| Message ID | 166752183055.947915.17681995648556534844.stgit@dwillia2-xfh.jf.intel.com |
|---|---|
| State | Accepted |
| Commit | 9ef13807cf9ab9a5e32dd26070637de998e5fc07 |
| Headers | show |
| Series | CXL region creation fixes for 6.1 | expand |
On Thu, 2022-11-03 at 17:30 -0700, Dan Williams wrote: > When a region is deleted any targets that have been previously assigned > to that region hold references to it. Trigger those references to > drop by detaching all targets at unregister_region() time. > > Otherwise that region object will leak as userspace has lost the ability > to detach targets once region sysfs is torn down. > > Cc: <stable@vger.kernel.org> > Fixes: b9686e8c8e39 ("cxl/region: Enable the assignment of endpoint decoders to regions") > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/cxl/core/region.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) Looks good, Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index d26ca7a6beae..c52465e09f26 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -1557,8 +1557,19 @@ static struct cxl_region *to_cxl_region(struct device *dev) > static void unregister_region(void *dev) > { > struct cxl_region *cxlr = to_cxl_region(dev); > + struct cxl_region_params *p = &cxlr->params; > + int i; > > device_del(dev); > + > + /* > + * Now that region sysfs is shutdown, the parameter block is now > + * read-only, so no need to hold the region rwsem to access the > + * region parameters. > + */ > + for (i = 0; i < p->interleave_ways; i++) > + detach_target(cxlr, i); > + > cxl_region_iomem_release(cxlr); > put_device(dev); > } >
On 11/3/2022 5:30 PM, Dan Williams wrote: > When a region is deleted any targets that have been previously assigned > to that region hold references to it. Trigger those references to > drop by detaching all targets at unregister_region() time. > > Otherwise that region object will leak as userspace has lost the ability > to detach targets once region sysfs is torn down. > > Cc: <stable@vger.kernel.org> > Fixes: b9686e8c8e39 ("cxl/region: Enable the assignment of endpoint decoders to regions") > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/cxl/core/region.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index d26ca7a6beae..c52465e09f26 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -1557,8 +1557,19 @@ static struct cxl_region *to_cxl_region(struct device *dev) > static void unregister_region(void *dev) > { > struct cxl_region *cxlr = to_cxl_region(dev); > + struct cxl_region_params *p = &cxlr->params; > + int i; > > device_del(dev); > + > + /* > + * Now that region sysfs is shutdown, the parameter block is now > + * read-only, so no need to hold the region rwsem to access the > + * region parameters. > + */ > + for (i = 0; i < p->interleave_ways; i++) > + detach_target(cxlr, i); > + > cxl_region_iomem_release(cxlr); > put_device(dev); > } >
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index d26ca7a6beae..c52465e09f26 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1557,8 +1557,19 @@ static struct cxl_region *to_cxl_region(struct device *dev) static void unregister_region(void *dev) { struct cxl_region *cxlr = to_cxl_region(dev); + struct cxl_region_params *p = &cxlr->params; + int i; device_del(dev); + + /* + * Now that region sysfs is shutdown, the parameter block is now + * read-only, so no need to hold the region rwsem to access the + * region parameters. + */ + for (i = 0; i < p->interleave_ways; i++) + detach_target(cxlr, i); + cxl_region_iomem_release(cxlr); put_device(dev); }
When a region is deleted any targets that have been previously assigned to that region hold references to it. Trigger those references to drop by detaching all targets at unregister_region() time. Otherwise that region object will leak as userspace has lost the ability to detach targets once region sysfs is torn down. Cc: <stable@vger.kernel.org> Fixes: b9686e8c8e39 ("cxl/region: Enable the assignment of endpoint decoders to regions") Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/cxl/core/region.c | 11 +++++++++++ 1 file changed, 11 insertions(+)