File 6571ca95-fix-sched_move_domain.patch of Package xen

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File 6571ca95-fix-sched_move_domain.patch of Package xen (Revision e7ae745b4417e790a0f7f091589af938)

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# Commit 23792cc0f22cff4e106d838b83aa9ae1cb6ffaf4
# Date 2023-12-07 13:37:25 +0000
# Author Juergen Gross <jgross@suse.com>
# Committer George Dunlap <george.dunlap@cloud.com>
xen/sched: fix sched_move_domain()

Do cleanup in sched_move_domain() in a dedicated service function,
which is called either in error case with newly allocated data, or in
success case with the old data to be freed.

This will at once fix some subtle bugs which sneaked in due to
forgetting to overwrite some pointers in the error case.

Fixes: 70fadc41635b ("xen/cpupool: support moving domain between cpupools with different granularity")
Reported-by: René Winther Højgaard <renewin@proton.me>
Initial-fix-by: Jan Beulich <jbeulich@suse.com>
Initial-fix-by: George Dunlap <george.dunlap@cloud.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>

--- a/xen/common/sched/core.c
+++ b/xen/common/sched/core.c
@@ -647,6 +647,24 @@ static void sched_move_irqs(const struct
         vcpu_move_irqs(v);
 }
 
+static void sched_move_domain_cleanup(const struct scheduler *ops,
+                                      struct sched_unit *units,
+                                      void *domdata)
+{
+    struct sched_unit *unit, *old_unit;
+
+    for ( unit = units; unit; )
+    {
+        if ( unit->priv )
+            sched_free_udata(ops, unit->priv);
+        old_unit = unit;
+        unit = unit->next_in_list;
+        xfree(old_unit);
+    }
+
+    sched_free_domdata(ops, domdata);
+}
+
 /*
  * Move a domain from one cpupool to another.
  *
@@ -686,7 +704,6 @@ int sched_move_domain(struct domain *d,
     void *old_domdata;
     unsigned int gran = cpupool_get_granularity(c);
     unsigned int n_units = d->vcpu[0] ? DIV_ROUND_UP(d->max_vcpus, gran) : 0;
-    int ret = 0;
 
     for_each_vcpu ( d, v )
     {
@@ -699,8 +716,9 @@ int sched_move_domain(struct domain *d,
     domdata = sched_alloc_domdata(c->sched, d);
     if ( IS_ERR(domdata) )
     {
-        ret = PTR_ERR(domdata);
-        goto out;
+        rcu_read_unlock(&sched_res_rculock);
+
+        return PTR_ERR(domdata);
     }
 
     for ( unit_idx = 0; unit_idx < n_units; unit_idx++ )
@@ -718,10 +736,10 @@ int sched_move_domain(struct domain *d,
 
         if ( !unit || !unit->priv )
         {
-            old_units = new_units;
-            old_domdata = domdata;
-            ret = -ENOMEM;
-            goto out_free;
+            sched_move_domain_cleanup(c->sched, new_units, domdata);
+            rcu_read_unlock(&sched_res_rculock);
+
+            return -ENOMEM;
         }
 
         unit_ptr = &unit->next_in_list;
@@ -808,22 +826,11 @@ int sched_move_domain(struct domain *d,
 
     domain_unpause(d);
 
- out_free:
-    for ( unit = old_units; unit; )
-    {
-        if ( unit->priv )
-            sched_free_udata(c->sched, unit->priv);
-        old_unit = unit;
-        unit = unit->next_in_list;
-        xfree(old_unit);
-    }
-
-    sched_free_domdata(old_ops, old_domdata);
+    sched_move_domain_cleanup(old_ops, old_units, old_domdata);
 
- out:
     rcu_read_unlock(&sched_res_rculock);
 
-    return ret;
+    return 0;
 }
 
 void sched_destroy_vcpu(struct vcpu *v)

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File 6571ca95-fix-sched_move_domain.patch of Package xen (Revision e7ae745b4417e790a0f7f091589af938)

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