6.9-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams dan.j.williams@intel.com
[ Upstream commit d357dd8ad2f154376e5cb930284e7bf4fe21ffaa ]
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@dw... Signed-off-by: Dave Jiang dave.jiang@intel.com Stable-dep-of: 84ec985944ef ("cxl/mem: Fix no cxl_nvd during pmem region auto-assembling") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 18b95149640b6..bcb30e04e0963 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;