On Wed, Dec 17, 2008 at 8:46 PM, Carlos O'Donell <carlos@xxxxxxxxxxxxxxxx> wrote: > On Wed, Dec 17, 2008 at 5:46 PM, Helge Deller <deller@xxxxxx> wrote: >> The attached patch simply adds the lookup for a fixup handler when trap >> #27 (protection id trap) happens in kernel space. This was missing in >> the code path for trap #27 which is why the kernel then called >> die_if_kernel() and crashed. >> >> Even with this patch ruby1.9 may fail to compile, but at least the >> kernel crashes are gone. >> >> Any feedback welcome. > > Can we avoid copying code from do_page_fault and just call do_page_fault? > > Shouldn't a data protection id trap on a userspace address cause > do_page_fault to be called which triggers the lookup and transfer to > the exception table location? > > Why aren't we doing this in the data protection id trap case? I went all the way back to 2.6.0 and the code is still the same. We must never have generated a protection id trap against user addresses while in the kernel, otherwise we would have noticed this sooner. I think your code is correct and necessary. However! I think you should not duplicate code. Please split out this "bit" of code into a function in mm/fault.c and call it from handle_interruption. Cheers, Carlos. -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
