Re: [PATCH 0/5] x86-32: improve atomic64_t functions (v2)
From: Paul Mackerras
Date: Mon Mar 01 2010 - 03:49:34 EST
On Sun, Feb 28, 2010 at 11:35:31PM -0800, H. Peter Anvin wrote:
> On 02/26/2010 03:23 AM, Luca Barbieri wrote:
> > Sent patches, both to conditionally perform the test and implement the
> > functions for x86 and x86-64.
> Yes, and with the test turned on, the kernel crashes immediately on boot
> on x86-64.
> Some minor investigation reveals the following:
> lib/atomic64.c has the wrong return value for atomic64_add_unless().
> With "wrong" I mean it is the opposite sense compared to
> atomic_add_unless(), not just on x86 but on all architectures.
> Accordingly, I have to conclude that lib/atomic64.c is buggy, and that
> since your test matches that bug, I will have to conclude that your
> x86-32 implementation is also buggy. Thus, please send patches to fix
> your test and your 32-bit implementations (and preferrably
> lib/atomic64.c too, but I can do that just fine.)
> Cc: Paul Mackerras who did the generic atomic64_t implementation for
> verification that this is indeed a bug.
Yes, it sure looks like it. *blush*
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