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authorChristoph Hellwig <hch@lst.de>2020-03-16 20:32:13 +0100
committerJason Gunthorpe <jgg@mellanox.com>2020-03-26 14:33:37 -0300
commitf894ddd5ff01d3bb48faf4dc533536bf5269c17a (patch)
tree6e62359994be7d1e61aab32864b6cc399cbb09e5
parent5a0c38d307afde167175602aa52ca4e6c5c42c44 (diff)
memremap: add an owner field to struct dev_pagemap
Add a new opaque owner field to struct dev_pagemap, which will allow the hmm and migrate_vma code to identify who owns ZONE_DEVICE memory, and refuse to work on mappings not owned by the calling entity. Link: https://lore.kernel.org/r/20200316193216.920734-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Tested-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
-rw-r--r--arch/powerpc/kvm/book3s_hv_uvmem.c2
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_dmem.c1
-rw-r--r--include/linux/memremap.h4
-rw-r--r--mm/memremap.c4
4 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 79b1202b1c62..67fefb03b9b7 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -779,6 +779,8 @@ int kvmppc_uvmem_init(void)
kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE;
kvmppc_uvmem_pgmap.res = *res;
kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops;
+ /* just one global instance: */
+ kvmppc_uvmem_pgmap.owner = &kvmppc_uvmem_pgmap;
addr = memremap_pages(&kvmppc_uvmem_pgmap, NUMA_NO_NODE);
if (IS_ERR(addr)) {
ret = PTR_ERR(addr);
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 0ad5d87b5a8e..a4682272586e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -526,6 +526,7 @@ nouveau_dmem_init(struct nouveau_drm *drm)
drm->dmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
drm->dmem->pagemap.res = *res;
drm->dmem->pagemap.ops = &nouveau_dmem_pagemap_ops;
+ drm->dmem->pagemap.owner = drm->dev;
if (IS_ERR(devm_memremap_pages(device, &drm->dmem->pagemap)))
goto out_free;
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 6fefb09af7c3..60d97e8fd3c0 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -103,6 +103,9 @@ struct dev_pagemap_ops {
* @type: memory type: see MEMORY_* in memory_hotplug.h
* @flags: PGMAP_* flags to specify defailed behavior
* @ops: method table
+ * @owner: an opaque pointer identifying the entity that manages this
+ * instance. Used by various helpers to make sure that no
+ * foreign ZONE_DEVICE memory is accessed.
*/
struct dev_pagemap {
struct vmem_altmap altmap;
@@ -113,6 +116,7 @@ struct dev_pagemap {
enum memory_type type;
unsigned int flags;
const struct dev_pagemap_ops *ops;
+ void *owner;
};
static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
diff --git a/mm/memremap.c b/mm/memremap.c
index 09b5b7adc773..9b2c97ceb775 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -181,6 +181,10 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
WARN(1, "Missing migrate_to_ram method\n");
return ERR_PTR(-EINVAL);
}
+ if (!pgmap->owner) {
+ WARN(1, "Missing owner\n");
+ return ERR_PTR(-EINVAL);
+ }
break;
case MEMORY_DEVICE_FS_DAX:
if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||