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SubjectRe: [patch] x86, UV: integer wrap bug in uv_hub_ipi_value()
On Mon, Nov 19, 2012 at 06:48:34PM -0600, Russ Anderson wrote:
> On Sat, Nov 17, 2012 at 06:16:11PM +0300, Dan Carpenter wrote:
> > This is a static checker fix. The problem is that we store the bits
> > from "uv_apicid_hibits" into "apicid" (the high 16 bits) but then we
> > shift it 16 bit to the left. "apicid" is an int so it wraps and we lose
> > them.
> Is this the complete patch? phys_apicid is an int, but gets
> cast as unsigned long. Doesn't phys_apicid also have to be
> changed to unsigned long? And why ulong instead of uint (on x86_64)?

Uint is 32bit across all arches in linux and unix, according to
wikipedia. The wakeup_secondary_cpu() function pointer takes an int
so I couldn't change the parameter.

> I agree with changing signed to unsigned where appropriate, but
> this looks like a partial fix. Am I missing something?

I do feel a little embarrassed that I didn't use "unsigned long"
consistently. I just used ulong to make the line a bit shorter, but
I could redo it with "unsigned long" if you want.

dan carpenter

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