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 <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 7ad3aae..bf7a6f9 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -681,17 +681,35 @@
*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);