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Commit 0f7de85a authored by Seiji Aguchi's avatar Seiji Aguchi Committed by Tony Luck
Browse files

efi_pstore: Add a format check for an existing variable name at reading time 



[Issue]

a format of variable name has been updated to type, id, count and ctime
to support holding multiple logs.

Format of current variable name
  dump-type0-1-2-12345678

  type:0
  id:1
  count:2
  ctime:12345678

On the other hand, if an old variable name before being updated
remains, users can't read it via /dev/pstore.

Format of old variable name
  dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

[Solution]

This patch add a format check for the old variable name in a read callback
to make it readable.

Signed-off-by: default avatarSeiji Aguchi <seiji.aguchi@hds.com>
Acked-by: default avatarMike Waychison <mikew@google.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 755d4fe4

drivers/firmware/efivars.c

+28 −10
Original line number Diff line number Diff line
@@ -681,6 +681,24 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 
				*count = cnt;

				timespec->tv_sec = time;

				timespec->tv_nsec = 0;

			} else if (sscanf(name, "dump-type%u-%u-%lu",

				   type, &part, &time) == 3) {

				/*

				 * Check if an old format,

				 * which doesn't support holding

				 * multiple logs, remains.

				 */

				*id = part;

				*count = 0;

				timespec->tv_sec = time;

				timespec->tv_nsec = 0;

			} else {

				efivars->walk_entry = list_entry(

						efivars->walk_entry->list.next,

						struct efivar_entry, list);

				continue;

			}



			get_var_data_locked(efivars, &efivars->walk_entry->var);

			size = efivars->walk_entry->var.DataSize;

			*buf = kmalloc(size, GFP_KERNEL);
@@ -688,11 +706,11 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 
				return -ENOMEM;

			memcpy(*buf, efivars->walk_entry->var.Data,

			       size);

				efivars->walk_entry = list_entry(efivars->walk_entry->list.next,

			efivars->walk_entry = list_entry(

					efivars->walk_entry->list.next,

					struct efivar_entry, list);

			return size;

		}

		}

		efivars->walk_entry = list_entry(efivars->walk_entry->list.next,

						 struct efivar_entry, list);

	}