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
>