Eric Pouech : dbghelp: Realloc array of buckets inside struct vector.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 363f1f49a8eb3072455358e10dbf040e21e806b1
URL:    https://gitlab.winehq.org/wine/wine/-/commit/363f1f49a8eb3072455358e10dbf040...

Author: Eric Pouech <eric.pouech(a)gmail.com>
Date:   Fri Oct 21 09:58:48 2022 +0200

dbghelp: Realloc array of buckets inside struct vector.

Instead of silently leaking no longer used chunks.
Be more robust to OOM conditions.
Introducing pool_realloc().

Signed-off-by: Eric Pouech <eric.pouech(a)gmail.com>

---

 dlls/dbghelp/dbghelp_private.h |  1 +
 dlls/dbghelp/storage.c         | 28 +++++++++++++---------------
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/dlls/dbghelp/dbghelp_private.h b/dlls/dbghelp/dbghelp_private.h
index ceb92aabc4f..daf15732877 100644
--- a/dlls/dbghelp/dbghelp_private.h
+++ b/dlls/dbghelp/dbghelp_private.h
@@ -42,6 +42,7 @@ struct pool /* poor's man */
 void     pool_init(struct pool* a, size_t arena_size) DECLSPEC_HIDDEN;
 void     pool_destroy(struct pool* a) DECLSPEC_HIDDEN;
 void*    pool_alloc(struct pool* a, size_t len) DECLSPEC_HIDDEN;
+void*    pool_realloc(struct pool* a, void* ptr, size_t len) DECLSPEC_HIDDEN;
 char*    pool_strdup(struct pool* a, const char* str) DECLSPEC_HIDDEN;
 
 struct vector
diff --git a/dlls/dbghelp/storage.c b/dlls/dbghelp/storage.c
index 735fb3bce7e..daed3aa8d99 100644
--- a/dlls/dbghelp/storage.c
+++ b/dlls/dbghelp/storage.c
@@ -43,6 +43,11 @@ void* pool_alloc(struct pool* pool, size_t len)
     return HeapAlloc(pool->heap, 0, len);
 }
 
+void* pool_realloc(struct pool* pool, void* ptr, size_t len)
+{
+    return ptr ? HeapReAlloc(pool->heap, 0, ptr, len) : pool_alloc(pool, len);
+}
+
 char* pool_strdup(struct pool* pool, const char* str)
 {
     char* ret;
@@ -90,32 +95,25 @@ void* vector_at(const struct vector* v, unsigned pos)
 
 void* vector_add(struct vector* v, struct pool* pool)
 {
-    unsigned    ncurr = v->num_elts++;
-
-    /* check that we don't wrap around */
-    assert(v->num_elts > ncurr);
-    if (ncurr == (v->num_buckets << v->shift))
+    if (v->num_elts == (v->num_buckets << v->shift))
     {
-        if(v->num_buckets == v->buckets_allocated)
+        if (v->num_buckets == v->buckets_allocated)
         {
             /* Double the bucket cache, so it scales well with big vectors.*/
-            unsigned    new_reserved;
+            unsigned    new_reserved = v->buckets_allocated ? v->buckets_allocated * 2 : 1;
             void*       new;
 
-            new_reserved = 2*v->buckets_allocated;
-            if(new_reserved == 0) new_reserved = 1;
-
-            /* Don't even try to resize memory.
-               Pool datastructure is very inefficient with reallocs. */
-            new = pool_alloc(pool, new_reserved * sizeof(void*));
-            memcpy(new, v->buckets, v->buckets_allocated * sizeof(void*));
+            new = pool_realloc(pool, v->buckets, new_reserved * sizeof(void*));
+            if (!new) return NULL;
             v->buckets = new;
             v->buckets_allocated = new_reserved;
         }
         v->buckets[v->num_buckets] = pool_alloc(pool, v->elt_size << v->shift);
+        if (!v->buckets[v->num_buckets]) return NULL;
+        v->num_elts++;
         return v->buckets[v->num_buckets++];
     }
-    return vector_at(v, ncurr);
+    return vector_at(v, v->num_elts++);
 }
 
 /* We construct the sparse array as two vectors (of equal size)