Acked-by: Mike Waychison <mikew@xxxxxxxxxx> On Wed, Oct 24, 2012 at 6:51 PM, Seiji Aguchi <seiji.aguchi@xxxxxxx> wrote: > [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@xxxxxxx> > --- > drivers/firmware/efivars.c | 18 ++++++++++++++++++ > 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 d10c987..37ac21a 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 8670eb1..c47ec36 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 { > -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
