Commit 003fb0a5 authored by Christian Loehle's avatar Christian Loehle Committed by Ulf Hansson
Browse files

mmc: block: ensure error propagation for non-blk 



Requests to the mmc layer usually come through a block device IO.
The exceptions are the ioctl interface, RPMB chardev ioctl
and debugfs, which issue their own blk_mq requests through
blk_execute_rq and do not query the BLK_STS error but the
mmcblk-internal drv_op_result. This patch ensures that drv_op_result
defaults to an error and has to be overwritten by the operation
to be considered successful.

The behavior leads to a bug where the request never propagates
the error, e.g. by directly erroring out at mmc_blk_mq_issue_rq if
mmc_blk_part_switch fails. The ioctl caller of the rpmb chardev then
can never see an error (BLK_STS_IOERR, but drv_op_result is unchanged)
and thus may assume that their call executed successfully when it did not.

While always checking the blk_execute_rq return value would be
advised, let's eliminate the error by always setting
drv_op_result as -EIO to be overwritten on success (or other error)

Fixes: 614f0388 ("mmc: block: move single ioctl() commands to block requests")
Signed-off-by: default avatarChristian Loehle <cloehle@hyperstone.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/59c17ada35664b818b7bd83752119b2d@hyperstone.com


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent ac9a7868

drivers/mmc/core/block.c

+5 −0
Original line number Diff line number Diff line
@@ -264,6 +264,7 @@ static ssize_t power_ro_lock_store(struct device *dev, 
		goto out_put;

	}

	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_BOOT_WP;

	req_to_mmc_queue_req(req)->drv_op_result = -EIO;

	blk_execute_rq(req, false);

	ret = req_to_mmc_queue_req(req)->drv_op_result;

	blk_mq_free_request(req);
@@ -651,6 +652,7 @@ static int mmc_blk_ioctl_cmd(struct mmc_blk_data *md, 
	idatas[0] = idata;

	req_to_mmc_queue_req(req)->drv_op =

		rpmb ? MMC_DRV_OP_IOCTL_RPMB : MMC_DRV_OP_IOCTL;

	req_to_mmc_queue_req(req)->drv_op_result = -EIO;

	req_to_mmc_queue_req(req)->drv_op_data = idatas;

	req_to_mmc_queue_req(req)->ioc_count = 1;

	blk_execute_rq(req, false);
@@ -722,6 +724,7 @@ static int mmc_blk_ioctl_multi_cmd(struct mmc_blk_data *md, 
	}

	req_to_mmc_queue_req(req)->drv_op =

		rpmb ? MMC_DRV_OP_IOCTL_RPMB : MMC_DRV_OP_IOCTL;

	req_to_mmc_queue_req(req)->drv_op_result = -EIO;

	req_to_mmc_queue_req(req)->drv_op_data = idata;

	req_to_mmc_queue_req(req)->ioc_count = n;

	blk_execute_rq(req, false);
@@ -2806,6 +2809,7 @@ static int mmc_dbg_card_status_get(void *data, u64 *val) 
	if (IS_ERR(req))

		return PTR_ERR(req);

	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_GET_CARD_STATUS;

	req_to_mmc_queue_req(req)->drv_op_result = -EIO;

	blk_execute_rq(req, false);

	ret = req_to_mmc_queue_req(req)->drv_op_result;

	if (ret >= 0) {
@@ -2844,6 +2848,7 @@ static int mmc_ext_csd_open(struct inode *inode, struct file *filp) 
		goto out_free;

	}

	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_GET_EXT_CSD;

	req_to_mmc_queue_req(req)->drv_op_result = -EIO;

	req_to_mmc_queue_req(req)->drv_op_data = &ext_csd;

	blk_execute_rq(req, false);

	err = req_to_mmc_queue_req(req)->drv_op_result;