Hi Johan, On Tue, Nov 22 2011, Johan Rudholm wrote: > Enable boot partitions to be read-only locked until next power on via > a sysfs entry. There will be one sysfs entry for each boot partition: > > /sys/block/mmcblkXbootY/ro_lock_until_next_power_on > > Both boot partitions are locked by writing 1 to one of the files. > > Signed-off-by: John Beckett <[email protected]> > Signed-off-by: Johan Rudholm <[email protected]> > --- > Documentation/mmc/mmc-dev-parts.txt | 13 ++++ > drivers/mmc/card/block.c | 126 ++++++++++++++++++++++++++++++++-- > drivers/mmc/core/mmc.c | 14 +++- > include/linux/mmc/card.h | 10 +++- > include/linux/mmc/mmc.h | 6 ++ > 5 files changed, 158 insertions(+), 11 deletions(-) > > diff --git a/Documentation/mmc/mmc-dev-parts.txt > b/Documentation/mmc/mmc-dev-parts.txt > index 2db28b8..f08d078 100644 > --- a/Documentation/mmc/mmc-dev-parts.txt > +++ b/Documentation/mmc/mmc-dev-parts.txt > @@ -25,3 +25,16 @@ echo 0 > /sys/block/mmcblkXbootY/force_ro > To re-enable read-only access: > > echo 1 > /sys/block/mmcblkXbootY/force_ro > + > +The boot partitions can also be locked read only until the next power on, > +with: > + > +echo 1 > /sys/block/mmcblkXbootY/ro_lock_until_next_power_on > + > +This is a feature of the card and not of the kernel. If the card does > +not support boot partition locking, the file will not exist. If the > +feature has been disabled on the card, the file will be read-only. > + > +The boot partitions can also be locked permanently, but this feature is > +not accessible through sysfs in order to avoid accidental or malicious > +bricking. > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index e0acf2a..2d318b7 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -107,6 +107,8 @@ struct mmc_blk_data { > */ > unsigned int part_curr; > struct device_attribute force_ro; > + struct device_attribute power_ro_lock; > + int area_type; > }; > > static DEFINE_MUTEX(open_lock); > @@ -165,6 +167,74 @@ static void mmc_blk_put(struct mmc_blk_data *md) > mutex_unlock(&open_lock); > } > > +static ssize_t power_ro_lock_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + int ret; > + struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev)); > + struct mmc_card *card = md->queue.card; > + int locked = 0; > + > + if (card->ext_csd.boot_ro_lock > + & EXT_CSD_BOOT_WP_B_PERM_WP_EN) > + locked = 2; > + else if (card->ext_csd.boot_ro_lock > + & EXT_CSD_BOOT_WP_B_PWR_WP_EN) > + locked = 1; > + > + ret = snprintf(buf, PAGE_SIZE, "%d\n", locked); > + > + return ret; > +} > + > +static ssize_t power_ro_lock_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t count) > +{ > + int ret; > + struct mmc_blk_data *md, *part_md; > + struct mmc_card *card; > + unsigned long set; > + > + if (kstrtoul(buf, 0, &set)) > + return -EINVAL; > + > + if (set != 1) > + return count; > + > + md = mmc_blk_get(dev_to_disk(dev)); > + card = md->queue.card; > + > + mmc_claim_host(card->host); > + > + ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP, > + card->ext_csd.boot_ro_lock | > + EXT_CSD_BOOT_WP_B_PWR_WP_EN, > + card->ext_csd.part_time); > + if (ret) > + pr_err("%s: Locking boot partition ro until next power on " > + "failed: %d\n", md->disk->disk_name, ret); > + else > + card->ext_csd.boot_ro_lock |= EXT_CSD_BOOT_WP_B_PWR_WP_EN; > + > + mmc_release_host(card->host); > + > + if (!ret) { > + pr_info("%s: %s\n", md->disk->disk_name, BOOT_PART_MSG);
BOOT_PART_MSG is undefined, so this breaks compilation. Please test and resubmit. Thanks, - Chris. -- Chris Ball <[email protected]> <http://printf.net/> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
