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authorDan Williams <dan.j.williams@intel.com>2022-11-03 17:30:36 -0700
committerDan Williams <dan.j.williams@intel.com>2022-11-04 15:58:35 -0700
commit4d07ae22e79ebc2d7528bbc69daa53b86981cb3a (patch)
tree1464e53baab41aaddac96f01b399a4b1b43fee0d /drivers/cxl
parent0d9e734018d70cecf79e2e4c6082167160a0f13f (diff)
cxl/pmem: Fix cxl_pmem_region and cxl_memdev leak
When a cxl_nvdimm object goes through a ->remove() event (device physically removed, nvdimm-bridge disabled, or nvdimm device disabled), then any associated regions must also be disabled. As highlighted by the cxl-create-region.sh test [1], a single device may host multiple regions, but the driver was only tracking one region at a time. This leads to a situation where only the last enabled region per nvdimm device is cleaned up properly. Other regions are leaked, and this also causes cxl_memdev reference leaks. Fix the tracking by allowing cxl_nvdimm objects to track multiple region associations. Cc: <stable@vger.kernel.org> Link: https://github.com/pmem/ndctl/blob/main/test/cxl-create-region.sh [1] Reported-by: Vishal Verma <vishal.l.verma@intel.com> Fixes: 04ad63f086d1 ("cxl/region: Introduce cxl_pmem_region objects") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/166752183647.947915.2045230911503793901.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
-rw-r--r--drivers/cxl/core/pmem.c2
-rw-r--r--drivers/cxl/cxl.h2
-rw-r--r--drivers/cxl/pmem.c101
3 files changed, 68 insertions, 37 deletions
diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index 1d12a8206444..36aa5070d902 100644
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -188,6 +188,7 @@ static void cxl_nvdimm_release(struct device *dev)
{
struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);
+ xa_destroy(&cxl_nvd->pmem_regions);
kfree(cxl_nvd);
}
@@ -230,6 +231,7 @@ static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
dev = &cxl_nvd->dev;
cxl_nvd->cxlmd = cxlmd;
+ xa_init(&cxl_nvd->pmem_regions);
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_nvdimm_key);
device_set_pm_not_required(dev);
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index f680450f0b16..1164ad49f3d3 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -423,7 +423,7 @@ struct cxl_nvdimm {
struct device dev;
struct cxl_memdev *cxlmd;
struct cxl_nvdimm_bridge *bridge;
- struct cxl_pmem_region *region;
+ struct xarray pmem_regions;
};
struct cxl_pmem_region_mapping {
diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 0bac05d804bc..4c627d67281a 100644
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -30,17 +30,20 @@ static void unregister_nvdimm(void *nvdimm)
struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
struct cxl_nvdimm_bridge *cxl_nvb = cxl_nvd->bridge;
struct cxl_pmem_region *cxlr_pmem;
+ unsigned long index;
device_lock(&cxl_nvb->dev);
- cxlr_pmem = cxl_nvd->region;
dev_set_drvdata(&cxl_nvd->dev, NULL);
- cxl_nvd->region = NULL;
- device_unlock(&cxl_nvb->dev);
+ xa_for_each(&cxl_nvd->pmem_regions, index, cxlr_pmem) {
+ get_device(&cxlr_pmem->dev);
+ device_unlock(&cxl_nvb->dev);
- if (cxlr_pmem) {
device_release_driver(&cxlr_pmem->dev);
put_device(&cxlr_pmem->dev);
+
+ device_lock(&cxl_nvb->dev);
}
+ device_unlock(&cxl_nvb->dev);
nvdimm_delete(nvdimm);
cxl_nvd->bridge = NULL;
@@ -366,25 +369,49 @@ static int match_cxl_nvdimm(struct device *dev, void *data)
static void unregister_nvdimm_region(void *nd_region)
{
- struct cxl_nvdimm_bridge *cxl_nvb;
- struct cxl_pmem_region *cxlr_pmem;
+ nvdimm_region_delete(nd_region);
+}
+
+static int cxl_nvdimm_add_region(struct cxl_nvdimm *cxl_nvd,
+ struct cxl_pmem_region *cxlr_pmem)
+{
+ int rc;
+
+ rc = xa_insert(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem,
+ cxlr_pmem, GFP_KERNEL);
+ if (rc)
+ return rc;
+
+ get_device(&cxlr_pmem->dev);
+ return 0;
+}
+
+static void cxl_nvdimm_del_region(struct cxl_nvdimm *cxl_nvd,
+ struct cxl_pmem_region *cxlr_pmem)
+{
+ /*
+ * It is possible this is called without a corresponding
+ * cxl_nvdimm_add_region for @cxlr_pmem
+ */
+ cxlr_pmem = xa_erase(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem);
+ if (cxlr_pmem)
+ put_device(&cxlr_pmem->dev);
+}
+
+static void release_mappings(void *data)
+{
int i;
+ struct cxl_pmem_region *cxlr_pmem = data;
+ struct cxl_nvdimm_bridge *cxl_nvb = cxlr_pmem->bridge;
- cxlr_pmem = nd_region_provider_data(nd_region);
- cxl_nvb = cxlr_pmem->bridge;
device_lock(&cxl_nvb->dev);
for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
struct cxl_nvdimm *cxl_nvd = m->cxl_nvd;
- if (cxl_nvd->region) {
- put_device(&cxlr_pmem->dev);
- cxl_nvd->region = NULL;
- }
+ cxl_nvdimm_del_region(cxl_nvd, cxlr_pmem);
}
device_unlock(&cxl_nvb->dev);
-
- nvdimm_region_delete(nd_region);
}
static void cxlr_pmem_remove_resource(void *res)
@@ -422,7 +449,7 @@ static int cxl_pmem_region_probe(struct device *dev)
if (!cxl_nvb->nvdimm_bus) {
dev_dbg(dev, "nvdimm bus not found\n");
rc = -ENXIO;
- goto err;
+ goto out_nvb;
}
memset(&mappings, 0, sizeof(mappings));
@@ -431,7 +458,7 @@ static int cxl_pmem_region_probe(struct device *dev)
res = devm_kzalloc(dev, sizeof(*res), GFP_KERNEL);
if (!res) {
rc = -ENOMEM;
- goto err;
+ goto out_nvb;
}
res->name = "Persistent Memory";
@@ -442,11 +469,11 @@ static int cxl_pmem_region_probe(struct device *dev)
rc = insert_resource(&iomem_resource, res);
if (rc)
- goto err;
+ goto out_nvb;
rc = devm_add_action_or_reset(dev, cxlr_pmem_remove_resource, res);
if (rc)
- goto err;
+ goto out_nvb;
ndr_desc.res = res;
ndr_desc.provider_data = cxlr_pmem;
@@ -462,7 +489,7 @@ static int cxl_pmem_region_probe(struct device *dev)
nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
if (!nd_set) {
rc = -ENOMEM;
- goto err;
+ goto out_nvb;
}
ndr_desc.memregion = cxlr->id;
@@ -472,9 +499,13 @@ static int cxl_pmem_region_probe(struct device *dev)
info = kmalloc_array(cxlr_pmem->nr_mappings, sizeof(*info), GFP_KERNEL);
if (!info) {
rc = -ENOMEM;
- goto err;
+ goto out_nvb;
}
+ rc = devm_add_action_or_reset(dev, release_mappings, cxlr_pmem);
+ if (rc)
+ goto out_nvd;
+
for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
struct cxl_memdev *cxlmd = m->cxlmd;
@@ -486,7 +517,7 @@ static int cxl_pmem_region_probe(struct device *dev)
dev_dbg(dev, "[%d]: %s: no cxl_nvdimm found\n", i,
dev_name(&cxlmd->dev));
rc = -ENODEV;
- goto err;
+ goto out_nvd;
}
/* safe to drop ref now with bridge lock held */
@@ -498,10 +529,17 @@ static int cxl_pmem_region_probe(struct device *dev)
dev_dbg(dev, "[%d]: %s: no nvdimm found\n", i,
dev_name(&cxlmd->dev));
rc = -ENODEV;
- goto err;
+ goto out_nvd;
}
- cxl_nvd->region = cxlr_pmem;
- get_device(&cxlr_pmem->dev);
+
+ /*
+ * Pin the region per nvdimm device as those may be released
+ * out-of-order with respect to the region, and a single nvdimm
+ * maybe associated with multiple regions
+ */
+ rc = cxl_nvdimm_add_region(cxl_nvd, cxlr_pmem);
+ if (rc)
+ goto out_nvd;
m->cxl_nvd = cxl_nvd;
mappings[i] = (struct nd_mapping_desc) {
.nvdimm = nvdimm,
@@ -527,27 +565,18 @@ static int cxl_pmem_region_probe(struct device *dev)
nvdimm_pmem_region_create(cxl_nvb->nvdimm_bus, &ndr_desc);
if (!cxlr_pmem->nd_region) {
rc = -ENOMEM;
- goto err;
+ goto out_nvd;
}
rc = devm_add_action_or_reset(dev, unregister_nvdimm_region,
cxlr_pmem->nd_region);
-out:
+out_nvd:
kfree(info);
+out_nvb:
device_unlock(&cxl_nvb->dev);
put_device(&cxl_nvb->dev);
return rc;
-
-err:
- dev_dbg(dev, "failed to create nvdimm region\n");
- for (i--; i >= 0; i--) {
- nvdimm = mappings[i].nvdimm;
- cxl_nvd = nvdimm_provider_data(nvdimm);
- put_device(&cxl_nvd->region->dev);
- cxl_nvd->region = NULL;
- }
- goto out;
}
static struct cxl_driver cxl_pmem_region_driver = {