diff options
author | Huang Ying <ying.huang@intel.com> | 2024-06-18 10:46:37 +0200 |
---|---|---|
committer | Dave Jiang <dave.jiang@intel.com> | 2024-07-02 21:52:26 +0200 |
commit | a3483ee7e6a7f2d12b5950246f4e0ef94f4a5df0 (patch) | |
tree | b5d1e11185db9612d6bad9f83d6ec49fb27416af /drivers | |
parent | cxl: add missing MODULE_DESCRIPTION() macros (diff) | |
download | linux-a3483ee7e6a7f2d12b5950246f4e0ef94f4a5df0.tar.xz linux-a3483ee7e6a7f2d12b5950246f4e0ef94f4a5df0.zip |
cxl/region: Fix a race condition in memory hotplug notifier
In the memory hotplug notifier function of the CXL region,
cxl_region_perf_attrs_callback(), the node ID is obtained by checking
the host address range of the region. However, the address range
information is not available when the region is registered in
devm_cxl_add_region(). Additionally, this information may be removed
or added under the protection of cxl_region_rwsem during runtime. If
the memory notifier is called for nodes other than that backed by the
region, a race condition may occur, potentially leading to a NULL
dereference or an invalid address range.
The race condition is addressed by checking the availability of the
address range information under the protection of cxl_region_rwsem. To
enhance code readability and use guard(), the relevant code has been
moved into a newly added function: cxl_region_nid().
Fixes: 067353a46d8c ("cxl/region: Add memory hotplug notifier for cxl region")
Signed-off-by: Huang, Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20240618084639.1419629-2-ying.huang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/cxl/core/region.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 3c2b6144be23..51aeef2c012c 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2304,14 +2304,25 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid) return true; } +static int cxl_region_nid(struct cxl_region *cxlr) +{ + struct cxl_region_params *p = &cxlr->params; + struct cxl_endpoint_decoder *cxled; + struct cxl_decoder *cxld; + + guard(rwsem_read)(&cxl_region_rwsem); + cxled = p->targets[0]; + if (!cxled) + return NUMA_NO_NODE; + cxld = &cxled->cxld; + return phys_to_target_node(cxld->hpa_range.start); +} + static int cxl_region_perf_attrs_callback(struct notifier_block *nb, unsigned long action, void *arg) { struct cxl_region *cxlr = container_of(nb, struct cxl_region, memory_notifier); - struct cxl_region_params *p = &cxlr->params; - struct cxl_endpoint_decoder *cxled = p->targets[0]; - struct cxl_decoder *cxld = &cxled->cxld; struct memory_notify *mnb = arg; int nid = mnb->status_change_nid; int region_nid; @@ -2319,7 +2330,7 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb, if (nid == NUMA_NO_NODE || action != MEM_ONLINE) return NOTIFY_DONE; - region_nid = phys_to_target_node(cxld->hpa_range.start); + region_nid = cxl_region_nid(cxlr); if (nid != region_nid) return NOTIFY_DONE; |