From: Dan Williams <dan.j.williams@intel.com>
To: dave.jiang@intel.com
Cc: Li Zhijian <lizhijian@fujitsu.com>,
Jonathan Cameron <Jonathan.Cameron@Huawei.com>,
linux-cxl@vger.kernel.org
Subject: [PATCH] cxl/region: Convert cxl_pmem_region_alloc to scope-based resource management
Date: Tue, 30 Apr 2024 14:59:00 -0700 [thread overview]
Message-ID: <171451430965.1147997.15782562063090960666.stgit@dwillia2-xfh.jf.intel.com> (raw)
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>
---
Hey Dave, this applies on top of Li's fix.
drivers/cxl/core/region.c | 43 +++++++++++++++++--------------------------
1 file changed, 17 insertions(+), 26 deletions(-)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 812b2948b6c6..e0577d99c4db 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2681,26 +2681,21 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port)
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_nvdimm_bridge *cxl_nvb;
- struct cxl_pmem_region *cxlr_pmem;
struct device *dev;
int i;
- down_read(&cxl_region_rwsem);
- if (p->state != CXL_CONFIG_COMMIT) {
- cxlr_pmem = ERR_PTR(-ENXIO);
- goto out;
- }
+ guard(rwsem_read)(&cxl_region_rwsem);
+ if (p->state != CXL_CONFIG_COMMIT)
+ return -ENXIO;
- cxlr_pmem = kzalloc(struct_size(cxlr_pmem, mapping, p->nr_targets),
- GFP_KERNEL);
- if (!cxlr_pmem) {
- cxlr_pmem = ERR_PTR(-ENOMEM);
- goto out;
- }
+ struct cxl_pmem_region *cxlr_pmem __free(kfree) = kzalloc(
+ struct_size(cxlr_pmem, mapping, p->nr_targets), GFP_KERNEL);
+ if (!cxlr_pmem)
+ return -ENOMEM;
cxlr_pmem->hpa_range.start = p->res->start;
cxlr_pmem->hpa_range.end = p->res->end;
@@ -2718,11 +2713,8 @@ static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)
*/
if (i == 0) {
cxl_nvb = cxl_find_nvdimm_bridge(cxlmd);
- if (!cxl_nvb) {
- kfree(cxlr_pmem);
- cxlr_pmem = ERR_PTR(-ENODEV);
- goto out;
- }
+ if (!cxl_nvb)
+ return -ENODEV;
cxlr->cxl_nvb = cxl_nvb;
}
m->cxlmd = cxlmd;
@@ -2733,18 +2725,16 @@ static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr)
}
dev = &cxlr_pmem->dev;
- cxlr_pmem->cxlr = cxlr;
- cxlr->cxlr_pmem = cxlr_pmem;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_pmem_region_key);
device_set_pm_not_required(dev);
dev->parent = &cxlr->dev;
dev->bus = &cxl_bus_type;
dev->type = &cxl_pmem_region_type;
-out:
- up_read(&cxl_region_rwsem);
+ cxlr_pmem->cxlr = cxlr;
+ cxlr->cxlr_pmem = no_free_ptr(cxlr_pmem);
- return cxlr_pmem;
+ return 0;
}
static void cxl_dax_region_release(struct device *dev)
@@ -2861,9 +2851,10 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
struct device *dev;
int rc;
- cxlr_pmem = cxl_pmem_region_alloc(cxlr);
- if (IS_ERR(cxlr_pmem))
- return PTR_ERR(cxlr_pmem);
+ rc = cxl_pmem_region_alloc(cxlr);
+ if (rc)
+ return rc;
+ cxlr_pmem = cxlr->cxlr_pmem;
cxl_nvb = cxlr->cxl_nvb;
dev = &cxlr_pmem->dev;
next reply other threads:[~2024-04-30 21:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-30 21:59 Dan Williams [this message]
2024-04-30 22:50 ` [PATCH] cxl/region: Convert cxl_pmem_region_alloc to scope-based resource management fan
2024-05-01 12:02 ` Jonathan Cameron
2024-05-01 23:27 ` Dan Williams
2024-05-09 7:04 ` Zhijian Li (Fujitsu)
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