From d357dd8ad2f154376e5cb930284e7bf4fe21ffaa Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 30 Apr 2024 14:59:00 -0700 Subject: cxl/region: Convert cxl_pmem_region_alloc to scope-based resource management 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 Reported-by: Jonathan Cameron 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 Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/171451430965.1147997.15782562063090960666.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang --- drivers/cxl/core/region.c | 43 +++++++++++++++++-------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 29b0b8a52d3d..00a9f0eef8dd 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -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 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; @@ -2853,11 +2848,8 @@ 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; @@ -2868,18 +2860,16 @@ 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) @@ -2996,9 +2986,10 @@ 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; -- cgit v1.2.3