@@ -2329,6 +2329,13 @@ static const struct file_operations mmc_rpmb_fileops = {
#endif
};
+static void mmc_blk_rpmb_device_release(struct device *dev)
+{
+ struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
+
+ ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
+ kfree(rpmb);
+}
static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
struct mmc_blk_data *md,
@@ -2347,8 +2354,10 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
return devidx;
rpmb = kzalloc(sizeof(*rpmb), GFP_KERNEL);
- if (!rpmb)
+ if (!rpmb) {
+ ida_simple_remove(&mmc_rpmb_ida, devidx);
return -ENOMEM;
+ }
snprintf(rpmb_name, sizeof(rpmb_name),
"mmcblk%u%s", card->host->index, subname ? subname : "");
@@ -2359,6 +2368,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
rpmb->dev.bus = &mmc_rpmb_bus_type;
rpmb->dev.devt = MKDEV(MAJOR(mmc_rpmb_devt), rpmb->id);
rpmb->dev.parent = &card->dev;
+ rpmb->dev.release = mmc_blk_rpmb_device_release;
device_initialize(&rpmb->dev);
dev_set_drvdata(&rpmb->dev, rpmb);
rpmb->md = md;
@@ -2368,7 +2378,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
ret = cdev_device_add(&rpmb->chrdev, &rpmb->dev);
if (ret) {
pr_err("%s: could not add character device\n", rpmb_name);
- goto out_remove_ida;
+ goto out_put_device;
}
list_add(&rpmb->node, &md->rpmbs);
@@ -2383,18 +2393,16 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
return 0;
-out_remove_ida:
- ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
- kfree(rpmb);
+out_put_device:
+ put_device(&rpmb->dev);
return ret;
}
static void mmc_blk_remove_rpmb_part(struct mmc_rpmb_data *rpmb)
+
{
cdev_device_del(&rpmb->chrdev, &rpmb->dev);
- device_del(&rpmb->dev);
- ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
- kfree(rpmb);
+ put_device(&rpmb->dev);
}
/* MMC Physical partitions consist of two boot partitions and
I forgot to account for the fact that the device core holds a reference to a device added with device_initialize() that need to be released with a corresponding put_device() to reach a 0 refcount at the end of the lifecycle. This led to a NULL pointer reference when freeing the device when e.g. unbidning the host device in sysfs. Fix this and use the device .release() callback to free the IDA and free:ing the memory used by the RPMB device. Before this patch: /sys/bus/amba/drivers/mmci-pl18x$ echo 80114000.sdi4_per2 > unbind [ 29.797332] mmc3: card 0001 removed [ 29.810791] Unable to handle kernel NULL pointer dereference at virtual address 00000050 [ 29.818878] pgd = de70c000 [ 29.821624] [00000050] *pgd=1e70a831, *pte=00000000, *ppte=00000000 [ 29.827911] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [ 29.833282] Modules linked in: [ 29.836334] CPU: 1 PID: 154 Comm: sh Not tainted 4.14.0-rc3-00039-g83318e309566-dirty #736 [ 29.844604] Hardware name: ST-Ericsson Ux5x0 platform (Device Tree Support) [ 29.851562] task: de572700 task.stack: de742000 [ 29.856079] PC is at kernfs_find_ns+0x8/0x100 [ 29.860443] LR is at kernfs_find_and_get_ns+0x30/0x48 After this patch: /sys/bus/amba/drivers/mmci-pl18x$ echo 80005000.sdi4_per2 > unbind [ 20.623382] mmc3: card 0001 removed Fixes: 0ab0c7c0e65a ("mmc: block: Convert RPMB to a character device") Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - Drop the print from removing the RPMB partition - Refactor the error path of the RPMB to use refcounting - Drop the verbose comment on refcounts --- drivers/mmc/core/block.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) -- 2.13.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html