On Sun, 20 Apr, at 02:28:11AM, Borislav Petkov wrote: > > I guess you can use the kernel_fpu_begin/end() variants here (i.e., > without the "__") which disable and enable preemption and thus drop the > preempt_* calls: > > efi_sync_low_kernel_mappings(); > kernel_fpu_begin(); > __s = efi_call((void *)efi.systab->runtime->f, __VA_ARGS__); > kernel_fpu_end(); > __s; > > I'm not sure about the > > WARN_ON_ONCE(!irq_fpu_usable()); > > thing in kernel_fpu_begin() though, I guess it wouldn't hurt...
Hmm... note that we may call EFI runtime services from interrupt context in efi_pstore_write(), so it seems like it would be possible to trigger that WARN_ON_ONCE() there. Seiji (Cc'd) might have some opinions on this. Either way, if someone sends me a patch ontop of this one that swaps the __kernel_fpu_begin() for kernel_fpu_begin() I can try them out in my lab. -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
