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charset=us-ascii Content-Disposition: inline In-Reply-To: <171451430965.1147997.15782562063090960666.stgit@dwillia2-xfh.jf.intel.com> On Tue, Apr 30, 2024 at 02:59:00PM -0700, Dan Williams wrote: > 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 > --- > 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; > LGTM. Fan