From: Dave Anderson <anderson@redhat.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, jstancek@redhat.com
Subject: Re: [PATCH] x86-64: Prevent gcc from optimizing away venosys_1()
Date: Fri, 3 Jun 2011 17:32:06 -0400 (EDT) [thread overview]
Message-ID: <1972495451.7278.1307136726542.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com> (raw)
In-Reply-To: <20110603204847.GM27166@one.firstfloor.org>
----- Original Message -----
> > return 0;
> > }
> >
> > -static long __vsyscall(3) venosys_1(void)
> > +long __vsyscall(3) venosys_1(void)
>
> Better add a __used too. Otherwise it can be optimized out again
> in some builds e.g. when someone enables gc-sections for the linker.
Considering that all of the vsyscall prototypes have this attribute:
#define __vsyscall(nr) \
__attribute__ ((unused, __section__(".vsyscall_" #nr))) notrace
How would any of them work?
Dave
>
> -Andi
> --
> ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2011-06-03 21:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <313387488.1201.1307114323524.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com>
2011-06-03 15:20 ` Dave Anderson
2011-06-03 20:48 ` Andi Kleen
2011-06-03 21:32 ` Dave Anderson [this message]
2011-06-03 21:37 ` Andi Kleen
2011-06-06 17:22 ` Ingo Molnar
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