Re: Use of the PC value in interrupt/exception handlers

[Piyus Kedia <piyuskedia%gmail.com@localhost>]

Thanks.

On Sat, Aug 3, 2013 at 1:44 AM, Matt Thomas <matt%3am-software.com@localhost> wrote:

On Aug 2, 2013, at 9:41 AM, Piyus Kedia <piyuskedia%gmail.com@localhost> wrote:

> Hi,
>
> I can see a system call sys_rasctl which install a RAS area. So I assume that the RAS PC's will be only user PC's and the cpu_switchto will modify the user PC if it is interrupted in the middle of a RAS.

No. Some architectures use RAS against kernel addresses
but those comparisons against the PC are explicitly done.
(MIPS is an example for implementing the atomic_ops on
MIPS processors which don't have the LL/SC instructions.)