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[Xen-devel] Event Channel API Oops

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Subject: [Xen-devel] Event Channel API Oops
From: Adam Wick <awick@xxxxxxxxxx>
Date: Mon, 13 Aug 2007 15:02:12 -0700
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Hello -

I was just writing some code using the xenctrl library. During my testing, I was hitting some error cases in the event channel support but not realizing it due to a problem in the API.

Several of the event channel API's (_bind_unbound_port, _bind_interdomain, _bind_virq, and _pending in xenctrl.h) state that they return -1 on error. As it turns out, however, the return value type (evtchn_port_t, which is uint32_t in event_channel.h) is unsigned. Thus, testing for < 0 on the return type will always fail, because there are no negative numbers for the type.

I don't have a patch, because I'm not sure how you think this is best fixed, but just wanted to give you a heads up.

Adam Wick
Galois, Inc.

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