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caoyunbin001



Joined: 21 Jan 2012
Posts: 20
caoyunbin001
when assembled with 'relc' fixups,
this dll crashes on LoadLibraryW.

when removed 'relc' fixups,
this dll cannot be loaded to other address but have to be loaded to its IMAGEBASE.

how to fix this?
did some homework:
not the empty section bug, the size of section 'relc' is not zero.

any help is appreciated.


Description:
Download
Filename: build.asm
Filesize: 538 Bytes
Downloaded: 86 Time(s)

Description:
Download
Filename: cxrt4win.asm
Filesize: 6.2 KB
Downloaded: 91 Time(s)

Post 12 Apr 2012, 15:39
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
At DllMain you have " mov ebx,GenerateIncFile", what is this for? It doesn't look like you can take any benefit out of it and at the same time you are violating the stdcall convention so you may be causing the caller of DllMain to crash.

[edit]I get no crash here, and I must say I'm a bit surprised considering the code hits an int3. I have Windows 7 64-bit Home Premium[/edit]
Post 12 Apr 2012, 16:54
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caoyunbin001



Joined: 21 Jan 2012
Posts: 20
caoyunbin001
LocoDelAssembly wrote:
At DllMain you have " mov ebx,GenerateIncFile", what is this for? It doesn't look like you can take any benefit out of it and at the same time you are violating the stdcall convention so you may be causing the caller of DllMain to crash.

[edit]I get no crash here, and I must say I'm a bit surprised considering the code hits an int3. I have Windows 7 64-bit Home Premium[/edit]


at first, i tried to export the address of GenerateIncFile out of the DllMain,
but it doesn't work,you can delete that line.

see the screenshot.


Description:
Filesize: 36.23 KB
Viewed: 975 Time(s)

FASM_DLL_CRASH_ON_SEC_FIXUPS.png


Post 13 Apr 2012, 06:05
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
Does the example that comes with fasm work? I don't know what could be the source of complain.

Try using canonical names for the sections to see if there is any improvement (i.e. '.idata' for imports, '.reloc' for fixups, etc.).
Post 13 Apr 2012, 15:55
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