[M3devel] [M3commit] CVS Update: cm3

Jay jayk123 at hotmail.com
Sun Jan 20 19:13:08 CET 2008


Hey I almost have this figured out.
I compared RTHeapInfo.ms's MM_RTHeapInfo PPC_DARWIN vs. NT386GNU.
They are almost the same.
Ok, anyway, I decided, duh, let's disassembly the garbage data and see if it is code. It is.
That roughly matches the PPC_DARWIN vs. NT386GNU diff where some numbers were off by 4.
Therefore:
 
The module info is this:
0:000> dc 0068113800681138  00681138 00000000 00603de0 00681144
 
when it should be:
 
0:000> dc 0068113800681138  xxxxx 00603de0 00681144
 
Two problems. One clear, one less clear.
 
TYPE (* one of these is generated for each imported interface reference *)  ImportInfo = RECORD    import : ModulePtr;    binder : Binder;    (* returns "import" pointer *)    next   : ImportPtr;  END;
4 bytes of padding are between import and binder.
Making binder be used for next. Making a pointer to code vs. a pointer to data mixed up. That's a big problem.
I understand.
 
What I don't understand is the value of import. I walked the whole list of imports and in every case, the back pointer to the module was actually to the import itself. Huh?
 
Perhaps I went wrong earlier and am off in the weeds..but I don't think so.
I mean, the pointers are to self in any case and that's seldom correct data, unless they are empty circular singly linked lists..
 
I'll dig a bit more..
 
 - Jay
 
 
full debugging session...email is going to remove the newlines and make it unreadable probably..
 
   Module 0x681020 ..\src\runtime\common\RTHeapInfo.m3 Imports 0x6810c0{Import 0x0,    Binder 0x0, Next 0x603d60}   (f88.aec): Access violation - code c0000005 (first chance)   First chance exceptions are reported before any exception handling.   This exception may be expected and handled.   eax=8be58955 ebx=00000001 ecx=611030e8 edx=00008889 esi=611021a0 edi=006147e0   eip=006006a0 esp=0022cb70 ebp=0022cba8 iopl=0         nv up ei ng nz na pe nc   cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010286   *** ERROR: Module load completed but symbols could not be loaded for image00400000         image00400000+0x2006a0:   006006a0 8b00            mov     eax,dword ptr [eax]  ds:0023:8be58955=????????               0:000> dc 0x681020   00681020  00680fe0 00681054 00681154 00000000  ..h.T.h.T.h.....   00681030  00000000 00680f98 00000000 00680fdc  ......h.......h.   00681040  00680fdc 006810c0 00000000 0060053f  ..h...h.....?.`.   00681050  00000003 00000000 6c810e28 72d376bc  ........(..l.v.r   00681060  1e527894 01000201 00000000 00000000  .xR.............   00681070  00000000 00681004 00000000 00000000  ......h.........   00681080  0068100c 00000000 e545939d 00000000  ..h.......E.....   00681090  00000000 00000000 00000000 00681008  ..............h.            0:000> dc 006810c0
   006810c0  00000000 00000000 00603d60 006810cc  ........`=`...h.   006810d0  00000000 005fb070 006810d8 00000000  ....p._...h.....   006810e0  005fb4a0 006810e4 00000000 005f1c00  .._...h......._.   006810f0  006810f0 00000000 005f58d0 006810fc  ..h......X_...h.   00681100  00000000 00606500 00681108 00000000  .....e`...h.....   00681110  006064f0 00681114 00000000 005f8790  .d`...h......._.   00681120  00681120 00000000 00605350 0068112c   .h.....PS`.,.h.   00681130  00000000 00606520 00681138 00000000  .... e`.8.h.....
oops, code not data, let's try the next one
   0:000> dc 00603d60         00603d60  8be58955 d0b80845 c900681a 909090c3  U...E....h......   00603d70  8be58955 90b80845 c900681b e58955c3  U...E....h...U..   00603d80  ec835657 08458b20 8904c083 1bf8a1c2  WV.. .E.........   00603d90  f4050068 8b000000 dc7d8d00 b8fcc689  h.........}.....   00603da0  00000007 a5f3c189 758dd789 07b8fcdc  ...........u....   00603db0  89000000 83a5f3c1 5f5e20c4 9090c3c9  ......... ^_....   00603dc0  8be58955 70b80845 c900681c 909090c3  U...E..p.h......   00603dd0  8be58955 10b80845 c900681d 909090c3  U...E....h......
   0:000> dc 006810cc
   006810cc  006810cc 00000000 005fb070 006810d8  ..h.....p._...h.   006810dc  00000000 005fb4a0 006810e4 00000000  ......_...h.....   006810ec  005f1c00 006810f0 00000000 005f58d0  .._...h......X_.   006810fc  006810fc 00000000 00606500 00681108  ..h......e`...h.   0068110c  00000000 006064f0 00681114 00000000  .....d`...h.....   0068111c  005f8790 00681120 00000000 00605350  .._. .h.....PS`.   0068112c  0068112c 00000000 00606520 00681138  ,.h..... e`.8.h.   0068113c  00000000 00603de0 00681144 00000000  .....=`.D.h.....
   0:000> dc 006810d8
   006810d8  006810d8 00000000 005fb4a0 006810e4  ..h......._...h.   006810e8  00000000 005f1c00 006810f0 00000000  ......_...h.....   006810f8  005f58d0 006810fc 00000000 00606500  .X_...h......e`.   00681108  00681108 00000000 006064f0 00681114  ..h......d`...h.   00681118  00000000 005f8790 00681120 00000000  ......_. .h.....   00681128  00605350 0068112c 00000000 00606520  PS`.,.h..... e`.   00681138  00681138 00000000 00603de0 00681144  8.h......=`.D.h.   00681148  00000000 005dfc00 00000000 00680f00  ......].......h.
oops, this is code not data
0:000> dc 005fb4a0
005fb4a0  8be58955 80b80845 c90067af 909090c3  U...E....g......005fb4b0  8be58955 40b80845 c90067b1 909090c3  U...E.. at .g......005fb4c0  83e58955 45c738ec 000000dc 08458b00  U....8.E......E.005fb4d0  8b04c083 d8458900 83d8458b 1d7f0ff8  ......E..E......005fb4e0  8308458b e8500cec 00011e94 8910c483  .E....P.........005fb4f0  458be045 cc4589e0 0000f9e9 d8458b00  E..E..E.......E.005fb500  500cec83 0000f2e8 10c48300 8be04589  ...P.........E..005fb510  4589e045 d8458bdc 8e0fc085 000000d0  E..E..E.........
let's try the next one
0:000> dc 006810e4
006810e4  006810e4 00000000 005f1c00 006810f0  ..h......._...h.006810f4  00000000 005f58d0 006810fc 00000000  .....X_...h.....00681104  00606500 00681108 00000000 006064f0  .e`...h......d`.00681114  00681114 00000000 005f8790 00681120  ..h......._. .h.00681124  00000000 00605350 0068112c 00000000  ....PS`.,.h.....00681134  00606520 00681138 00000000 00603de0   e`.8.h......=`.00681144  00681144 00000000 005dfc00 00000000  D.h.......].....00681154  00680f00 00000000 6c810e28 00000002  ..h.....(..l....
 
0:000> dc 006810e4
006810e4  006810e4 00000000 005f1c00 006810f0  ..h......._...h.006810f4  00000000 005f58d0 006810fc 00000000  .....X_...h.....00681104  00606500 00681108 00000000 006064f0  .e`...h......d`.00681114  00681114 00000000 005f8790 00681120  ..h......._. .h.00681124  00000000 00605350 0068112c 00000000  ....PS`.,.h.....00681134  00606520 00681138 00000000 00603de0   e`.8.h......=`.00681144  00681144 00000000 005dfc00 00000000  D.h.......].....00681154  00680f00 00000000 6c810e28 00000002  ..h.....(..l....
 
show it to be code btw (I did this earlier, not sure what happened in the log;I cannot represent byte patterns as x86 code by sight, but the disassembly is spot on)
0:000> u 005f1c00
image00400000+0x1f1c00:005f1c00 55              push    ebp005f1c01 89e5            mov     ebp,esp005f1c03 8b4508          mov     eax,dword ptr [ebp+8]005f1c06 b8a0906700      mov     eax,offset image00400000+0x2790a0 (006790a0)005f1c0b c9              leave005f1c0c c3              ret005f1c0d 90              nop005f1c0e 90              nop
ok, so again let's try the next
0:000> dc 006810f0
006810f0  006810f0 00000000 005f58d0 006810fc  ..h......X_...h.00681100  00000000 00606500 00681108 00000000  .....e`...h.....00681110  006064f0 00681114 00000000 005f8790  .d`...h......._.00681120  00681120 00000000 00605350 0068112c   .h.....PS`.,.h.00681130  00000000 00606520 00681138 00000000  .... e`.8.h.....00681140  00603de0 00681144 00000000 005dfc00  .=`.D.h.......].00681150  00000000 00680f00 00000000 6c810e28  ......h.....(..l00681160  00000002 00000000 00000000 00000000  ................
0:000> dc 006810fc
006810fc  006810fc 00000000 00606500 00681108  ..h......e`...h.0068110c  00000000 006064f0 00681114 00000000  .....d`...h.....0068111c  005f8790 00681120 00000000 00605350  .._. .h.....PS`.0068112c  0068112c 00000000 00606520 00681138  ,.h..... e`.8.h.0068113c  00000000 00603de0 00681144 00000000  .....=`.D.h.....0068114c  005dfc00 00000000 00680f00 00000000  ..].......h.....0068115c  6c810e28 00000002 00000000 00000000  (..l............0068116c  00000000 79545452 52536570 33495f43  ....RTTypeSRC_I3
0:000> dc 00681108
00681108  00681108 00000000 006064f0 00681114  ..h......d`...h.00681118  00000000 005f8790 00681120 00000000  ......_. .h.....00681128  00605350 0068112c 00000000 00606520  PS`.,.h..... e`.00681138  00681138 00000000 00603de0 00681144  8.h......=`.D.h.00681148  00000000 005dfc00 00000000 00680f00  ......].......h.00681158  00000000 6c810e28 00000002 00000000  ....(..l........00681168  00000000 00000000 79545452 52536570  ........RTTypeSR00681178  33495f43 00000000 00600750 00681170  C_I3....P.`.p.h.
it just keeps going, a pretty good linked listEXCEPT for the padding and the first pointer always looks wrong
0:000> dc 00681114
00681114  00681114 00000000 005f8790 00681120  ..h......._. .h.00681124  00000000 00605350 0068112c 00000000  ....PS`.,.h.....00681134  00606520 00681138 00000000 00603de0   e`.8.h......=`.00681144  00681144 00000000 005dfc00 00000000  D.h.......].....00681154  00680f00 00000000 6c810e28 00000002  ..h.....(..l....00681164  00000000 00000000 00000000 79545452  ............RTTy00681174  52536570 33495f43 00000000 00600750  peSRC_I3....P.`.00681184  00681170 00000000 735c2e2e 725c6372  p.h.......\src\r
0:000> dc 00681120
00681120  00681120 00000000 00605350 0068112c   .h.....PS`.,.h.00681130  00000000 00606520 00681138 00000000  .... e`.8.h.....00681140  00603de0 00681144 00000000 005dfc00  .=`.D.h.......].00681150  00000000 00680f00 00000000 6c810e28  ......h.....(..l00681160  00000002 00000000 00000000 00000000  ................00681170  79545452 52536570 33495f43 00000000  RTTypeSRC_I3....00681180  00600750 00681170 00000000 735c2e2e  P.`.p.h.......\s00681190  725c6372 69746e75 635c656d 6f6d6d6f  rc\runtime\commo
0:000> dc 0068112c
0068112c  0068112c 00000000 00606520 00681138  ,.h..... e`.8.h.0068113c  00000000 00603de0 00681144 00000000  .....=`.D.h.....0068114c  005dfc00 00000000 00680f00 00000000  ..].......h.....0068115c  6c810e28 00000002 00000000 00000000  (..l............0068116c  00000000 79545452 52536570 33495f43  ....RTTypeSRC_I30068117c  00000000 00600750 00681170 00000000  ....P.`.p.h.....0068118c  735c2e2e 725c6372 69746e75 635c656d  ..\src\runtime\c0068119c  6f6d6d6f 54525c6e 65707954 2e435253  ommon\RTTypeSRC.
0:000> dc 00681138
00681138  00681138 00000000 00603de0 00681144  8.h......=`.D.h.00681148  00000000 005dfc00 00000000 00680f00  ......].......h.00681158  00000000 6c810e28 00000002 00000000  ....(..l........00681168  00000000 00000000 79545452 52536570  ........RTTypeSR00681178  33495f43 00000000 00600750 00681170  C_I3....P.`.p.h.00681188  00000000 735c2e2e 725c6372 69746e75  ......\src\runti00681198  635c656d 6f6d6d6f 54525c6e 65707954  me\common\RTType006811a8  2e435253 00003369 0068118c 00000000  SRC.i3....h.....
   0:000> dc 00681144
   00681144  00681144 00000000 005dfc00 00000000  D.h.......].....   00681154  00680f00 00000000 6c810e28 00000002  ..h.....(..l....   00681164  00000000 00000000 00000000 79545452  ............RTTy   00681174  52536570 33495f43 00000000 00600750  peSRC_I3....P.`.   00681184  00681170 00000000 735c2e2e 725c6372  p.h.......\src\r   00681194  69746e75 635c656d 6f6d6d6f 54525c6e  untime\common\RT   006811a4  65707954 2e435253 00003369 0068118c  TypeSRC.i3....h.   006811b4  00000000 00000000 00000000 00000000  ................
   another confirmation of a code pointer
   0:000> u 005dfc00
   image00400000+0x1dfc00:   005dfc00 55              push    ebp   005dfc01 89e5            mov     ebp,esp   005dfc03 8b4508          mov     eax,dword ptr [ebp+8]   005dfc06 b800516700      mov     eax,offset image00400000+0x275100 (00675100)   005dfc0b c9              leave   005dfc0c c3              ret   005dfc0d 90              nop   005dfc0e 90              nop
   0:000>
   This is the nice thing about command line debuggers, a textual log.
 
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