diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2021-04-01 07:33:25 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2021-04-06 11:41:30 -0700 |
| commit | 1c3333a28d4532cfc37d4d25bfc76654a0c76643 (patch) | |
| tree | 67fd629f9d6b50214644239e585e84fddacda935 /drivers | |
| parent | 5877515912cc4f0d67071b7cee15076ebef24708 (diff) | |
cxl/mem: Do not rely on device_add() side effects for dev_set_name() failures
While device_add() will happen to catch dev_set_name() failures it is a
broken pattern to follow given that the core may try to fall back to a
different name.
Add explicit checking for dev_set_name() failures to be cleaned up by
put_device(). Skip cdev_device_add() and proceed directly to
put_device() if the name set fails.
This type of bug is easier to see if 'alloc' is split from 'add'
operations that require put_device() on failure. So cxl_memdev_alloc()
is split out as a result.
Fixes: b39cb1052a5c ("cxl/mem: Register CXL memX devices")
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/161728760514.2474381.1163928273337158134.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cxl/mem.c | 39 |
1 files changed, 29 insertions, 10 deletions
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 438f0861c46c..da93b633531f 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -1180,7 +1180,7 @@ static void cxl_memdev_unregister(void *_cxlmd) put_device(dev); } -static int cxl_mem_add_memdev(struct cxl_mem *cxlm) +static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm) { struct pci_dev *pdev = cxlm->pdev; struct cxl_memdev *cxlmd; @@ -1190,11 +1190,11 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) cxlmd = kzalloc(sizeof(*cxlmd), GFP_KERNEL); if (!cxlmd) - return -ENOMEM; + return ERR_PTR(-ENOMEM); rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL); if (rc < 0) - goto err_id; + goto err; cxlmd->id = rc; dev = &cxlmd->dev; @@ -1203,10 +1203,31 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) dev->bus = &cxl_bus_type; dev->devt = MKDEV(cxl_mem_major, cxlmd->id); dev->type = &cxl_memdev_type; - dev_set_name(dev, "mem%d", cxlmd->id); cdev = &cxlmd->cdev; cdev_init(cdev, &cxl_memdev_fops); + return cxlmd; + +err: + kfree(cxlmd); + return ERR_PTR(rc); +} + +static int cxl_mem_add_memdev(struct cxl_mem *cxlm) +{ + struct cxl_memdev *cxlmd; + struct device *dev; + struct cdev *cdev; + int rc; + + cxlmd = cxl_memdev_alloc(cxlm); + if (IS_ERR(cxlmd)) + return PTR_ERR(cxlmd); + + dev = &cxlmd->dev; + rc = dev_set_name(dev, "mem%d", cxlmd->id); + if (rc) + goto err; /* * Activate ioctl operations, no cxl_memdev_rwsem manipulation @@ -1214,23 +1235,21 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) */ cxlmd->cxlm = cxlm; + cdev = &cxlmd->cdev; rc = cdev_device_add(cdev, dev); if (rc) - goto err_add; + goto err; return devm_add_action_or_reset(dev->parent, cxl_memdev_unregister, cxlmd); -err_add: +err: /* * The cdev was briefly live, shutdown any ioctl operations that * saw that state. */ cxl_memdev_shutdown(cxlmd); - ida_free(&cxl_memdev_ida, cxlmd->id); -err_id: - kfree(cxlmd); - + put_device(dev); return rc; } |