:44PM -0600, Richard Pennington wrote:
> >>I had a problem with clang and __pthread_self() on the powerpc. This
> >>is the patch I applied to work around it.
> >>
> >>Index: pthread_arch.h
> >>===================================================================
> >>--- pthread_arch.h      (revision 3604)
> >>+++ pthread_arch.h      (working copy)
> >>@@ -1,6 +1,11 @@
> >>  static inline struct pthread *__pthread_self()
> >>  {
> >>+#ifdef __clang__
> >>+        char *tp;
> >>+        __asm__ __volatile__ ("mr %0, 2" : "=r" (tp) : : "2" );
> >>+#else
> >Why is "2" in the clobberlist? It's just read, not written. In
> >principle there should be some way to indicate that the asm has hidden
> >state it reads so that it couldn't be reordered before the initial asm
> >call that initializes the register, but that would be massive
> >reordering that's not likely to happen anyway. I'm not sure what the
> >right way to encode this as a constraint is...
> >
> >Rich
> Hi Rich,
> 
> You're right about the clobber list. Not that it matters much in
> this case I think.

Committed a fix based on your patch; let me know if you still have
problems with it.

Rich

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.