On 17 March 2017 at 02:09, Dave Young <dyoung@xxxxxxxxxx> wrote: > On 03/16/17 at 12:41pm, Matt Fleming wrote: >> On Mon, 13 Mar, at 03:37:48PM, Dave Young wrote: >> > >> > Omar, could you try below patch? Looking at the efi_mem_desc_lookup, it is not >> > correct to be used in efi_arch_mem_reserve, if it passed your test, I >> > can rewrite patch log with more background and send it out: >> > >> > for_each_efi_memory_desc(md) { >> > [snip] >> > if (!(md->attribute & EFI_MEMORY_RUNTIME) && >> > md->type != EFI_BOOT_SERVICES_DATA && >> > md->type != EFI_RUNTIME_SERVICES_DATA) { >> > continue; >> > } >> > >> > In above code, it meant to get a md of EFI_MEMORY_RUNTIME of either boot >> > data or runtime data, this is wrong for efi_mem_reserve, because we are >> > reserving boot data which has no EFI_MEMORY_RUNTIME attribute at the >> > running time. Just is happened to work and we did not capture the error. >> >> Wouldn't something like this be simpler? >> >> --- >> >> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c >> index 30031d5293c4..cdfe8c628959 100644 >> --- a/arch/x86/platform/efi/quirks.c >> +++ b/arch/x86/platform/efi/quirks.c >> @@ -201,6 +201,10 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) >> return; >> } >> >> + /* No need to reserve regions that will never be freed. */ >> + if (md.attribute & EFI_MEMORY_RUNTIME) >> + return; >> + > > Matt, I think it should be fine although I think the md type checking in > efi_mem_desc_lookup() is causing confusion and not easy to understand.. > > How about move the if chunk early like below because it seems no need > to sanity check the addr + size any more if the md is still RUNTIME? > > --- linux-x86.orig/arch/x86/platform/efi/quirks.c > +++ linux-x86/arch/x86/platform/efi/quirks.c > @@ -196,6 +196,10 @@ void __init efi_arch_mem_reserve(phys_ad > return; > } > > + /* No need to reserve regions that will never be freed. */ > + if (md.attribute & EFI_MEMORY_RUNTIME) > + return; > + > if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) { > pr_err("Region spans EFI memory descriptors, %pa\n", &addr); > return; > This way, we suppress the error it the region spans multiple descriptors, and only the first one has the runtime attribute. So the two patches are not equivalent. I don't have a strong preference either way, though. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html