diff options
Diffstat (limited to 'Objects/obmalloc.c')
| -rw-r--r-- | Objects/obmalloc.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index 8e25229e09..f1462225a0 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -1780,7 +1780,7 @@ static void * _PyMem_DebugRealloc(void *ctx, void *p, size_t nbytes) { debug_alloc_api_t *api = (debug_alloc_api_t *)ctx; - uchar *q = (uchar *)p; + uchar *q = (uchar *)p, *oldq; uchar *tail; size_t total; /* nbytes + 4*SST */ size_t original_nbytes; @@ -1797,24 +1797,26 @@ _PyMem_DebugRealloc(void *ctx, void *p, size_t nbytes) /* overflow: can't represent total as a size_t */ return NULL; - if (nbytes < original_nbytes) { - /* shrinking: mark old extra memory dead */ - memset(q + nbytes, DEADBYTE, original_nbytes - nbytes + 2*SST); - } - /* Resize and add decorations. We may get a new pointer here, in which * case we didn't get the chance to mark the old memory with DEADBYTE, * but we live with that. */ + oldq = q; q = (uchar *)api->alloc.realloc(api->alloc.ctx, q - 2*SST, total); if (q == NULL) return NULL; + if (q == oldq && nbytes < original_nbytes) { + /* shrinking: mark old extra memory dead */ + memset(q + nbytes, DEADBYTE, original_nbytes - nbytes); + } + write_size_t(q, nbytes); assert(q[SST] == (uchar)api->api_id); for (i = 1; i < SST; ++i) assert(q[SST + i] == FORBIDDENBYTE); q += 2*SST; + tail = q + nbytes; memset(tail, FORBIDDENBYTE, SST); write_size_t(tail + SST, serialno); |