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Re: Custom malloc/mmap for x86_64
Thank you guys for your quick replies. I have a separate library already
working independently that supports my work. I was asked to migrate
it to glibc to provide an actual implementation and deploy it on a
So to answer your questions: my_malloc and malloc, as well as
my_mmap and mmap all have to be supported and may be called
at any time. Whenever free() is called, it works perfectly since both
malloc and my_malloc operate over the same data structures,
so I do not have to worry about keeping track of space that way.
Moreover, malloc and my_malloc can grow the same
heap/virtual address space for the given process.
So, basically, we just need to overload the above methods. I do not want
to overwrite mmap nor malloc. I know how to do that via the -wrap flag
as you guys mentioned. I also know about LD_PRELOAD variable.
But, back to my old question. Out of curiosity because I like to
know how things really work. How does glibc exaclty generate
wrappers for mmap, munmap, et al.?
I know the make-syscals.sh script creates syscall wrappers for
the methods specified in syscalls.list. But when I looked in there
I did not see mmap, munmap, sbrk, etc.
Thank you all!