！heap -x -v和！heap -flt s之间存在矛盾 [英] contradiction between !heap -x -v and !heap -flt s

问题描述

我正在分析一个显示奇怪的转储:!heap -x -v hexadecimal_address和!heap -flt s size_of_block

I'm analyzing a dump which shows something strange: there seem to be a contradiciton between the command !heap -x -v hexadecimal_address and !heap -flt s size_of_block

我正在询问悬空指针. 在此转储中，该悬挂指针恰好是:0x0bdd00c0

I'm inquiring about dangling pointers. In this dump, this dangling pointer happened to be: 0x0bdd00c0

要检索有关堆内存块的信息，请使用!heap -x -v 0bdd00c0返回

To retrieve info about the heap memory block I use !heap -x -v 0bdd00c0 which returns

    Entry     User      Heap      Segment       Size  PrevSize  Unused    Flags
    -----------------------------------------------------------------------------
    0bdd00b8  0bdd00c0  003b0000  0bc00000        98        20         8  busy

在这种情况下，这表明:

Which shows namely that in this case:

• 内存块处于busy模式(大多数情况下，我的其他转储中的内存在这里都是空闲的)
• 内存块大了0x98个字节
• 内存块是在堆003b0000中管理的.

• the memory block is in busy mode (most of the time in my other dumps the memory is free here)
• the memory block is 0x98 bytes big
• the memory block is managed inside the heap 003b0000.

什么让我感到困惑:

当我启动!heap -flt s 98时(只是想观察具有相同大小的其他对象) 我得到的结果不显示我调查的指针0bdd00c0

When I launch !heap -flt s 98 (just wanting to observe other objects that would have the same size) I get this result which doesn't display the pointer 0bdd00c0 of my investigation

      HEAP_ENTRY Size Prev Flags    UserPtr UserSize - state
   _HEAP @ 3b0000
       14b24fa8 0014 0014  [01]   14b24fb0    00098 - (busy)
       0bc645a8 0014 0014  [01]   0bc645b0    00098 - (busy)
       0bc66398 0014 0014  [01]   0bc663a0    00098 - (busy)
       0bcbedf8 0014 0014  [01]   0bcbee00    00098 - (busy)
       0bce2cc8 0014 0014  [01]   0bce2cd0    00098 - (busy)
       0bceff88 0014 0014  [00]   0bceff90    00098 - (free)
       0bdf2f78 0014 0014  [01]   0bdf2f80    00098 - (busy)
       0be28c50 0014 0014  [01]   0be28c58    00098 - (busy)
       0be57470 0014 0014  [00]   0be57478    00098 - (free)
       0beed050 0014 0014  [01]   0beed058    00098 - (busy)
       0bf1aaf0 0014 0014  [00]   0bf1aaf8    00098 - (free)
       0bf214c0 0014 0014  [00]   0bf214c8    00098 - (free)
       0bf99bf0 0014 0014  [00]   0bf99bf8    00098 - (free)

(我只给了您3b0000堆相关的摘录)

所以我得出的结论是似乎存在矛盾.

So I came to the conclusion that there seem to be a contradiction.

我在做/假设有什么问题吗?我该怎么做才能了解问题所在?

Am I doing/assuming something wrong ? What could I do to understand what's wrong ?

推荐答案

您忽略了8个未使用的字节，请尝试

You have overlooked the 8 unused bytes, try

!heap -flt s 90

来自我的测试"编

0:000> !heap -x -v 0x003dc710 
Entry     User      Heap      Segment       Size  PrevSize  Unused    Flags
 -----------------------------------------------------------------------------
 003dc708  003dc710  003d0000  003d0000      1310        40         d  busy 

0:000> ? 1310-d        
Evaluate expression: 4867 = 00001303

0:000> !heap -flt s 1303
_HEAP @ 3d0000
  HEAP_ENTRY Size Prev Flags    UserPtr UserSize - state
    003dc708 0262 0000  [00]   003dc710    01303 - (busy)

此处分配的更多详细信息:

More detail of the allocation here:

0:000> !heap -i 3d0000
Heap context set to the heap 0x003d0000
0:000> !heap -i 003dc708 
Detailed information for block entry 003dc708
Assumed heap       : 0x003d0000 (Use !heap -i NewHeapHandle to change)
Header content     : 0x6334FAFC 0x0D00FD4A (decoded : 0x61010262 0x0D000008)
Owning segment     : 0x003d0000 (offset 0)
Block flags        : 0x1 (busy )
Total block size   : 0x262 units (0x1310 bytes)
Requested size     : 0x1303 bytes (unused 0xd bytes)
Previous block size: 0x8 units (0x40 bytes)
Block CRC          : OK - 0x61  
Previous block     : 0x003dc6c8
Next block         : 0x003dda18

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