device-dax: Fix range release

There are multiple locations that open-code the release of the last
range in a device-dax instance. Consolidate this into a new
dev_dax_trim_range() helper.

This also addresses a kmemleak report:

# cat /sys/kernel/debug/kmemleak
[..]
unreferenced object 0xffff976bd46f6240 (size 64):
   comm "ndctl", pid 23556, jiffies 4299514316 (age 5406.733s)
   hex dump (first 32 bytes):
     00 00 00 00 00 00 00 00 00 00 20 c3 37 00 00 00  .......... .7...
     ff ff ff 7f 38 00 00 00 00 00 00 00 00 00 00 00  ....8...........
   backtrace:
     [<00000000064003cf>] __kmalloc_track_caller+0x136/0x379
     [<00000000d85e3c52>] krealloc+0x67/0x92
     [<00000000d7d3ba8a>] __alloc_dev_dax_range+0x73/0x25c
     [<0000000027d58626>] devm_create_dev_dax+0x27d/0x416
     [<00000000434abd43>] __dax_pmem_probe+0x1c9/0x1000 [dax_pmem_core]
     [<0000000083726c1c>] dax_pmem_probe+0x10/0x1f [dax_pmem]
     [<00000000b5f2319c>] nvdimm_bus_probe+0x9d/0x340 [libnvdimm]
     [<00000000c055e544>] really_probe+0x230/0x48d
     [<000000006cabd38e>] driver_probe_device+0x122/0x13b
     [<0000000029c7b95a>] device_driver_attach+0x5b/0x60
     [<0000000053e5659b>] bind_store+0xb7/0xc3
     [<00000000d3bdaadc>] drv_attr_store+0x27/0x31
     [<00000000949069c5>] sysfs_kf_write+0x4a/0x57
     [<000000004a8b5adf>] kernfs_fop_write+0x150/0x1e5
     [<00000000bded60f0>] __vfs_write+0x1b/0x34
     [<00000000b92900f0>] vfs_write+0xd8/0x1d1

Reported-by: Jane Chu <jane.chu@oracle.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/160834570161.1791850.14911670304441510419.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2020-12-18 18:41:41 -08:00
parent 8bcbe3132c
commit 6268d7da4d

View File

@ -367,19 +367,28 @@ void kill_dev_dax(struct dev_dax *dev_dax)
}
EXPORT_SYMBOL_GPL(kill_dev_dax);
static void free_dev_dax_ranges(struct dev_dax *dev_dax)
static void trim_dev_dax_range(struct dev_dax *dev_dax)
{
int i = dev_dax->nr_range - 1;
struct range *range = &dev_dax->ranges[i].range;
struct dax_region *dax_region = dev_dax->region;
int i;
device_lock_assert(dax_region->dev);
for (i = 0; i < dev_dax->nr_range; i++) {
struct range *range = &dev_dax->ranges[i].range;
dev_dbg(&dev_dax->dev, "delete range[%d]: %#llx:%#llx\n", i,
(unsigned long long)range->start,
(unsigned long long)range->end);
__release_region(&dax_region->res, range->start,
range_len(range));
__release_region(&dax_region->res, range->start, range_len(range));
if (--dev_dax->nr_range == 0) {
kfree(dev_dax->ranges);
dev_dax->ranges = NULL;
}
dev_dax->nr_range = 0;
}
static void free_dev_dax_ranges(struct dev_dax *dev_dax)
{
while (dev_dax->nr_range)
trim_dev_dax_range(dev_dax);
}
static void unregister_dev_dax(void *dev)
@ -804,15 +813,10 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
return 0;
rc = devm_register_dax_mapping(dev_dax, dev_dax->nr_range - 1);
if (rc) {
dev_dbg(dev, "delete range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
&alloc->start, &alloc->end);
dev_dax->nr_range--;
__release_region(res, alloc->start, resource_size(alloc));
return rc;
}
if (rc)
trim_dev_dax_range(dev_dax);
return 0;
return rc;
}
static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size)
@ -885,12 +889,7 @@ static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
if (shrink >= range_len(range)) {
devm_release_action(dax_region->dev,
unregister_dax_mapping, &mapping->dev);
__release_region(&dax_region->res, range->start,
range_len(range));
dev_dax->nr_range--;
dev_dbg(dev, "delete range[%d]: %#llx:%#llx\n", i,
(unsigned long long) range->start,
(unsigned long long) range->end);
trim_dev_dax_range(dev_dax);
to_shrink -= shrink;
if (!to_shrink)
break;
@ -1267,7 +1266,6 @@ static void dev_dax_release(struct device *dev)
put_dax(dax_dev);
free_dev_dax_id(dev_dax);
dax_region_put(dax_region);
kfree(dev_dax->ranges);
kfree(dev_dax->pgmap);
kfree(dev_dax);
}