From b093410c9aef29efbf2f4af7b00b2dcc1c119fe8 Mon Sep 17 00:00:00 2001 From: Grant Grundler Date: Wed, 23 Sep 2015 18:30:33 -0700 Subject: [PATCH] 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: Grant Grundler Reviewed-by: Hyung Taek Ryoo Reviewed-by: Gwendal Grignou Tested-by: David Riley Signed-off-by: Ulf Hansson --- drivers/mmc/card/block.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index f6acf0f6c410..23b6c8e8701c 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -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)) @@ -615,19 +615,18 @@ 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); + err = mmc_blk_ioctl_copy_to_user(ic_ptr, idata); cmd_done: mmc_blk_put(md); 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, -- 2.20.1