Hotpatching a C Function on x86

Re:Hotpatching a C Function on x86 by etrevino on Friday April 01, 2016 @03:03PM (#11407587)

Now, if we change the program while it is running, is it going to change the program on disk? I.E., once I've hotpatched this thing, can I rely on the patch "sticking" when I shutdown and reload my program? My understanding of this is rudimentary, so I want to make sure that I understand (even though I don't see a use case for me).

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Re:Hotpatching a C Function on x86 by wintermute42 on Friday April 01, 2016 @03:16PM (#11407707)

What, exactly, do you think is going on here? How on earth would the executable on the disk get modified by pointer manipulation? (without the use of mmap, of course)

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Re:Hotpatching a C Function on x86 by etrevino on Friday April 01, 2016 @03:24PM (#11407776)

Well, that's why I was asking, I wanted to understand. And now I do.

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