lkml.org 
[lkml]   [2018]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2] efi: take size of partition entry from GPT header
On 11 September 2018 at 18:15, Eugene Korenevsky <ekorenevsky@gmail.com> wrote:
> Use gpt_header.sizeof_partition_entry instead of sizeof(gpt_entry)
> for GPT entry size.
> According to UEFI 2.7 spec 5.3.1 "GPT overview":, the size of a GUID Partition
> Entry element is defined in the Size Of Partition Entry field of GPT header.
> The GPT with entries sized more than sizeof(gpt_entry) is not illegal.
> OVMF firmware from EDK2 perfectly works with it, see edk2-tianocore source
> code.
>
> Changes since v1: refactoring (extract get_gpt_entry function),
> fix (&ptes[i] -> pte)
>
> Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
> ---
> block/partitions/efi.c | 32 ++++++++++++++++++--------------
> 1 file changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/block/partitions/efi.c b/block/partitions/efi.c
> index 39f70d968754..724f7c0805a2 100644
> --- a/block/partitions/efi.c
> +++ b/block/partitions/efi.c
> @@ -428,11 +428,6 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
> (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
> goto fail;
> }
> - /* Check that sizeof_partition_entry has the correct value */
> - if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
> - pr_debug("GUID Partition Entry Size check failed.\n");
> - goto fail;
> - }
>

As I asked you before, can we keep this sanity check but change != to < ?

> /* Sanity check partition table size */
> pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) *
> @@ -670,6 +665,11 @@ static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
> return 0;
> }
>
> +static gpt_entry *get_gpt_entry(gpt_header *gpt_hdr, gpt_entry *ptes, u32 index)
> +{
> + return (gpt_entry *)((u8 *)ptes + gpt->sizeof_partition_entry * index);
> +}
> +
> /**
> * efi_partition(struct parsed_partitions *state)
> * @state: disk parsed partitions
> @@ -704,32 +704,36 @@ int efi_partition(struct parsed_partitions *state)
>
> pr_debug("GUID Partition Table is valid! Yea!\n");
>
> - for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
> + for (i = 0;
> + i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1;
> + i++) {
> + gpt_entry *pte = get_gpt_entry(gpt, ptes, i);
> struct partition_meta_info *info;
> unsigned label_count = 0;
> unsigned label_max;
> - u64 start = le64_to_cpu(ptes[i].starting_lba);
> - u64 size = le64_to_cpu(ptes[i].ending_lba) -
> - le64_to_cpu(ptes[i].starting_lba) + 1ULL;
> + u64 start = le64_to_cpu(pte->starting_lba);
> + u64 size = le64_to_cpu(pte->ending_lba) -
> + le64_to_cpu(pte->starting_lba) + 1ULL;
>
> - if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
> + if (!is_pte_valid(pte, last_lba(state->bdev)))
> continue;
>
> put_partition(state, i+1, start * ssz, size * ssz);
>
> /* If this is a RAID volume, tell md */
> - if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
> + if (!efi_guidcmp(
> + pte->partition_type_guid, PARTITION_LINUX_RAID_GUID))
> state->parts[i + 1].flags = ADDPART_FLAG_RAID;
>
> info = &state->parts[i + 1].info;
> - efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
> + efi_guid_to_str(&pte->unique_partition_guid, info->uuid);
>
> /* Naively convert UTF16-LE to 7 bits. */
> label_max = min(ARRAY_SIZE(info->volname) - 1,
> - ARRAY_SIZE(ptes[i].partition_name));
> + ARRAY_SIZE(pte->partition_name));
> info->volname[label_max] = 0;
> while (label_count < label_max) {
> - u8 c = ptes[i].partition_name[label_count] & 0xff;
> + u8 c = pte->partition_name[label_count] & 0xff;
> if (c && !isprint(c))
> c = '!';
> info->volname[label_count] = c;
> --
> 2.18.0
>

\
 
 \ /
  Last update: 2018-09-12 01:00    [W:0.113 / U:3.892 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site