diff options
| author | Seiji Aguchi <seiji.aguchi@hds.com> | 2012-11-14 21:25:37 +0100 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2012-11-27 01:01:46 +0100 |
| commit | d80a361d779a9f19498943d1ca84243209cd5647 (patch) | |
| tree | 7d142c3dd3b12f5d77aa9c105482bd2a1a9e354d | |
| parent | Linux 3.7-rc7 (diff) | |
| download | linux-d80a361d779a9f19498943d1ca84243209cd5647.tar.xz linux-d80a361d779a9f19498943d1ca84243209cd5647.zip | |
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>
| -rw-r--r-- | drivers/firmware/efivars.c | 18 | ||||
| -rw-r--r-- | include/linux/efi.h | 1 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d10c9873dd9a..37ac21a08751 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; diff --git a/include/linux/efi.h b/include/linux/efi.h index 8670eb1eb8cd..c47ec36f3f39 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -643,6 +643,7 @@ struct efivar_operations { efi_get_variable_t *get_variable; efi_get_next_variable_t *get_next_variable; efi_set_variable_t *set_variable; + efi_query_variable_info_t *query_variable_info; }; struct efivars { |