Re: [PATCH v10 3/4] x86, mce: Add __mcsafe_copy()
Am 07.02.2016 um 17:55 schrieb Borislav Petkov:
due to those
> + _ASM_EXTABLE_FAULT(0b,30b)
> + _ASM_EXTABLE_FAULT(1b,31b)
> + _ASM_EXTABLE_FAULT(2b,32b)
> + _ASM_EXTABLE_FAULT(3b,33b)
> + _ASM_EXTABLE_FAULT(4b,34b)
things below and that's because ex_handler_fault() is defined in
arch/x86/mm/extable.c and UML doesn't include that file in the build. It
takes kernel/extable.c and lib/extable.c only.
Richi, what's the usual way to address that in UML? I.e., make an
x86-only symbol visible to the UML build too? Define a dummy one, just
so that it builds?
As discussed on IRC with Boris, UML offers only minimal extable support.
To get rid of the said #ifndef, UML would have to provide its own
extable.c (mostly copy&paste from arch/x86) and an advanced
struct exception_table_entry which includes the trap number.
This implies also that UML can no longer use uaccess.h from asm-generic
or has to add a new ifdef into uaccess.h to whiteout the minimal
struct exception_table_entry from there.
So, I'd vote to keep the #ifndef CONFIG_UML in memcpy_64.S.
As soon you need another #ifndef please ping me and I'll happily
bite the bullet and implement the advanced extable stuff for UML.
Deal?
Thanks,
//richard