diff options
| -rw-r--r-- | common/dlmalloc.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/common/dlmalloc.c b/common/dlmalloc.c index b09f5249a9..adc680e959 100644 --- a/common/dlmalloc.c +++ b/common/dlmalloc.c @@ -1909,6 +1909,7 @@ Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes; * fulfill the user's request. */ if (m == NULL) { + size_t extra, extra2; /* * Use bytes not nb, since mALLOc internally calls request2size too, and * each call increases the size to allocate, to account for the header. @@ -1917,9 +1918,27 @@ Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes; /* Aligned -> return it */ if ((((unsigned long)(m)) % alignment) == 0) return m; - /* Otherwise, fail */ + /* + * Otherwise, try again, requesting enough extra space to be able to + * acquire alignment. + */ fREe(m); - m = NULL; + /* Add in extra bytes to match misalignment of unexpanded allocation */ + extra = alignment - (((unsigned long)(m)) % alignment); + m = (char*)(mALLOc(bytes + extra)); + /* + * m might not be the same as before. Validate that the previous value of + * extra still works for the current value of m. + * If (!m), extra2=alignment so + */ + if (m) { + extra2 = alignment - (((unsigned long)(m)) % alignment); + if (extra2 > extra) { + fREe(m); + m = NULL; + } + } + /* Fall through to original NULL check and chunk splitting logic */ } if (m == NULL) return NULL; /* propagate failure */ |