mmap /proc/<pid>/mem ... alternatives?

[Zinx Verituse <zinx@epicsol.org>]

I have a black-box process (of which I can disassemble enough to
insert debugging traps).  I need to read a large number of sparse
structures that are a few bytes to a few hundred kbyte each.  In
Linux 2.2, I was simply mmap()ing the process's memory, but that
feature seems removed in Linux 2.4, so.. I need alternatives..

Here's a list of things I'm considering:

	provide mmap() patch for /proc/<pid>/mem
		Definitely out of my league :)

	mmap() of /dev/mem
		needs root (I can live with that)

		need to know where the process's memory is --
		  I don't know how to determine this.

	shared memory
		need to bootstrap some code at the beginning (doable)

		I don't know how to re-map the data, bss, and stack to
		  shared memory properly.

	use read/write on /proc/<pid>/mem
		write() doesn't work (doesn't write to the process).

		complicates the code in my program quite a bit.

	hybrid read, ptrace(PTRACE_POKEDATA, ...)
		works, but I would like to avoid all the extra copies,
		  and this complicates the code quite a bit.

	downgrade to 2.2
		Only as an absolute last resort, if nothing else works.

-- 
Zinx Verituse