diff options
Diffstat (limited to 'src/backend/utils/mmgr/alignedalloc.c')
| -rw-r--r-- | src/backend/utils/mmgr/alignedalloc.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/src/backend/utils/mmgr/alignedalloc.c b/src/backend/utils/mmgr/alignedalloc.c index 85aee389d6b..7eea695de62 100644 --- a/src/backend/utils/mmgr/alignedalloc.c +++ b/src/backend/utils/mmgr/alignedalloc.c @@ -45,6 +45,7 @@ AlignedAllocFree(void *pointer) GetMemoryChunkContext(unaligned)->name, chunk); #endif + /* Recursively pfree the unaligned chunk */ pfree(unaligned); } @@ -96,18 +97,32 @@ AlignedAllocRealloc(void *pointer, Size size, int flags) Assert(old_size >= redirchunk->requested_size); #endif + /* + * To keep things simple, we always allocate a new aligned chunk and copy + * data into it. Because of the above inaccuracy, this may end in copying + * more data than was in the original allocation request size, but that + * should be OK. + */ ctx = GetMemoryChunkContext(unaligned); newptr = MemoryContextAllocAligned(ctx, size, alignto, flags); - /* - * We may memcpy beyond the end of the original allocation request size, - * so we must mark the entire allocation as defined. - */ - if (likely(newptr != NULL)) + /* Cope cleanly with OOM */ + if (unlikely(newptr == NULL)) { - VALGRIND_MAKE_MEM_DEFINED(pointer, old_size); - memcpy(newptr, pointer, Min(size, old_size)); + VALGRIND_MAKE_MEM_NOACCESS(redirchunk, sizeof(MemoryChunk)); + return MemoryContextAllocationFailure(ctx, size, flags); } + + /* + * We may memcpy more than the original allocation request size, which + * would result in trying to copy trailing bytes that the original + * MemoryContextAllocAligned call marked NOACCESS. So we must mark the + * entire old_size as defined. That's slightly annoying, but probably not + * worth improving. + */ + VALGRIND_MAKE_MEM_DEFINED(pointer, old_size); + memcpy(newptr, pointer, Min(size, old_size)); + pfree(unaligned); return newptr; |