System and Method for Auditing Memory

Abstract

According to one embodiment of the invention, a method of auditing memory in a system comprises receiving a request for memory from an application and populating a memory tag with a stack depth component and a traceback stack component. The traceback stack component contains a pointer to a traceback stack. The stack depth component defines a size of the traceback stack. The traceback stack contains information from a program stack associated with the application. The embodiment may further comprise determining if a memory pool has enough free memory to satisfy the request and allocating, from the memory pool, a memory allocation unit if the memory pool has enough free memory to satisfy the request. The memory allocation unit may include a data area and a footer. The data area defines an area to which the application may write data and the footer bounds the data area with a special code.

1 . A method of auditing memory in a system, the method comprising:
 receiving a memory request from an application;   populating a memory tag having a stack depth component and a traceback stack component, the traceback stack component containing a pointer to a traceback stack, the stack depth component defining a size of the traceback stack, and the traceback stack containing information from a program stack associated with the applications   determining if a memory pool has enough free memory to satisfy the request for memory; and   allocating, from a memory pool, a memory allocation unit with a data area and a footer, the data area defining an area to which the application may write data, and the footer bounding the data area with a special code.   
     
     
         2 . The method of  claim 1 , wherein the memory request is a request for memory and
 wherein the allocating, from a memory pool, a memory allocation unit with a data area and a footer further comprises allocating, from the memory pool, the memory allocation unit if the memory pool has enough free memory to satisfy the request for memory.   
     
     
         3 . The method of  claim 2 , further comprising:
 receiving a request to return the memory allocation unit;   determining whether the header of the memory allocation unit is valid;   determining whether the special code in the footer of the memory allocation unit has changed; and   returning the memory allocation unit back to the memory pool if the memory allocation unit header is valid and the special code in the footer has not changed.   
     
     
         4 . The method of  claim 2 , wherein the memory tag includes an activity type component defining a type of activity involved in populating the memory tag, further comprising:
 receiving a request to return the memory allocation unit;   determining whether the header of the memory allocation unit is valid; and   populating the activity type component with a deallocation failure flag upon determining that the memory allocation unit header is invalid.   
     
     
         5 . The method of  claim 2 , wherein the memory tag includes an activity type component defining a type of activity involved in populating the memory tag, further comprising:
 receiving a request to return the memory allocation unit;   determining whether the header of the memory allocation unit is valid;   determining whether the special code in the footer of the memory allocation unit has changed; and   populating the activity type component with an overrun flag upon determining that the memory allocation unit header is valid and the special code in the footer has changed.   
     
     
         6 . The method of  claim 1 , further comprising:
 storing the memory tag in a memory tag list.   
     
     
         7 . The method of  claim 6 , further comprising:
 receiving a request to return the memory allocation unit;   determining whether the header of the memory allocation unit is valid;   determining whether the special code in the footer of the memory allocation unit has changed;   returning the memory allocation unit back to the memory pool if the memory allocation unit header is valid and the special code in the footer has not changed; and   removing the memory tag from the memory tag list after returning the memory allocation unit back to the memory pool.   
     
     
         8 . (canceled) 
     
     
         9 . The method of  claim 1 , wherein the memory tag includes an activity type component defining a type of activity involved in populating the memory tag. 
     
     
         10 . The method of  claim 9 , wherein the memory request is a request for memory, further comprising:
 populating the activity type component with an allocation error flag if the memory pool does not have enough memory to satisfy the request for memory.   
     
     
         11 . The method of  claim 9 ], wherein the memory request is a request to return a memory allocation unit from an application, further comprising:
 determining whether the header of the memory allocation unit is valid;   determining whether the special code in the footer of the memory allocation unit has changed; and   populating the activity type component with an overrun flag upon determining that the memory allocation unit header is valid and the special code in the footer has changed.   
     
     
         12 . The method of  claim 1 , wherein the memory request is a request for memory, further comprising:
 reading the program stack associated with the application; and   populating the traceback stack with information from the program stack.   
     
     
         13 . The method of  claim 11 , further comprising:
 storing both the traceback stack and the memory tag in a memory tag list.   
     
     
         14 . A method of auditing memory in a system, the method comprising:
 receiving a request for memory from an application; and   allocating, from a memory pool, a memory allocation unit with a data area and a footer, the data area defining an area to which the application may write data, and the footer bounding the data area with a special code; and   populating a memory tag having a stack depth component and a traceback stack component, the traceback stack component containing a pointer to a traceback stack, the stack depth component defining a size of the traceback stack, and the traceback stack containing information from a program stack associated with the application.   
     
     
         15 . The method of  claim 14 , further comprising:
 receiving a request to return the memory allocation unit;   determining whether the header of the memory allocation unit is valid;   determining whether the special code in the footer of the memory allocation unit has changed; and   returning the memory allocation unit back to the memory pool if the memory allocation unit header is valid and the special code in the footer has not changed.   
     
     
         16 . The method of  claim 15 , wherein the memory allocation unit further includes a header, further comprising:
 validating the header prior to determining whether the footer of the memory allocation unit has changed.   
     
     
         17 . The method of  claim 14 , the memory tag further comprising:
 an activity type component, and a task identification component, the activity type component defining a type of activity involved in populating the memory tag, and the task identification component identifying a task in the application associated with the request for memory.   
     
     
         18 . A memory tag for auditing memory comprising:
 a traceback stack component containing a pointer to a traceback stack, the traceback stack containing information from a program stack;   a stack depth component, the stack depth component defining a size of the traceback stack, and   an activity type component, the activity type component defining a type of activity involved in populating the memory tag, the activity type component storing an allocation flag upon successful allocation of memory.   
     
     
         19 . The memory tag of  claim 18 , further comprising:
 a previous memory tag component, the previous memory tag component pointing towards a previous memory tag stored on a memory tag list; and   a next memory tag component, the next memory tag component pointing towards a next memory tag stored on a memory list.   
     
     
         20 . The memory tag of  claim 18 , wherein the memory tag is associated with an application, further comprising:
 a task identification component identifying a task in the application associated with populating the memory tag.   
     
     
         21 . The memory tag of  claim 18 , wherein the activity type component further stores one of the following: an allocation error flag, an overrun flag, and a deallocation failure flag.