diff options
Diffstat (limited to 'common_modules/module_manager/src/txm_module_manager_object_allocate.c')
| -rw-r--r-- | common_modules/module_manager/src/txm_module_manager_object_allocate.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/common_modules/module_manager/src/txm_module_manager_object_allocate.c b/common_modules/module_manager/src/txm_module_manager_object_allocate.c index 92ae128c..8e452b44 100644 --- a/common_modules/module_manager/src/txm_module_manager_object_allocate.c +++ b/common_modules/module_manager/src/txm_module_manager_object_allocate.c @@ -9,6 +9,8 @@ * SPDX-License-Identifier: MIT **************************************************************************/ +// Portions of this file were generated with AI assistance. + /**************************************************************************/ /**************************************************************************/ @@ -23,6 +25,7 @@ #define TX_SOURCE_CODE #include "txm_module.h" +#include "txm_module_manager_util.h" /**************************************************************************/ /* */ @@ -51,6 +54,11 @@ /* OUTPUT */ /* */ /* status Completion status */ +/* TXM_MODULE_MATH_OVERFLOW is */ +/* returned when object_size is so */ +/* large that adding the manager's */ +/* own object header to it would */ +/* not be representable */ /* */ /* CALLS */ /* */ @@ -67,6 +75,7 @@ UINT _txm_module_manager_object_allocate(VOID **object_ptr_ptr, ULONG object_siz { TXM_MODULE_ALLOCATED_OBJECT *object_ptr; +ULONG allocation_size; UINT return_value; @@ -81,6 +90,18 @@ UINT return_value; /* Initialize the return pointer to NULL. */ *((VOID **) object_ptr_ptr) = TX_NULL; + /* Work out how much memory the pool must supply: the size the caller asked for plus + the private header this function writes in front of it. The size is supplied by + the module, so the addition is checked. An unchecked one wraps for sizes near the + top of a ULONG and asks the pool for fewer bytes than the header alone occupies, + after which the header stores below run past the end of the allocation and into + the neighbouring pool block. Sizes that survive the addition but exceed the pool + are refused by _txe_byte_allocate, which bounds every request by the pool size. + + This is done before the protection mutex is taken so that a refused request leaves + the object pool, the module's allocated object list and its count untouched. */ + TXM_MODULE_MANAGER_UTIL_MATH_ADD_ULONG(object_size, (ULONG) sizeof(TXM_MODULE_ALLOCATED_OBJECT), allocation_size); + /* Get module manager protection mutex. */ _txe_mutex_get(&_txm_module_manager_mutex, TX_WAIT_FOREVER); @@ -90,10 +111,10 @@ UINT return_value; TXM_MODULE_ALLOCATED_OBJECT *next_object, *previous_object; - /* Allocate the object requested by the module - adding an extra ULONG in order to - store the module instance pointer. */ + /* Allocate the object requested by the module, including the header checked above + that holds the owning module instance, the allocation list links and the size. */ return_value = (ULONG) _txe_byte_allocate(&_txm_module_manager_object_pool, (VOID **) &object_ptr, - (ULONG) (object_size + sizeof(TXM_MODULE_ALLOCATED_OBJECT)), TX_NO_WAIT); + allocation_size, TX_NO_WAIT); /* Determine if the request was successful. */ if (return_value == TX_SUCCESS) |