非常奇怪的段错误调用 WinUsb_GetOverlappedResult

2022-01-12 00:00:00 windows gcc segmentation-fault c++ stdcall

我有这个代码:

void GetResult(WINUSB_INTERFACE_HANDLE InterfaceHandle, LPOVERLAPPED lpOverlapped)
{
    DWORD numBytes = 0;
    WinUsb_GetOverlappedResult(
                InterfaceHandle,
                lpOverlapped,
                &numBytes,
                TRUE
                );
    return;

    uint8_t stack[64];
}

WinUsb_GetOverlappedResult 是一个 __stdcall 函数，声明如下:

WinUsb_GetOverlappedResult is a __stdcall function declared as follows:

WINBOOL WINAPI WinUsb_GetOverlappedResult (WINUSB_INTERFACE_HANDLE InterfaceHandle, LPOVERLAPPED lpOverlapped, LPDWORD lpNumberOfBytesTransferred, WINBOOL bWait);

使用 GCC 5.3.0 (MinGW) 在调试模式下编译一切正常.(我无法使用 VC++ 编译，因为我使用的是 GCC 扩展.)

Compiling in debug mode with GCC 5.3.0 (MinGW) it all works fine. (I can't compile with VC++ because I'm using GCC extensions.)

但是如果我把它改成 stack[80] 那么它会出现段错误！！

However if I change it to stack[80] then it segfaults!!

这是每种情况下的反汇编.64(不会崩溃):

Here is the disassembly in each case. 64 (doesn't crash):

Dump of assembler code for function GetResult(void*, _OVERLAPPED*): 88 { 0x00408523 <+0>: push %ebp 0x00408524 <+1>: mov %esp,%ebp 0x00408526 <+3>: sub $0x68,%esp 89 DWORD numBytes = 0; 0x00408529 <+6>: movl $0x0,-0xc(%ebp) 90 WinUsb_GetOverlappedResult( 91 InterfaceHandle, 92 lpOverlapped, 93 &numBytes, 94 TRUE 95 ); => 0x00408530 <+13>: movl $0x1,0xc(%esp) 0x00408538 <+21>: lea -0xc(%ebp),%eax 0x0040853b <+24>: mov %eax,0x8(%esp) 0x0040853f <+28>: mov 0xc(%ebp),%eax 0x00408542 <+31>: mov %eax,0x4(%esp) 0x00408546 <+35>: mov 0x8(%ebp),%eax 0x00408549 <+38>: mov %eax,(%esp) 0x0040854c <+41>: call 0x409d58 <WinUsb_GetOverlappedResult@16> 0x00408551 <+46>: sub $0x10,%esp 96 return; 0x00408554 <+49>: nop 97 98 uint8_t stack[64]; 99 } 0x00408555 <+50>: leave 0x00408556 <+51>: ret

还有 80(确实崩溃):

And 80 (does crash):

Dump of assembler code for function GetResult(void*, _OVERLAPPED*): 88 { 0x00408523 <+0>: push %ebp 0x00408524 <+1>: mov %esp,%ebp 0x00408526 <+3>: sub $0x78,%esp 89 DWORD numBytes = 0; 0x00408529 <+6>: movl $0x0,-0xc(%ebp) 90 WinUsb_GetOverlappedResult( 91 InterfaceHandle, 92 lpOverlapped, 93 &numBytes, 94 TRUE 95 ); => 0x00408530 <+13>: movl $0x1,0xc(%esp) 0x00408538 <+21>: lea -0xc(%ebp),%eax 0x0040853b <+24>: mov %eax,0x8(%esp) 0x0040853f <+28>: mov 0xc(%ebp),%eax 0x00408542 <+31>: mov %eax,0x4(%esp) 0x00408546 <+35>: mov 0x8(%ebp),%eax 0x00408549 <+38>: mov %eax,(%esp) 0x0040854c <+41>: call 0x409d58 <WinUsb_GetOverlappedResult@16> 0x00408551 <+46>: sub $0x10,%esp 96 return; 0x00408554 <+49>: nop 97 98 uint8_t stack[80]; 99 } 0x00408555 <+50>: leave 0x00408556 <+51>: ret

__stdcall 的效果是添加 sub $0x10,%esp 这行我猜是取消 ret $0x10在函数中.

The effect of the __stdcall is to add the line sub $0x10,%esp which I guess is to cancel out ret $0x10 in the function.

无论如何，这些看起来非常相似，我不知道它为什么会崩溃.我什至不能 100% 确定它在哪里崩溃(GDB 相当无用)，但它在 WinUsb 函数调用附近.

In any case these seem very similar and I have no idea why it is crashing. I'm not even 100% sure where it is crashing (GDB is rather unhelpful) but it is somewhere around WinUsb function call.

调试非常困难，因为如果我在设置了任何断点的情况下运行调试器，它就不会崩溃.我怀疑这可能与时间有关-我还可以通过一些额外的 Sleep(100) 来防止崩溃.一旦它似乎在 PerfIncrementULongLongLongCounterValue() 中崩溃，但谁知道...

It's quite hard to debug because if I run the debugger with any breakpoints set, it doesn't crash. I suspect it may be timing related - I can also prevent the crash with a few extra Sleep(100)s. Once it seemed to crash in PerfIncrementULongLongCounterValue() but who knows...

有人知道为什么会发生这种情况吗?

Does anyone have any clue why this might be happening?

编辑

WinUsb_GetOverlappedResult() 只是根据其程序集直接调用 GetOverlappedResult() ，所以我用它替换调用.现在你需要 stack[96] 来导致崩溃，但是当它发生时，它至少告诉我真正的崩溃在哪里(我认为)！

WinUsb_GetOverlappedResult() just calls straight through to GetOverlappedResult() according to its assembly, so I replace the call with that. Now you need stack[96] to cause the crash, but when it does it at least tells me where the real crash is (I think)!

这里是GetOverlappedResult()的反汇编.它在指示的地方崩溃，因为 ebp 为 0.

Here is the disassembly of GetOverlappedResult(). It crashes where indicated because ebp is 0.

0x76feaba0 8b ff mov %edi,%edi 0x76feaba2 <+0x0002> 55 push %ebp 0x76feaba3 <+0x0003> 8b ec mov %esp,%ebp 0x76feaba5 <+0x0005> 83 ec 0c sub $0xc,%esp 0x76feaba8 <+0x0008> a1 94 4b 09 77 mov 0x77094b94,%eax 0x76feabad <+0x000d> 33 c5 xor %ebp,%eax 0x76feabaf <+0x000f> 89 45 fc mov %eax,-0x4(%ebp) 0x76feabb2 <+0x0012> 83 7d 14 00 cmpl $0x0,0x14(%ebp) 0x76feabb6 <+0x0016> 53 push %ebx 0x76feabb7 <+0x0017> 56 push %esi 0x76feabb8 <+0x0018> 57 push %edi 0x76feabb9 <+0x0019> 0f 84 b3 00 00 00 je 0x76feac72 <KERNELBASE!GetOverlappedResult+210> 0x76feabbf <+0x001f> 83 cf ff or $0xffffffff,%edi 0x76feabc2 <+0x0022> 8b 5d 08 mov 0x8(%ebp),%ebx 0x76feabc5 <+0x0025> 83 cb 01 or $0x1,%ebx 0x76feabc8 <+0x0028> 85 ff test %edi,%edi 0x76feabca <+0x002a> 0f 84 a9 00 00 00 je 0x76feac79 <KERNELBASE!GetOverlappedResult+217> 0x76feabd0 <+0x0030> b8 01 00 00 00 mov $0x1,%eax 0x76feabd5 <+0x0035> c7 45 f4 01 00 00 00 movl $0x1,-0xc(%ebp) 0x76feabdc <+0x003c> 89 45 f8 mov %eax,-0x8(%ebp) 0x76feabdf <+0x003f> 84 d8 test %bl,%al 0x76feabe1 <+0x0041> 0f 84 5e f3 03 00 je 0x77029f45 <KERNELBASE!GetCurrentProcess+43221> 0x76feabe7 <+0x0047> 6a 00 push $0x0 0x76feabe9 <+0x0049> 68 dc 10 f2 76 push $0x76f210dc 0x76feabee <+0x004e> 50 push %eax 0x76feabef <+0x004f> 68 ab ab ab ab push $0xabababab 0x76feabf4 <+0x0054> ff 15 68 80 09 77 call *0x77098068 0x76feabfa <+0x005a> 8b f0 mov %eax,%esi 0x76feabfc <+0x005c> 85 f6 test %esi,%esi 0x76feabfe <+0x005e> 74 0e je 0x76feac0e <KERNELBASE!GetOverlappedResult+110> 0x76feac00 <+0x0060> 8d 45 f4 lea -0xc(%ebp),%eax 0x76feac03 <+0x0063> 8b ce mov %esi,%ecx 0x76feac05 <+0x0065> 50 push %eax 0x76feac06 <+0x0066> ff 15 5c 8a 09 77 call *0x77098a5c 0x76feac0c <+0x006c> ff d6 call *%esi 0x76feac0e <+0x006e> 33 c0 xor %eax,%eax 0x76feac10 <+0x0070> 83 e3 fe and $0xfffffffe,%ebx 0x76feac13 <+0x0073> 89 45 f8 mov %eax,-0x8(%ebp) 0x76feac16 <+0x0076> 39 45 f4 cmp %eax,-0xc(%ebp) 0x76feac19 <+0x0079> 0f 85 26 f3 03 00 jne 0x77029f45 <KERNELBASE!GetCurrentProcess+43221> 0x76feac1f <+0x007f> 8b 75 0c mov 0xc(%ebp),%esi 0x76feac22 <+0x0082> 81 3e 03 01 00 00 cmpl $0x103,(%esi) 0x76feac28 <+0x0088> 74 26 je 0x76feac50 <KERNELBASE!GetOverlappedResult+176> Crash: 0x76feac2a <+0x008a> 8b 45 10 mov 0x10(%ebp),%eax 0x76feac2d <+0x008d> 8b 4e 04 mov 0x4(%esi),%ecx 0x76feac30 <+0x0090> 89 08 mov %ecx,(%eax) 0x76feac32 <+0x0092> 8b 0e mov (%esi),%ecx 0x76feac34 <+0x0094> 85 c9 test %ecx,%ecx 0x76feac36 <+0x0096> 78 31 js 0x76feac69 <KERNELBASE!GetOverlappedResult+201> 0x76feac38 <+0x0098> b8 01 00 00 00 mov $0x1,%eax 0x76feac3d <+0x009d> 8b 4d fc mov -0x4(%ebp),%ecx 0x76feac40 <+0x00a0> 5f pop %edi 0x76feac41 <+0x00a1> 5e pop %esi 0x76feac42 <+0x00a2> 33 cd xor %ebp,%ecx 0x76feac44 <+0x00a4> 5b pop %ebx 0x76feac45 <+0x00a5> e8 0b f0 02 00 call 0x77019c55 <PerfIncrementULongLongCounterValue+197> 0x76feac4a <+0x00aa> 8b e5 mov %ebp,%esp 0x76feac4c <+0x00ac> 5d pop %ebp 0x76feac4d <+0x00ad> c2 10 00 ret $0x10 0x76feac50 <+0x00b0> 8b 46 10 mov 0x10(%esi),%eax 0x76feac53 <+0x00b3> 85 c0 test %eax,%eax 0x76feac55 <+0x00b5> 74 46 je 0x76feac9d <KERNELBASE!GetOverlappedResult+253> 0x76feac57 <+0x00b7> 6a 00 push $0x0 0x76feac59 <+0x00b9> 57 push %edi 0x76feac5a <+0x00ba> 50 push %eax 0x76feac5b <+0x00bb> e8 50 01 00 00 call 0x76feadb0 <WaitForSingleObjectEx> 0x76feac60 <+0x00c0> 85 c0 test %eax,%eax 0x76feac62 <+0x00c2> 74 c6 je 0x76feac2a <KERNELBASE!GetOverlappedResult+138> 0x76feac64 <+0x00c4> e9 fb f2 03 00 jmp 0x77029f64 <KERNELBASE!GetCurrentProcess+43252> 0x76feac69 <+0x00c9> e8 d2 f1 ff ff call 0x76fe9e40 <OpenThreadToken+64> 0x76feac6e <+0x00ce> 33 c0 xor %eax,%eax 0x76feac70 <+0x00d0> eb cb jmp 0x76feac3d <KERNELBASE!GetOverlappedResult+157> 0x76feac72 <+0x00d2> 33 ff xor %edi,%edi 0x76feac74 <+0x00d4> e9 49 ff ff ff jmp 0x76feabc2 <KERNELBASE!GetOverlappedResult+34> 0x76feac79 <+0x00d9> 8b 75 0c mov 0xc(%ebp),%esi 0x76feac7c <+0x00dc> 81 3e 03 01 00 00 cmpl $0x103,(%esi) 0x76feac82 <+0x00e2> 74 0a je 0x76feac8e <KERNELBASE!GetOverlappedResult+238> 0x76feac84 <+0x00e4> 33 c9 xor %ecx,%ecx 0x76feac86 <+0x00e6> 8d 45 f8 lea -0x8(%ebp),%eax 0x76feac89 <+0x00e9> f0 09 08 lock or %ecx,(%eax) 0x76feac8c <+0x00ec> eb 9c jmp 0x76feac2a <KERNELBASE!GetOverlappedResult+138> 0x76feac8e <+0x00ee> 68 e4 03 00 00 push $0x3e4 0x76feac93 <+0x00f3> ff 15 c4 80 09 77 call *0x770980c4 0x76feac99 <+0x00f9> 33 c0 xor %eax,%eax 0x76feac9b <+0x00fb> eb a0 jmp 0x76feac3d <KERNELBASE!GetOverlappedResult+157> 0x76feac9d <+0x00fd> 8b c3 mov %ebx,%eax 0x76feac9f <+0x00ff> eb b6 jmp 0x76feac57 <KERNELBASE!GetOverlappedResult+183> 0x76feaca1 <+0x0101> cc int3 0x76feaca2 <+0x0102> cc int3 0x76feaca3 <+0x0103> cc int3 0x76feaca4 <+0x0104> cc int3 0x76feaca5 <+0x0105> cc int3 0x76feaca6 <+0x0106> cc int3 0x76feaca7 <+0x0107> cc int3 0x76feaca8 <+0x0108> cc int3 0x76feaca9 <+0x0109> cc int3 0x76feacaa <+0x010a> cc int3 0x76feacab <+0x010b> cc int3 0x76feacac <+0x010c> cc int3 0x76feacad <+0x010d> cc int3 0x76feacae <+0x010e> cc int3 0x76feacaf <+0x010f> cc int3

推荐答案

我认为我想通了.或许.我改变的是我不再移动我的 OVERLAPPED 结构.我只能假设 WinUsb 保留了一个指向您在开始写入时传递的 OVERLAPPED 的指针.如果它移动了，那么大概事情就会破裂.

Well I think I figured this out. Maybe. The thing I changed is that I don't move my OVERLAPPED structure any more. I can only assume that WinUsb retains a pointer to the OVERLAPPED you pass when you start the write. If it moves then presumably things break.

这在我可以找到的任何地方都没有提到崩溃.

This isn't mentioned anywhere I can find int the documentation for OVERLAPPED but changing my code so that the OVERLAPPED is dynamically allocated once and never moved seems to stop the crashes.

不幸的是，我从未找到调试它的好方法.最好的方法是可逆调试器，但它们似乎不适用于 Windows.

Unfortunately I never found a good way to debug it. The best way would be a reversible debugger but they don't seem to exist for Windows.

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