From: Simon Horman <horms@verge.net.au>
To: Roel Kluin <12o3l@tiscali.nl>
Cc: tony.luck@intel.com, len.brown@intel.com,
linux-ia64@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH with title] priority fix in acpi_map_lsapic() arch/ia64/kernel/acpi.c
Date: Tue, 20 Nov 2007 06:51:46 +0000 [thread overview]
Message-ID: <20071120065145.GB10490@verge.net.au> (raw)
In-Reply-To: <473CC907.4040106@tiscali.nl>
On Thu, Nov 15, 2007 at 11:32:39PM +0100, Roel Kluin wrote:
> As above should have been its title.
>
> Roel Kluin wrote:
> > I have sent this patch before to lkml, but it appears it wasn't picked up. Also
> > I have to admit this isn't tested. This is a patch against linus' tree.
> >
> > ACPI_MADT_ENABLED is defined 1 (include/acpi/actbl1.h 501)
> > lapic_flags: an u32 of struct acpi_madt_local_sapic (include/acpi/actbl1.h 467)
> > --
> > '!' has a higher priority than '&', so as was
> > this won't test the first bit, but rather evaluates to false for any non-zero
> > lsapic->lapic_flags.
> >
> > Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
This looks correct to me, though I was curious to know why
the problem wasn't manifesting in a bug. I investigated
a bit and found that it seems that the only values
lapic_flags currently takes are 0 and ACPI_MADT_ENABLED,
so it turns out that the bogus logic actually gives the correct result
(by chance).
Acked-by: Simon Horman <horms@verge.net.au>
> > ---
> > diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> > index 3d45d24..7d78d22 100644
> > --- a/arch/ia64/kernel/acpi.c
> > +++ b/arch/ia64/kernel/acpi.c
> > @@ -858,7 +858,7 @@ int acpi_map_lsapic(acpi_handle handle, int *pcpu)
> > lsapic = (struct acpi_madt_local_sapic *)obj->buffer.pointer;
> >
> > if ((lsapic->header.type != ACPI_MADT_TYPE_LOCAL_SAPIC) ||
> > - (!lsapic->lapic_flags & ACPI_MADT_ENABLED)) {
> > + (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))) {
> > kfree(buffer.pointer);
> > return -EINVAL;
> > }
> >
--
Horms
next prev parent reply other threads:[~2007-11-20 6:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-15 22:03 [PATCH] Roel Kluin
2007-11-15 22:32 ` [PATCH with title] priority fix in acpi_map_lsapic() arch/ia64/kernel/acpi.c Roel Kluin
2007-11-20 6:51 ` Simon Horman [this message]
2007-12-04 6:22 ` Len Brown
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