On 28 March 2017 at 17:18, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote: > On 2017-03-28 17:52, Ard Biesheuvel wrote: >> On 28 March 2017 at 16:43, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote: >>> On 2017-03-28 17:13, Jan Kiszka wrote: >>>> On 2017-03-28 15:49, Ard Biesheuvel wrote: >> [..] >>>>> Could you please have a look at >>>>> >>>>> https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=quark-capsule >>>>> >>>>> and tell me if that would work for you? I will send them out for >>>>> proper review in any case, but to avoid confusion (if I missed >>>>> something obvious), I don't want to send them out just yet. >>>> >>>> There is more needed to make things work again, maybe around passing the >>>> right image size. I'm looking into this. >>>> >>> >>> This makes CSH images being accepted again: >>> >>> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c >>> index 4b6f93f..a4e2311 100644 >>> --- a/arch/x86/platform/efi/quirks.c >>> +++ b/arch/x86/platform/efi/quirks.c >>> @@ -562,6 +562,8 @@ int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, >>> { >>> struct quark_security_header *csh = kbuff; >>> >>> + cap_info->total_size = 0; >>> + >>> if (!x86_match_cpu(quark_ids)) >>> goto fallback; >>> >>> @@ -587,12 +589,16 @@ int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, >>> >>> kbuff += csh->headersize; >>> >>> + cap_info->total_size = csh->headersize; >>> + >>> fallback: >>> if (hdr_bytes < sizeof(efi_capsule_header_t)) >>> return 0; >>> >>> memcpy(&cap_info->header, kbuff, sizeof(cap_info->header)); >>> >>> + cap_info->total_size += cap_info->header.imagesize; >>> + >>> return __efi_capsule_setup_info(cap_info); >>> } >>> >>> diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c >>> index e851951..40dc354 100644 >>> --- a/drivers/firmware/efi/capsule-loader.c >>> +++ b/drivers/firmware/efi/capsule-loader.c >>> @@ -42,7 +42,7 @@ int __efi_capsule_setup_info(struct capsule_info *cap_info) >>> int ret; >>> void *temp_page; >>> >>> - pages_needed = ALIGN(cap_info->header.imagesize, PAGE_SIZE) / PAGE_SIZE; >>> + pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE; >>> >>> if (pages_needed == 0) { >>> pr_err("invalid capsule size"); >>> @@ -59,7 +59,6 @@ int __efi_capsule_setup_info(struct capsule_info *cap_info) >>> return ret; >>> } >>> >>> - cap_info->total_size = cap_info->header.imagesize; >>> temp_page = krealloc(cap_info->pages, >>> pages_needed * sizeof(void *), >>> GFP_KERNEL | __GFP_ZERO); >>> @@ -87,6 +86,8 @@ int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, >>> >>> memcpy(&cap_info->header, kbuff, sizeof(cap_info->header)); >>> >>> + cap_info->total_size = cap_info->header.imagesize; >>> + >>> return __efi_capsule_setup_info(cap_info); >>> } >>> >> >> OK, thanks for debugging that. >> >>> But then my changes to efi_capsule_update are missing the present the >>> right format to the loader. As efi_capsule_update needs to lay out the >>> sg-list in as special way, excluding the CSH on the first page, it needs >>> to know about the displacement. >>> >>> Any suggestions how to address that without rolling back to my aproach? >>> >> >> OK, I'm a bit lost now: for my understanding, could you please >> reiterate how the CSH image deviates from the ordinary one? Or more >> specifically, what exactly is preventing us from simply chopping off >> the CSH header and pushing the capsule header + payload into >> /dev/capsule_loader? >> > > Devices that mandate a signed capsule for updates expect the CSH in > front of the regular capsule image. The interface to UEFI remains > unchanged, i.e. you pass the virtually chopped off capsule, but you have > to leave the CSH in RAM right in front of that very same image. It's a > "nice" side-channel API. > Wow, that is worse than I thought. So my suggestion (which I coded up, please pull again), is to replace the array of struct page pointers with an array of physical addresses in the capsule_info struct. This way, your special version of efi_capsule_setup_info() can advance the first one by the size of the header. I hope this works for you. I am not sure whether imagesize needs to be modified, so I left it alone for now (but I suspect it should be). -- 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
