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Message-ID: <CAHp75VfPg3gAWLREcLDU3YYgNaky92tQG8eKDp3sF2wtH8txxw@mail.gmail.com>
Date: Fri, 24 Mar 2017 22:25:41 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Jan Kiszka <jan.kiszka@...mens.com>
Cc: Matt Fleming <matt@...eblueprint.co.uk>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
linux-efi@...r.kernel.org,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"Bryan O'Donoghue" <pure.logic@...us-software.ie>,
Hock Leong Kweh <hock.leong.kweh@...el.com>,
Borislav Petkov <bp@...en8.de>,
Sascha Weisenberger <sascha.weisenberger@...mens.com>
Subject: Re: [PATCH v2 5/7] efi/capsule: Prepare for loading images with
security header
On Fri, Mar 24, 2017 at 7:34 PM, Jan Kiszka <jan.kiszka@...mens.com> wrote:
> The Quark security header is nicely located in front of the capsule
> image, but we still need to pass the image to the update service as if
> there was none. Prepare efi_capsule_update and its user for this by
> defining and evaluating a EFI header displacement in the image located
> in memory. For standard-conforming capsules, this displacement is 0.
To me sounds like new field should be of type size_t.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
> ---
> drivers/firmware/efi/capsule-loader.c | 19 +++++++++++++------
> drivers/firmware/efi/capsule.c | 21 +++++++++++++++++----
> include/linux/efi.h | 1 +
> 3 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c
> index 37d3f6e..59e2694 100644
> --- a/drivers/firmware/efi/capsule-loader.c
> +++ b/drivers/firmware/efi/capsule-loader.c
> @@ -26,6 +26,7 @@ struct capsule_info {
> long index;
> size_t count;
> size_t total_size;
> + unsigned int efi_hdr_displacement;
> struct page **pages;
> size_t page_bytes_remain;
> };
> @@ -83,6 +84,8 @@ static int efi_capsule_setup_info(struct capsule_info *cap_info,
> return ret;
> }
>
> + cap_info->efi_hdr_displacement = 0;
> +
> cap_info->total_size = cap_hdr->imagesize;
> temp_page = krealloc(cap_info->pages,
> pages_needed * sizeof(void *),
> @@ -103,16 +106,20 @@ static int efi_capsule_setup_info(struct capsule_info *cap_info,
> **/
> static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)
> {
> + efi_capsule_header_t *cap_hdr;
> + void *mapped_pages;
> int ret;
> - void *cap_hdr_temp;
>
> - cap_hdr_temp = vmap(cap_info->pages, cap_info->index,
> - VM_MAP, PAGE_KERNEL);
> - if (!cap_hdr_temp)
> + mapped_pages = vmap(cap_info->pages, cap_info->index,
> + VM_MAP, PAGE_KERNEL);
> + if (!mapped_pages)
> return -ENOMEM;
>
> - ret = efi_capsule_update(cap_hdr_temp, cap_info->pages);
> - vunmap(cap_hdr_temp);
> + cap_hdr = mapped_pages + cap_info->efi_hdr_displacement;
> +
> + ret = efi_capsule_update(cap_hdr, cap_info->efi_hdr_displacement,
> + cap_info->pages);
> + vunmap(mapped_pages);
> if (ret) {
> pr_err("capsule update failed\n");
> return ret;
> diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c
> index 6eedff4..a60c4c4 100644
> --- a/drivers/firmware/efi/capsule.c
> +++ b/drivers/firmware/efi/capsule.c
> @@ -184,6 +184,8 @@ efi_capsule_update_locked(efi_capsule_header_t *capsule,
> /**
> * efi_capsule_update - send a capsule to the firmware
> * @capsule: capsule to send to firmware
> + * @efi_hdr_displacement: EFI header offset on first data page (only needed for
> + * non-conforming CSH capsules)
> * @pages: an array of capsule data pages
> *
> * Build a scatter gather list with EFI capsule block descriptors to
> @@ -214,9 +216,12 @@ efi_capsule_update_locked(efi_capsule_header_t *capsule,
> *
> * Return 0 on success, a converted EFI status code on failure.
> */
> -int efi_capsule_update(efi_capsule_header_t *capsule, struct page **pages)
> +int efi_capsule_update(efi_capsule_header_t *capsule,
> + unsigned int efi_hdr_displacement,
> + struct page **pages)
> {
> u32 imagesize = capsule->imagesize;
> + u32 total_size = imagesize + efi_hdr_displacement;
> efi_guid_t guid = capsule->guid;
> unsigned int count, sg_count;
> u32 flags = capsule->flags;
> @@ -224,11 +229,14 @@ int efi_capsule_update(efi_capsule_header_t *capsule, struct page **pages)
> int rv, reset_type;
> int i, j;
>
> - rv = efi_capsule_supported(guid, flags, imagesize, &reset_type);
> + if (efi_hdr_displacement > PAGE_SIZE - sizeof(efi_capsule_header_t))
> + return -EINVAL;
> +
> + rv = efi_capsule_supported(guid, flags, total_size, &reset_type);
> if (rv)
> return rv;
>
> - count = DIV_ROUND_UP(imagesize, PAGE_SIZE);
> + count = DIV_ROUND_UP(total_size, PAGE_SIZE);
> sg_count = sg_pages_num(count);
>
> sg_pages = kzalloc(sg_count * sizeof(*sg_pages), GFP_KERNEL);
> @@ -255,8 +263,13 @@ int efi_capsule_update(efi_capsule_header_t *capsule, struct page **pages)
> for (j = 0; j < SGLIST_PER_PAGE && count > 0; j++) {
> u64 sz = min_t(u64, imagesize, PAGE_SIZE);
>
> - sglist[j].length = sz;
> sglist[j].data = page_to_phys(*pages++);
> + if (efi_hdr_displacement > 0) {
> + sglist[j].data += efi_hdr_displacement;
> + sz -= efi_hdr_displacement;
> + efi_hdr_displacement = 0;
> + }
> + sglist[j].length = sz;
>
> imagesize -= sz;
> count--;
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 94d34e0..d83095c6 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -1403,6 +1403,7 @@ extern int efi_capsule_supported(efi_guid_t guid, u32 flags,
> size_t size, int *reset);
>
> extern int efi_capsule_update(efi_capsule_header_t *capsule,
> + unsigned int efi_hdr_displacement,
> struct page **pages);
>
> #ifdef CONFIG_EFI_RUNTIME_MAP
> --
> 2.10.2
>
--
With Best Regards,
Andy Shevchenko
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