mm/mempolicy: Export memory policy symbols

KVM guest_memfd wants to implement support for NUMA policies just like
shmem already does using the shared policy infrastructure. As
guest_memfd currently resides in KVM module code, we have to export the
relevant symbols.

In the future, guest_memfd might be moved to core-mm, at which point the
symbols no longer would have to be exported. When/if that happens is
still unclear.

Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Tested-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/20250827175247.83322-6-shivankg@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index eb83cff7db8c35708296e5216e07783dc1bcb9b6..3d797d47a0402a1366942bc031399fc08c0f931f 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -354,6 +354,7 @@ struct mempolicy *get_task_policy(struct task_struct *p)
 
        return &default_policy;
 }
+EXPORT_SYMBOL_FOR_MODULES(get_task_policy, "kvm");
 
 static const struct mempolicy_operations {
        int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
@@ -487,6 +488,7 @@ void __mpol_put(struct mempolicy *pol)
                return;
        kmem_cache_free(policy_cache, pol);
 }
+EXPORT_SYMBOL_FOR_MODULES(__mpol_put, "kvm");
 
 static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
 {
@@ -2885,6 +2887,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
        read_unlock(&sp->lock);
        return pol;
 }
+EXPORT_SYMBOL_FOR_MODULES(mpol_shared_policy_lookup, "kvm");
 
 static void sp_free(struct sp_node *n)
 {
@@ -3170,6 +3173,7 @@ put_mpol:
                mpol_put(mpol); /* drop our incoming ref on sb mpol */
        }
 }
+EXPORT_SYMBOL_FOR_MODULES(mpol_shared_policy_init, "kvm");
 
 int mpol_set_shared_policy(struct shared_policy *sp,
                        struct vm_area_struct *vma, struct mempolicy *pol)
@@ -3188,6 +3192,7 @@ int mpol_set_shared_policy(struct shared_policy *sp,
                sp_free(new);
        return err;
 }
+EXPORT_SYMBOL_FOR_MODULES(mpol_set_shared_policy, "kvm");
 
 /* Free a backing policy store on inode delete. */
 void mpol_free_shared_policy(struct shared_policy *sp)
@@ -3206,6 +3211,7 @@ void mpol_free_shared_policy(struct shared_policy *sp)
        }
        write_unlock(&sp->lock);
 }
+EXPORT_SYMBOL_FOR_MODULES(mpol_free_shared_policy, "kvm");
 
 #ifdef CONFIG_NUMA_BALANCING
 static int __initdata numabalancing_override;