 Home |
Products |
Support |
Community |
News |
xen-devel
Re: [Xen-devel] Changing semantics of ioperm() on Xen x86-64?
| To: | Anthony Liguori <aliguori@xxxxxxxxxx> |
|---|---|
| Subject: | Re: [Xen-devel] Changing semantics of ioperm() on Xen x86-64? |
| From: | Keir Fraser <Keir.Fraser@xxxxxxxxxxxx> |
| Date: | Wed, 19 Apr 2006 08:26:58 +0100 |
| Cc: | xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx> |
| Delivery-date: | Wed, 19 Apr 2006 00:33:02 -0700 |
| Envelope-to: | www-data@xxxxxxxxxxxxxxxxxx |
| In-reply-to: | <44455F11.8080007@xxxxxxxxxx> |
| List-help: | <mailto:xen-devel-request@lists.xensource.com?subject=help> |
| List-id: | Xen developer discussion <xen-devel.lists.xensource.com> |
| List-post: | <mailto:xen-devel@lists.xensource.com> |
| List-subscribe: | <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe> |
| List-unsubscribe: | <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe> |
| References: | <44455F11.8080007@xxxxxxxxxx> |
| Sender: | xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
On 18 Apr 2006, at 22:50, Anthony Liguori wrote: As part of the Xen x86-64 Linux port, we've changed the ioperm() syscall to always modify the IOPL instead of actually modifying the IO bitmap in the TSS like we do on x86-32. Is there a particular reason for doing this?I'm completely guessing here that this may allow us to avoid changing the TR when changing from user/kernel mode but that doesn't seem like that huge of a gain.I don't expect that there are many apps that would rely on using ioperm to restrict access to only certain ranges of ports so I don't think this is a security problem but it still is a little discomforting. As Ian said, x86/64 port took an old snap of the i386 port and has gone stale in quite a few ways. It needs some maintenance TLC. i386 did the same thing with ioperm() until io bitmap support was added to Xen. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel |
| <Prev in Thread] | Current Thread | [Next in Thread> |
|---|---|---|
| ||
| Previous by Date: | [Xen-devel] Re: [rfc] [patch] "frame number" size in hypercall ABI, Keir Fraser |
|---|---|
| Next by Date: | Re: [Xen-devel] Re: Quieten the hypervisor, Keir Fraser |
| Previous by Thread: | [Xen-devel] Changing semantics of ioperm() on Xen x86-64?, Anthony Liguori |
| Next by Thread: | RE: [Xen-devel] Changing semantics of ioperm() on Xen x86-64?, Ian Pratt |
| Indexes: | [Date] [Thread] [Top] [All Lists] |
