ELF101 a Linux executable walkthrough

Re:ELF101 a Linux executable walkthrough by 1_player on Wednesday November 20, 2013 @06:14AM (#6767382)

Very nice, too bad there are a few typos. For example, the "write" function arguments are not ordered correctly and it's using the wrong line terminator. It should be:

    write(STDOUT, "Hello World!\n", len("Hello World!\n"));

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Re:ELF101 a Linux executable walkthrough by unwind on Wednesday November 20, 2013 @06:44AM (#6767483)

Uh, if that's supposed to be C, then there's no STDOUT and the way to compute the length of a string is with strlen(), not len(). It should be STDOUT_FILENO as pointed out below.

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Re:ELF101 a Linux executable walkthrough by ange4771_ on Wednesday November 20, 2013 @06:24AM (#6767408)

thx, will fix it. any other typo ?

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Re:ELF101 a Linux executable walkthrough by lubomir on Wednesday November 20, 2013 @06:33AM (#6767442)

In code example, the hexdump starts with B9 90 00 00 08, but in the disassembly is listed as 80 00 00 90. I don't think endianness can change 08 to 80.

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Re:ELF101 a Linux executable walkthrough by ange4771_ on Wednesday November 20, 2013 @06:37AM (#6767458)

not even German endianness ? ;)

thanks for pointing this out.

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Re:ELF101 a Linux executable walkthrough by acc00 on Wednesday November 20, 2013 @06:28AM (#6767429)

there is no such predefined thing as STDOUT.

you are probably thinking of STDOUT_FILENO. can you just put "1" there?

also, reordering the "mov"s (so they appear in actual call order: edx, ecx, ebx) will simplify the diagram somewhat.

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