On Mon, Dec 14, 2015 at 12:26 PM, Pavel Machek <pa...@ucw.cz> wrote: > Hi! > >> > I know. But either someone cares, and it should be fixes, or noone >> > cares, and the check should be removed. >> >> Someone cares, and it should be scheduled to be fixed for 4.5. The EFI >> mapping changes that were required to avoid the warning were much too >> big and late to make 4.4. >> >> So for now, don't enable CONFIG_DEBUG_WX for now. Unless you want to >> actively debug the EFI mapping changes, that is. Which I heartily >> recommend people doing. > > Ok, good, except... This is thinkpad X60. Good old BIOS. It should > have no EFI. > > pavel@duo:~$ dmesg | grep EFI > pavel@duo:~$ > > From the messages I got: > >> [ 3.285993] x86/mm: Found insecure W+X mapping at address >> ffe69000/0xffe69000 > > ---[ Persisent kmap() Area ]--- > 0xffc00000-0xffd28000 1184K pte > 0xffd28000-0xffddd000 724K RW GLB NX pte > 0xffddd000-0xffe69000 560K pte > 0xffe69000-0xffe6e000 20K RW GLB x pte > 0xffe6e000-0xffe6f000 4K pte > ---[ Fixmap Area ]--- > > That is not EFI, right?
That's weird. The only API to do that seems to be manually setting kmap_prot to _PAGE_KERNEL_EXEC, and nothing does that. (Why is kmap_prot a variable on x86 at all? It has exactly one writer, and that's the code that initializes it in the first place. Shouldn't we #define kmap_prot _PAGE_KERNEL? --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
