93 lines
2.4 KiB
Markdown
93 lines
2.4 KiB
Markdown
# dwarf-synthesis
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A tool for automatic synthesis of DWARF.
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The purpose of this tool is to take any given binary program or library,
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examine its assembly code and, based solely on that, generate the corresponding
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`.eh_frame` DWARF data.
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## Dependencies
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This tool relies on
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* `opam` set up with an OCaml 4.05 switch (see below),
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* [BAP](https://github.com/BinaryAnalysisPlatform/bap) version 1.5 as of today,
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which is available through OPAM;
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* `objcopy`, often packaged as `binutils`
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* `libelf`
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* `libdwarf`
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* `libdwarfw`, packaged as submodule
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### Installing dependencies
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You should be able to easily install `objcopy` (`binutils`), `libelf`,
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`libdwarf` and `opam` via your package manager.
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Once [`opam` is set up](https://opam.ocaml.org/doc/Install.html), you will have
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to use an `OCaml 4.05` opam switch. If you are not familiar with opam, we
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recommand using a fresh switch:
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```bash
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# If you never used opam before on this session:
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opam init
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eval $(opam config env)
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opam switch create dwarf-synthesis ocaml-base-compiler.4.05.0 # With opam 2
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# OR
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opam switch dwarf-synthesis --alias-of 4.05.0 # With opam 1.x
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# Always:
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eval $(opam config env)
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opam install bap
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```
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## Compiling
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Simply run `make` to compile all the necessary tools, including compiling and
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installing the BAP plugin `dwarfsynth`.
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## Running with a wrapper script
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To generate an `.eh_frame` section for some binary `foo.bin` and write the
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output as `foo.eh.bin`, you can run
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```
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./synthesize_dwarf foo.bin foo.eh.bin
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```
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You can also omit the second parameter to simply overwrite `foo.bin`.
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## Running by hand
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If you want, for some reason, to run by hand the multiple components, you can
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follow this procedure (by using more appropriate file names, and, possibly, a
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temporary directory -- see `mktemp -d`).
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### Running the BAP plugin
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`bap prog_to_analyze.bin -p dwarfsynth --dwarfsynth-output tmp.marshal`
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### Running `ml_dwarf_write`
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You can get a help text with `./ml_dwarf_write.bin`. Otherwise, you can run
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```
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./ml_dwarf_write.bin tmp.marshal prog_to_analyze.bin eh_frame_section`
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```
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### Stitching the section into a binary
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```
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objcopy --add-section .eh_frame=eh_frame_section prog_to_analyze.bin prog_to_analyze.eh.bin
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```
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## Commonly used commands
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### List a binary sections
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`objdump -h blah.bin`
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### Strip a binary of its `eh_frame`
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`objcopy --remove-section '.eh_frame' --remove-section '.eh_frame_hdr' blah.bin`
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