diff options
| author | Gregory Price <gourry@gourry.net> | 2026-02-11 14:22:27 -0500 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2026-02-23 09:03:44 -0700 |
| commit | 318c58852e686c009825ae8c071080b9ccdd2af0 (patch) | |
| tree | ac34da4647343e08057b8a360bc1207e72c8bf8b /drivers/cxl | |
| parent | 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (diff) | |
| download | linux-next-318c58852e686c009825ae8c071080b9ccdd2af0.tar.gz linux-next-318c58852e686c009825ae8c071080b9ccdd2af0.zip | |
cxl/memdev: fix deadlock in cxl_memdev_autoremove() on attach failure
cxl_memdev_autoremove() takes device_lock(&cxlmd->dev) via guard(device)
and then calls cxl_memdev_unregister() when the attach callback was
provided but cxl_mem_probe() failed to bind.
cxl_memdev_unregister() calls
cdev_device_del()
device_del()
bus_remove_device()
device_release_driver()
This path is reached when a driver uses the @attach parameter to
devm_cxl_add_memdev() and the CXL topology fails to enumerate (e.g.
DVSEC range registers decode outside platform-defined CXL ranges,
causing the endpoint port probe to fail).
Add cxl_memdev_attach_failed() to set the scope of the check correctly.
Reported-by: kreview-c94b85d6d2
Fixes: 29317f8dc6ed ("cxl/mem: Introduce cxl_memdev_attach for CXL-dependent operation")
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://patch.msgid.link/20260211192228.2148713-1-gourry@gourry.net
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/core/memdev.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index f547d8ac34c7..273c22118d3d 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -1089,10 +1089,8 @@ static int cxlmd_add(struct cxl_memdev *cxlmd, struct cxl_dev_state *cxlds) DEFINE_FREE(put_cxlmd, struct cxl_memdev *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev)) -static struct cxl_memdev *cxl_memdev_autoremove(struct cxl_memdev *cxlmd) +static bool cxl_memdev_attach_failed(struct cxl_memdev *cxlmd) { - int rc; - /* * If @attach is provided fail if the driver is not attached upon * return. Note that failure here could be the result of a race to @@ -1100,7 +1098,14 @@ static struct cxl_memdev *cxl_memdev_autoremove(struct cxl_memdev *cxlmd) * succeeded and then cxl_mem unbound before the lock is acquired. */ guard(device)(&cxlmd->dev); - if (cxlmd->attach && !cxlmd->dev.driver) { + return (cxlmd->attach && !cxlmd->dev.driver); +} + +static struct cxl_memdev *cxl_memdev_autoremove(struct cxl_memdev *cxlmd) +{ + int rc; + + if (cxl_memdev_attach_failed(cxlmd)) { cxl_memdev_unregister(cxlmd); return ERR_PTR(-ENXIO); } |