From 0f7de85a94de553c6cb222b70ac4032d265b362d Mon Sep 17 00:00:00 2001 From: Seiji Aguchi Date: Wed, 14 Nov 2012 20:28:50 +0000 Subject: 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: Seiji Aguchi Acked-by: Mike Waychison Signed-off-by: Tony Luck --- drivers/firmware/efivars.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7ad3aae6e08..bf7a6f994a3 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -681,17 +681,35 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, *count = cnt; timespec->tv_sec = time; timespec->tv_nsec = 0; - get_var_data_locked(efivars, &efivars->walk_entry->var); - size = efivars->walk_entry->var.DataSize; - *buf = kmalloc(size, GFP_KERNEL); - if (*buf == NULL) - return -ENOMEM; - memcpy(*buf, efivars->walk_entry->var.Data, - size); - efivars->walk_entry = list_entry(efivars->walk_entry->list.next, - struct efivar_entry, list); - return size; + } 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); + if (*buf == NULL) + return -ENOMEM; + memcpy(*buf, efivars->walk_entry->var.Data, + size); + 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); -- cgit v1.2.3-70-g09d2