Commit b093410c authored by Grant Grundler's avatar Grant Grundler Committed by Ulf Hansson
Browse files

mmc: block: copy resp[] data on err for MMC_IOC_MULTI_CMD 

MMC_IOC_CMD and MMC_IOC_MULTI_CMD ioctl() code currently bails on
any eMMC errors. However, in case there is any resp[] data, we
should attempt to copy resp[] back to user space. The user app
can then determine which command(s) failed in the MMC_IOC_MULTI_CMD
case AND/OR report better diagnostics in both cases.

Gwendal Grignou provided the idea and it was previously implemented
and tested on v3.18 ChromeOS kernel:
    https://chromium-review.googlesource.com/#/c/299956



Signed-off-by: default avatarGrant Grundler <grundler@chromium.org>
Reviewed-by: default avatarHyung Taek Ryoo <hryoo@nvidia.com>
Reviewed-by: default avatarGwendal Grignou <gwendal@chromium.org>
Tested-by: default avatarDavid Riley <davidriley@chromium.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 85f45058

drivers/mmc/card/block.c

+9 −18
Original line number Diff line number Diff line
@@ -595,7 +595,7 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev, 
	struct mmc_blk_ioc_data *idata;

	struct mmc_blk_data *md;

	struct mmc_card *card;

	int err;

	int err = 0, ioc_err = 0;



	idata = mmc_blk_ioctl_copy_from_user(ic_ptr);

	if (IS_ERR(idata))
@@ -615,11 +615,10 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev, 


	mmc_get_card(card);



	err = __mmc_blk_ioctl_cmd(card, md, idata);

	ioc_err = __mmc_blk_ioctl_cmd(card, md, idata);



	mmc_put_card(card);



	if (!err)

	err = mmc_blk_ioctl_copy_to_user(ic_ptr, idata);



cmd_done:
@@ -627,7 +626,7 @@ cmd_done: 
cmd_err:

	kfree(idata->buf);

	kfree(idata);

	return err;

	return ioc_err ? ioc_err : err;

}



static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev,
@@ -637,7 +636,7 @@ static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev, 
	struct mmc_ioc_cmd __user *cmds = user->cmds;

	struct mmc_card *card;

	struct mmc_blk_data *md;

	int i, err = -EFAULT;

	int i, err = 0, ioc_err = 0;

	__u64 num_of_cmds;



	if (copy_from_user(&num_of_cmds, &user->num_of_cmds,
@@ -672,22 +671,14 @@ static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev, 


	mmc_get_card(card);



	for (i = 0; i < num_of_cmds; i++) {

		err = __mmc_blk_ioctl_cmd(card, md, idata[i]);

		if (err) {

			mmc_put_card(card);

			goto cmd_done;

		}

	}

	for (i = 0; i < num_of_cmds && !ioc_err; i++)

		ioc_err = __mmc_blk_ioctl_cmd(card, md, idata[i]);



	mmc_put_card(card);



	/* copy to user if data and response */

	for (i = 0; i < num_of_cmds; i++) {

	for (i = 0; i < num_of_cmds && !err; i++)

		err = mmc_blk_ioctl_copy_to_user(&cmds[i], idata[i]);

		if (err)

			break;

	}



cmd_done:

	mmc_blk_put(md);
@@ -697,7 +688,7 @@ cmd_err: 
		kfree(idata[i]);

	}

	kfree(idata);

	return err;

	return ioc_err ? ioc_err : err;

}



static int mmc_blk_ioctl(struct block_device *bdev, fmode_t mode,

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