> Wrong. We do call __pa() on vmalloc ranges (which is a known > uncleanliness that we intend to fix),
AFAIK nobody does actually currently. Although I expect sooner or later someone will try since __ioremap() lost its pgprot argument that made it so powerful. Best would be probably to stick in some bugs just to catch that. > but contrary to your claim the > result is not "random result". On 64-bit it's guaranteed to have a value > above ~66 TB on 64-bit and hence fails all the filters later on so it > has zero practical relevance at the moment. Note that 64bit EFI passes in a fixmap address (they just call it efi_ioremap). Fixmaps are in the kernel mapping which __pa() handles and then this gives a low number likely somewhere in memory and might well trigger. > On 32-bit we transform it > down to somewhere around 1GB - where we check it against the BIOS range > filters - which again cannot trigger. But I do agree that it's unclean > and needs fixing up. Are you sure about this for all possible __PAGE_OFFSET values? e.g. consider 1:3 split. Also there is always relocated kernels where kernels might be loaded quite high. > > static int change_page_attr_addr(struct cpa_data *cpa) > ... > unsigned long phys_addr = __pa(address); > > which for vmalloc area virtual addresses will indeed yield some really > high (and invalid) physical address. That address will never trigger > this check: > > if (within(address, HIGH_MAP_START, HIGH_MAP_END)) > address = (unsigned long) __va(phys_addr); That doesn't check phys_addr at all? > or this check: > > if (within(phys_addr, 0, KERNEL_TEXT_SIZE)) { > > so we'll never actuall _use_ that phys_addr. > and it's on our clean-up > list. But your patch is not a good cleanup because it just hides the > underlying weakness. I never claimed it was a cleanup. It's a fix and a optimization (don't do unnecessary coherency between direct mapping and other mappings for clearing X -- this means some innocent pages in the direct mapping won't get split) Anyways even if you don't want to fix this clear bug I would ask to still consider the optimization independently. -Andi -- 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/