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Commit f94ec0c0 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 erasing 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 erase 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 erase callback to make it erasable.

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 0f7de85a

drivers/firmware/efivars.c

+18 −2
Original line number Diff line number Diff line
@@ -773,6 +773,8 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, 
{

	char name[DUMP_NAME_LEN];

	efi_char16_t efi_name[DUMP_NAME_LEN];

	char name_old[DUMP_NAME_LEN];

	efi_char16_t efi_name_old[DUMP_NAME_LEN];

	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;

	struct efivars *efivars = psi->data;

	struct efivar_entry *entry, *found = NULL;
@@ -796,8 +798,22 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, 
		if (efi_guidcmp(entry->var.VendorGuid, vendor))

			continue;

		if (utf16_strncmp(entry->var.VariableName, efi_name,

				  utf16_strlen(efi_name)))

				  utf16_strlen(efi_name))) {

			/*

			 * Check if an old format,

			 * which doesn't support holding

			 * multiple logs, remains.

			 */

			sprintf(name_old, "dump-type%u-%u-%lu", type,

				(unsigned int)id, time.tv_sec);



			for (i = 0; i < DUMP_NAME_LEN; i++)

				efi_name_old[i] = name_old[i];



			if (utf16_strncmp(entry->var.VariableName, efi_name_old,

					  utf16_strlen(efi_name_old)))

				continue;

		}



		/* found */

		found = entry;