3.16.57-rc1 review patch. If anyone has any objections, please let me know.
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From: Bastian Stender bst@pengutronix.de
commit e74ef2194b41ba5e511fab29fe5ff00e72d2f42a upstream.
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@pengutronix.de Signed-off-by: Jan Luebbe jlu@pengutronix.de Signed-off-by: Ulf Hansson ulf.hansson@linaro.org [bwh: Backported to 3.16: - Also add the definition of MMC_EXTRACT_INDEX_FROM_ARG() - Adjust filename, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -67,6 +67,9 @@ MODULE_ALIAS("mmc:block"); #define PACKED_CMD_VER 0x01 #define PACKED_CMD_WR 0x02
+#define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16) +#define MMC_EXTRACT_VALUE_FROM_ARG(x) ((x & 0x0000FF00) >> 8) + static DEFINE_MUTEX(block_mutex);
/* @@ -569,6 +572,24 @@ static int mmc_blk_ioctl_cmd(struct bloc }
/* + * 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. */