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cxl/region: Convert cxl_pmem_region_alloc to scope-based resource management

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A recent bugfix to cxl_pmem_region_alloc() to fix an
error-unwind-memleak [1], highlighted a use case for scope-based resource
management.

Delete the goto for releasing @cxl_region_rwsem, and return error codes
directly from error condition paths.

The caller, devm_cxl_add_pmem_region(), is no longer given @cxlr_pmem
directly it must retrieve it from @cxlr->cxlr_pmem. This retrieval from
@cxlr was already in place for @cxlr->cxl_nvb, and converting
cxl_pmem_region_alloc() to return an int makes it less awkward to handle
no_free_ptr().

Cc: Li Zhijian <lizhijian@fujitsu.com>
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: http://lore.kernel.org/r/20240430174540.000039ce@Huawei.com
Link: http://lore.kernel.org/r/20240428030748.318985-1-lizhijian@fujitsu.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/171451430965.1147997.15782562063090960666.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
This commit is contained in:
Dan Williams
2024-04-30 14:59:00 -07:00
committed by Dave Jiang
parent e4ff70a8e3
commit d357dd8ad2
1 changed files with 17 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/cxl/core/region.c
+17 -26
View File
@@ -2816,26 +2816,21 @@ u64 cxl_trace_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
static struct lock_class_key cxl_pmem_region_key; static struct lock_class_key cxl_pmem_region_key;
static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr) static int cxl_pmem_region_alloc(struct cxl_region *cxlr)
{ {
struct cxl_region_params *p = &cxlr->params; struct cxl_region_params *p = &cxlr->params;
struct cxl_nvdimm_bridge *cxl_nvb; struct cxl_nvdimm_bridge *cxl_nvb;
struct cxl_pmem_region *cxlr_pmem;
struct device *dev; struct device *dev;
int i; int i;
down_read(&cxl_region_rwsem); guard(rwsem_read)(&cxl_region_rwsem);
if (p->state != CXL_CONFIG_COMMIT) { if (p->state != CXL_CONFIG_COMMIT)
cxlr_pmem = ERR_PTR(-ENXIO); return -ENXIO;
goto out;
}
cxlr_pmem = kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets), struct cxl_pmem_region *cxlr_pmem __free(kfree) =
GFP_KERNEL); kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets), GFP_KERNEL);
if (!cxlr_pmem) { if (!cxlr_pmem)
cxlr_pmem = ERR_PTR(-ENOMEM); return -ENOMEM;
goto out;
}
cxlr_pmem->hpa_range.start = p->res->start; cxlr_pmem->hpa_range.start = p->res->start;
cxlr_pmem->hpa_range.end = p->res->end; cxlr_pmem->hpa_range.end = p->res->end;
@@ -2853,11 +2848,8 @@ static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)
*/ */
if (i == 0) { if (i == 0) {
cxl_nvb = cxl_find_nvdimm_bridge(cxlmd); cxl_nvb = cxl_find_nvdimm_bridge(cxlmd);
if (!cxl_nvb) { if (!cxl_nvb)
kfree(cxlr_pmem); return -ENODEV;
cxlr_pmem = ERR_PTR(-ENODEV);
goto out;
}
cxlr->cxl_nvb = cxl_nvb; cxlr->cxl_nvb = cxl_nvb;
} }
m->cxlmd = cxlmd; m->cxlmd = cxlmd;
@@ -2868,18 +2860,16 @@ static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)
} }
dev = &cxlr_pmem->dev; dev = &cxlr_pmem->dev;
cxlr_pmem->cxlr = cxlr;
cxlr->cxlr_pmem = cxlr_pmem;
device_initialize(dev); device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_pmem_region_key); lockdep_set_class(&dev->mutex, &cxl_pmem_region_key);
device_set_pm_not_required(dev); device_set_pm_not_required(dev);
dev->parent = &cxlr->dev; dev->parent = &cxlr->dev;
dev->bus = &cxl_bus_type; dev->bus = &cxl_bus_type;
dev->type = &cxl_pmem_region_type; dev->type = &cxl_pmem_region_type;
out: cxlr_pmem->cxlr = cxlr;
up_read(&cxl_region_rwsem); cxlr->cxlr_pmem = no_free_ptr(cxlr_pmem);
return cxlr_pmem; return 0;
} }
static void cxl_dax_region_release(struct device *dev) static void cxl_dax_region_release(struct device *dev)
@@ -2996,9 +2986,10 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
struct device *dev; struct device *dev;
int rc; int rc;
cxlr_pmem = cxl_pmem_region_alloc(cxlr); rc = cxl_pmem_region_alloc(cxlr);
if (IS_ERR(cxlr_pmem)) if (rc)
return PTR_ERR(cxlr_pmem); return rc;
cxlr_pmem = cxlr->cxlr_pmem;
cxl_nvb = cxlr->cxl_nvb; cxl_nvb = cxlr->cxl_nvb;
dev = &cxlr_pmem->dev; dev = &cxlr_pmem->dev;