Procedure __security_check_cookie

Code (Delphi)

procedure __security_check_cookie(

var ASecurityCookie: Pointer;

const ALocation: PChar = nil

);

Tip

EurekaLog's crash report for stack buffer overflow may not display full call stack - that is because stack corruption will damage stack frames and return addresses, so damaged part of the stack will be skipped. There may be no call stack at all in some (rare) cases. However, there always will be "error" entry on the stack - e.g. the one corresponding to the routine in which the corruption was detected.

Note

If current routine calls other routines - these routines may also corrupt the stack. If corruption happens inside a sub-routine - then it may happen that the execution flow will be unable to return to the current routine. This means that __security_check_cookie (in the current routine) will not be executed, thus it will be unable to detect stack's corruption. For this reason one should place __initialize_security_cookie/__security_check_cookie in all available routines.

Code (Delphi)

procedure DoSomething;

var

 Cookie: Pointer; // MUST be the first local variable

 // ... other local variables

begin

 __initialize_security_cookie(Cookie);

 // ... you normal code for DoSomething goes here

 __security_check_cookie(Cookie); // will throw an error if stack corruption is detected

 // or:

 // __security_check_cookie(Cookie, 'Unit1.DoSomething');

 // or:

 // __security_check_cookie(Cookie, PChar(__LOCATION__)); // uses EDebugInfo, not recommended

end;