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| author | Ben Gamari <ben@smart-cactus.org> | 2022-05-23 23:00:32 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-06-18 10:42:54 -0400 |
| commit | cadd775397a88889bb6be6aca34469eea8ba17ec (patch) | |
| tree | 6dc512f753e2b800b960e7ca315c31b27c09ec2a /rts | |
| parent | 229d741f9907f0a07c475291fe3b1dbfcfea7aab (diff) | |
| download | haskell-cadd775397a88889bb6be6aca34469eea8ba17ec.tar.gz | |
ghc-heap: Don't Box NULL pointers
Previously we could construct a `Box` of a NULL pointer from the `link`
field of `StgWeak`. Now we take care to avoid ever introducing such
pointers in `collect_pointers` and ensure that the `link` field is
represented as a `Maybe` in the `Closure` type.
Fixes #21622
Diffstat (limited to 'rts')
| -rw-r--r-- | rts/Heap.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/rts/Heap.c b/rts/Heap.c index 09beb9a8d2..0594a46b0b 100644 --- a/rts/Heap.c +++ b/rts/Heap.c @@ -224,13 +224,18 @@ StgWord collect_pointers(StgClosure *closure, StgClosure *ptrs[]) { ptrs[nptrs++] = (StgClosure *)((StgTSO *)closure)->bq; break; - case WEAK: - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->cfinalizers; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->key; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->value; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->finalizer; - ptrs[nptrs++] = (StgClosure *)((StgWeak *)closure)->link; + case WEAK: { + StgWeak *w = (StgWeak *)closure; + ptrs[nptrs++] = (StgClosure *) w->cfinalizers; + ptrs[nptrs++] = (StgClosure *) w->key; + ptrs[nptrs++] = (StgClosure *) w->value; + ptrs[nptrs++] = (StgClosure *) w->finalizer; + // link may be NULL which is not a valid GC pointer + if (w->link) { + ptrs[nptrs++] = (StgClosure *) w->link; + } break; + } default: fprintf(stderr,"closurePtrs: Cannot handle type %s yet\n", |