[Git][ghc/ghc][master] rts/CheckUnload: Reset old_objects if unload is skipped

[Marge Bot (@marge-bot)]

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC


Commits:
9efbc51f by Ben Gamari at 2024-12-10T14:03:48-05:00
rts/CheckUnload: Reset old_objects if unload is skipped

Previously `checkUnload` failed to reset `old_objects` when it decided
not to unload (e.g. due to heap profiling being enabled).

Fixes #24935.

- - - - -


1 changed file:

- rts/CheckUnload.c


Changes:

=====================================
rts/CheckUnload.c
=====================================
@@ -467,48 +467,44 @@ bool prepareUnloadCheck(void)
 
 void checkUnload(void)
 {
-    if (global_s_indices == NULL) {
-        return;
-    } else if (!safeToUnload()) {
-        return;
-    }
-
     // At this point we've marked all dynamically loaded static objects
     // (including their dependencies) during GC, but not the root set of object
     // code (loaded_objects). Mark the roots first, then unload any unmarked
     // objects.
 
-    OCSectionIndices *s_indices = global_s_indices;
-    ASSERT(s_indices->sorted);
+    if (global_s_indices != NULL && safeToUnload()) {
+        OCSectionIndices *s_indices = global_s_indices;
+        ASSERT(s_indices->sorted);
 
-    // Mark roots
-    for (ObjectCode *oc = loaded_objects; oc != NULL; oc = oc->next_loaded_object) {
-        markObjectLive(NULL, (W_)oc, NULL);
-    }
+        // Mark roots
+        for (ObjectCode *oc = loaded_objects; oc != NULL; oc = oc->next_loaded_object) {
+            markObjectLive(NULL, (W_)oc, NULL);
+        }
 
-    // Free unmarked objects
-    ObjectCode *next = NULL;
-    for (ObjectCode *oc = old_objects; oc != NULL; oc = next) {
-        next = oc->next;
-        ASSERT(oc->status == OBJECT_UNLOADED);
-
-        // Symbols should be removed by unloadObj_.
-        // NB (osa): If this assertion doesn't hold then freeObjectCode below
-        // will corrupt symhash as keys of that table live in ObjectCodes. If
-        // you see a segfault in a hash table operation in linker (in non-debug
-        // RTS) then it's probably because this assertion did not hold.
-        ASSERT(oc->symbols == NULL);
-
-        if (oc->unloadable) {
-            removeOCSectionIndices(s_indices, oc);
-            freeObjectCode(oc);
-            n_unloaded_objects -= 1;
-        } else {
-            // If we don't have enough information to
-            // accurately determine the reachability of
-            // the object then hold onto it.
-            oc->next = objects;
-            objects = oc;
+        // Free unmarked objects
+        ObjectCode *next = NULL;
+        for (ObjectCode *oc = old_objects; oc != NULL; oc = next) {
+            next = oc->next;
+            ASSERT(oc->status == OBJECT_UNLOADED);
+
+            // Symbols should be removed by unloadObj_.
+            // NB (osa): If this assertion doesn't hold then freeObjectCode below
+            // will corrupt symhash as keys of that table live in ObjectCodes. If
+            // you see a segfault in a hash table operation in linker (in non-debug
+            // RTS) then it's probably because this assertion did not hold.
+            ASSERT(oc->symbols == NULL);
+
+            if (oc->unloadable) {
+                removeOCSectionIndices(s_indices, oc);
+                freeObjectCode(oc);
+                n_unloaded_objects -= 1;
+            } else {
+                // If we don't have enough information to
+                // accurately determine the reachability of
+                // the object then hold onto it.
+                oc->next = objects;
+                objects = oc;
+            }
         }
     }
 



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9efbc51f99118e8f9c3abf2bcb6dc3295893ded6

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9efbc51f99118e8f9c3abf2bcb6dc3295893ded6
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