Re: [Qemu-devel] [PATCH 4/4] tcg-hppa: Compute is_write in cpu_signal_handler.

[Richard Henderson]

On 03/16/2010 07:23 PM, Stuart Brady wrote:
> On Wed, Mar 17, 2010 at 02:10:43AM +0000, Stuart Brady wrote:
>> Argh.  It just seems mind bogglingly silly that is_write doesn't seem to
>> be included in the siginfo on archs where doing so would make sense...
> 
>> It's at least something I'd have hoped libc could take care of in the case
>> where the hardware doesn't indicate whether the fault was due to a read
>> or a write...
> 
> Oh, actually, I guess you'd just test the equivalent of
> '(info->si_isr >> 33) & 1' or 'DSISR_sig(uc) & 0x00800000)' on such
> an arch, but it still seems a shame that this isn't done for us on
> archs without that ability...

Unfortunately there's no reserved space in the hppa sigcontext, which
is what would need to be expanded in order to store the additional info
from the kernel.  So in addition to a kernel patch, userland would need
to change its abi.  All kinda nasty, that.


r~