lib: mempool - Centralize p_{m,re}alloc() size checks

Instead of each mempool implementation having to check the allocation sizes
for sanity, we can check that the sizes are within the required bounds in
p_malloc() and p_realloc().

Since p_malloc() and p_realloc() are static inlines, some consumers will see
a little bit of growth in binary size, but others will be able to optimize
the check away at compile time.

src/lib/mempool-allocfree.c

@@ -255,9 +255,6 @@ static void *pool_allocfree_malloc(pool_t pool, size_t size)
 	struct allocfree_pool *apool =
 		container_of(pool, struct allocfree_pool, pool);
 
-	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", size);
-
 	struct pool_block *block = calloc(1, SIZEOF_POOLBLOCK + size);
 	if (block == NULL)
 		i_fatal_status(FATAL_OUTOFMEM, "calloc(1, %"PRIuSIZE_T"): Out of memory",
@@ -285,9 +282,6 @@ static void *pool_allocfree_realloc(pool_t pool, void *mem,
 		container_of(pool, struct allocfree_pool, pool);
 	unsigned char *new_mem;
 
-	if (unlikely(new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", new_size);
-
 	if (mem == NULL)
 		return pool_allocfree_malloc(pool, new_size);
 

src/lib/mempool-alloconly.c

@@ -384,9 +384,6 @@ static void *pool_alloconly_malloc(pool_t pool, size_t size)
 	void *mem;
 	size_t alloc_size;
 
-	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", size);
-
 #ifndef DEBUG
 	alloc_size = MEM_ALIGN(size);
 #else
@@ -454,9 +451,6 @@ static void *pool_alloconly_realloc(pool_t pool, void *mem,
 		container_of(pool, struct alloconly_pool, pool);
 	unsigned char *new_mem;
 
-	if (unlikely(new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", new_size);
-
 	if (mem == NULL)
 		return pool_alloconly_malloc(pool, new_size);
 

src/lib/mempool-datastack.c

@@ -140,9 +140,6 @@ static void *pool_data_stack_malloc(pool_t pool ATTR_UNUSED, size_t size)
 	struct datastack_pool *dpool =
 		container_of(pool, struct datastack_pool, pool);
 
-	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", size);
-
 	if (unlikely(dpool->data_stack_frame != data_stack_frame_id))
 		i_panic("pool_data_stack_malloc(): stack frame changed");
 
@@ -166,9 +163,6 @@ static void *pool_data_stack_realloc(pool_t pool, void *mem,
 	void *new_mem;
 
 	/* @UNSAFE */
-	if (unlikely(new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", new_size);
-
 	if (unlikely(dpool->data_stack_frame != data_stack_frame_id))
 		i_panic("pool_data_stack_realloc(): stack frame changed");
 

src/lib/mempool-system.c

@@ -102,9 +102,6 @@ static void *pool_system_malloc(pool_t pool ATTR_UNUSED, size_t size)
 	int old_errno = errno;
 #endif
 
-	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", size);
-
 	mem = calloc(size, 1);
 	if (unlikely(mem == NULL)) {
 		i_fatal_status(FATAL_OUTOFMEM, "pool_system_malloc(%"PRIuSIZE_T
@@ -135,9 +132,6 @@ void pool_system_free(pool_t pool ATTR_UNUSED, void *mem ATTR_UNUSED)
 static void *pool_system_realloc(pool_t pool ATTR_UNUSED, void *mem,
 				 size_t old_size, size_t new_size)
 {
-	if (unlikely(new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", new_size);
-
 	if (mem == NULL) {
 		i_assert(old_size == 0);
 		return pool_system_malloc(pool, new_size);

src/lib/mempool-unsafe-datastack.c

@@ -96,9 +96,6 @@ static void pool_unsafe_data_stack_unref(pool_t *pool ATTR_UNUSED)
 static void *pool_unsafe_data_stack_malloc(pool_t pool ATTR_UNUSED,
 					   size_t size)
 {
-	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", size);
-
 	return t_malloc0(size);
 }
 
@@ -114,9 +111,6 @@ static void *pool_unsafe_data_stack_realloc(pool_t pool ATTR_UNUSED,
 	void *new_mem;
 
 	/* @UNSAFE */
-	if (new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE)
-		i_panic("Trying to allocate %"PRIuSIZE_T" bytes", new_size);
-
 	if (mem == NULL)
 		return pool_unsafe_data_stack_malloc(pool, new_size);
 

src/lib/mempool.h

@@ -101,12 +101,18 @@ size_t pool_get_exp_grown_size(pool_t pool, size_t old_size, size_t min_size);
 static inline void * ATTR_MALLOC ATTR_RETURNS_NONNULL
 p_malloc(pool_t pool, size_t size)
 {
+	if (unlikely(size == 0 || size > POOL_MAX_ALLOC_SIZE))
+		i_panic("Trying to allocate %" PRIuSIZE_T " bytes", size);
+
 	return pool->v->malloc(pool, size);
 }
 
 static inline void * ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
 p_realloc(pool_t pool, void *mem, size_t old_size, size_t new_size)
 {
+	if (unlikely(new_size == 0 || new_size > POOL_MAX_ALLOC_SIZE))
+		i_panic("Trying to allocate %" PRIuSIZE_T " bytes", new_size);
+
 	return pool->v->realloc(pool, mem, old_size, new_size);
 }