Fixed bug 1846 - _allmul implementation in SDL_stdlib.c doesn't clean up the stack
authorSam Lantinga <slouken@libsdl.org>
Thu, 16 May 2013 00:43:22 -0700
changeset 71803733e68edbc3
parent 7179 d6acc2d7f760
child 7181 d35a0936c674
Fixed bug 1846 - _allmul implementation in SDL_stdlib.c doesn't clean up the stack

Colin Barrett

I see this manifest itself (VS2012 x86) as:

"Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention."

in the first call to SDL_GetTicks in my application. The disassembly at the problem line is:

hires_now.QuadPart *= 1000;
00AD0792 push 0
00AD0794 push 3E8h
00AD0799 mov eax,dword ptr [ebp-10h]
00AD079C push eax
00AD079D mov ecx,dword ptr [hires_now]
00AD07A0 push ecx
00AD07A1 call _allmul (0AE7D40h)
00AD07A6 mov dword ptr [hires_now],eax
00AD07A9 mov dword ptr [ebp-10h],edx

Apparently _allmul should be popping the stack but isn't (other similar functions in SDL_stdlib.c - _alldiv and whatnot - DO pop the stack).

A 'ret 10h' at the end of _allmul appears to do the trick
src/stdlib/SDL_stdlib.c
     1.1 --- a/src/stdlib/SDL_stdlib.c	Wed May 15 23:18:29 2013 -0700
     1.2 +++ b/src/stdlib/SDL_stdlib.c	Thu May 16 00:43:22 2013 -0700
     1.3 @@ -191,7 +191,7 @@
     1.4          pop         esi
     1.5          pop         edi
     1.6          pop         ebp
     1.7 -        ret
     1.8 +        ret         10h
     1.9      }
    1.10      /* *INDENT-ON* */
    1.11  }