On 8 March 2018 at 15:08, Bastian Stender <bst@xxxxxxxxxxxxxx> wrote: > PARTITION_CONFIG is cached in mmc_card->ext_csd.part_config and the > currently active partition in mmc_blk_data->part_curr. These caches do > not always reflect changes if the ioctl call modifies the > PARTITION_CONFIG registers, e.g. by changing BOOT_PARTITION_ENABLE. > > Write the PARTITION_CONFIG value extracted from the ioctl call to the > cache and update the currently active partition accordingly. This > ensures that the user space cannot change the values behind the > kernel's back. The next call to mmc_blk_part_switch() will operate on > the data set by the ioctl and reflect the changes appropriately. > > Signed-off-by: Bastian Stender <bst@xxxxxxxxxxxxxx> > Signed-off-by: Jan Luebbe <jlu@xxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Thanks, applied for fixes! Kind regards Uffe > --- > drivers/mmc/core/block.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c > index 20135a5de748..2cfb963d9f37 100644 > --- a/drivers/mmc/core/block.c > +++ b/drivers/mmc/core/block.c > @@ -72,6 +72,7 @@ MODULE_ALIAS("mmc:block"); > #define MMC_BLK_TIMEOUT_MS (10 * 1000) > #define MMC_SANITIZE_REQ_TIMEOUT 240000 > #define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16) > +#define MMC_EXTRACT_VALUE_FROM_ARG(x) ((x & 0x0000FF00) >> 8) > > #define mmc_req_rel_wr(req) ((req->cmd_flags & REQ_FUA) && \ > (rq_data_dir(req) == WRITE)) > @@ -586,6 +587,24 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md, > return data.error; > } > > + /* > + * Make sure the cache of the PARTITION_CONFIG register and > + * PARTITION_ACCESS bits is updated in case the ioctl ext_csd write > + * changed it successfully. > + */ > + if ((MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_PART_CONFIG) && > + (cmd.opcode == MMC_SWITCH)) { > + struct mmc_blk_data *main_md = dev_get_drvdata(&card->dev); > + u8 value = MMC_EXTRACT_VALUE_FROM_ARG(cmd.arg); > + > + /* > + * Update cache so the next mmc_blk_part_switch call operates > + * on up-to-date data. > + */ > + card->ext_csd.part_config = value; > + main_md->part_curr = value & EXT_CSD_PART_CONFIG_ACC_MASK; > + } > + > /* > * According to the SD specs, some commands require a delay after > * issuing the command. > -- > 2.16.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html