From e74ef2194b41ba5e511fab29fe5ff00e72d2f42a Mon Sep 17 00:00:00 2001

From: Bastian Stender <bst@pengutronix.de>

Date: Thu, 8 Mar 2018 15:08:11 +0100

Subject: [PATCH] mmc: block: fix updating ext_csd caches on ioctl call

Git-commit: e74ef2194b41ba5e511fab29fe5ff00e72d2f42a

Patch-mainline: v4.16-rc7

References: bsc#1051510

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>

Cc: stable@vger.kernel.org

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/mmc/core/block.c |   19 +++++++++++++++++++

 1 file changed, 19 insertions(+)

--- a/drivers/mmc/core/block.c

+++ b/drivers/mmc/core/block.c

@@ -64,6 +64,7 @@ MODULE_ALIAS("mmc:block");

 #define MMC_BLK_TIMEOUT_MS  (10 * 60 * 1000)        /* 10 minute timeout */

 #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))

@@ -543,6 +544,24 @@ static int __mmc_blk_ioctl_cmd(struct mm

 	}

 	/*

+	 * 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.

 	 */