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authorSeiji Aguchi <seiji.aguchi@hds.com>2012-11-14 20:25:37 +0000
committerTony Luck <tony.luck@intel.com>2012-11-26 16:01:46 -0800
commitd80a361d779a9f19498943d1ca84243209cd5647 (patch)
tree7d142c3dd3b12f5d77aa9c105482bd2a1a9e354d /drivers/firmware
parent9489e9dcae718d5fde988e4a684a0f55b5f94d17 (diff)
efi_pstore: Check remaining space with QueryVariableInfo() before writing data
[Issue] As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario. And we wouldn't expect all firmware to handle it gracefully. http://marc.info/?l=linux-kernel&m=134305325801789&w=2 On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time. Therefore, efi_pstore may not work if it tries to write a large amount of data. [Patch Description] To avoid handling the situation above, this patch checks if there is a space enough to log with QueryVariableInfo() before writing data. 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>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efivars.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index d10c9873dd9..37ac21a0875 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -707,12 +707,29 @@ static int efi_pstore_write(enum pstore_type_id type,
struct efivars *efivars = psi->data;
struct efivar_entry *entry, *found = NULL;
int i, ret = 0;
+ u64 storage_space, remaining_space, max_variable_size;
+ efi_status_t status = EFI_NOT_FOUND;
sprintf(stub_name, "dump-type%u-%u-", type, part);
sprintf(name, "%s%lu", stub_name, get_seconds());
spin_lock(&efivars->lock);
+ /*
+ * Check if there is a space enough to log.
+ * size: a size of logging data
+ * DUMP_NAME_LEN * 2: a maximum size of variable name
+ */
+ status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES,
+ &storage_space,
+ &remaining_space,
+ &max_variable_size);
+ if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
+ spin_unlock(&efivars->lock);
+ *id = part;
+ return -ENOSPC;
+ }
+
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = stub_name[i];
@@ -1237,6 +1254,7 @@ efivars_init(void)
ops.get_variable = efi.get_variable;
ops.set_variable = efi.set_variable;
ops.get_next_variable = efi.get_next_variable;
+ ops.query_variable_info = efi.query_variable_info;
error = register_efivars(&__efivars, &ops, efi_kobj);
if (error)
goto err_put;