iASL: Fix unaligned accesses to local cache allocations

Despite the documentation talking of strings, and the various constants
and variables used in the function also doing so, UtLocalCacheCalloc
gets used for things other than strings, such as FlInitOneFile using it
to allocate an ASL_GLOBAL_FILE_NODE. The easiest way to fix that for a
bump the pointer allocator is to just round up every allocation's size;
there are more complex alternatives, as allocations smaller than the
maximum native alignment only need to be rounded up to the next power of
two, but optimising for that case seems unnecessarily complicated.

It might make sense to split this into a string allocator and a separate
generic object allocator (to complement the existing specific object
allocators) to ensure strings can still be packed tightly in memory, but
that is a more invasive change that may not be worth it for the small
decrease in memory footprint.

1 files changed, 5 insertions, 0 deletions

diff --git a/source/compiler/aslcache.c b/source/compiler/aslcache.c
index 51e6f4c46..05ae19b74 100644
--- a/source/compiler/aslcache.c
+++ b/source/compiler/aslcache.c
@@ -183,6 +183,11 @@ UtLocalCacheCalloc (
     UINT32                  CacheSize = ASL_STRING_CACHE_SIZE;
 
 
+#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
+    /* Used for objects other than strings, so keep allocations aligned */
+    Length = ACPI_ROUND_UP_TO_NATIVE_WORD (Length);
+#endif
+
     if (Length > CacheSize)
     {
         CacheSize = Length;