Ubuntu Manpage: abidw - serialize the ABI of an ELF file

NAME

       abidw - serialize the ABI of an ELF file

       abidw reads a shared library in ELF format and emits an XML representation of its ABI to standard output.
       The  emitted  representation  includes  all  the  globally  defined functions and variables, along with a
       complete representation of their types.  It also includes a representation of the  globally  defined  ELF
       symbols of the file.  The input shared library must contain associated debug information in DWARF format.

       When  given  the  --linux-tree  option,  this  program  can  also handle a Linux kernel tree.  That is, a
       directory tree that contains both the vmlinux binary and Linux kernel modules.  It analyses  those  Linux
       kernel  binaries  and  emits an XML representation of the interface between the kernel and its module, to
       standard output.  In this case, we don’t call it an ABI,  but  a  KMI  (Kernel  Module  Interface).   The
       emitted  KMI  includes  all  the  globally  defined  functions  and  variables,  along  with  a  complete
       representation of their types.  The input binaries must contain associated  debug  information  in  DWARF
       format.

INVOCATION

          abidw [options] [<path-to-elf-file>]

OPTIONS

• --help | -h

Display a short help about the command and exit.

• –version | -v

Display the version of the program and exit.

• --debug-info-dir | -d <dir-path>

In cases where the debug info for path-to-elf-file is in a separate file that is located in a
non-standard place, this tells abidw where to look for that debug info file.

Note that dir-path must point to the root directory under which the debug information is arranged in
a tree-like manner. Under Red Hat based systems, that directory is usually <root>/usr/lib/debug.

Note that this option is not mandatory for split debug information installed by your system’s
package manager because then abidw knows where to find it.

• --out-file <file-path>

This option instructs abidw to emit the XML representation of path-to-elf-file into the file
file-path, rather than emitting it to its standard output.

• --noout

This option instructs abidw to not emit the XML representation of the ABI. So it only reads the ELF
and debug information, builds the internal representation of the ABI and exits. This option is
usually useful for debugging purposes.

• --no-corpus-path

Do not emit the path attribute for the ABI corpus.

• --suppressions | suppr <path-to-suppression-specifications-file>

Use a suppression specification file located at path-to-suppression-specifications-file. Note that
this option can appear multiple times on the command line. In that case, all of the provided
suppression specification files are taken into account. ABI artifacts matched by the suppression
specifications are suppressed from the output of this tool.

• --kmi-whitelist | -kaw <path-to-whitelist>

When analyzing a Linux kernel binary, this option points to the white list of names of ELF symbols
of functions and variables which ABI must be written out. That white list is called a ” Kernel
Module Interface white list”. This is because for the Kernel, we don’t talk about the ABI; we
rather talk about the interface between the Kernel and its module. Hence the term KMI rather than
ABI

Any other function or variable which ELF symbol are not present in that white list will not be
considered by the KMI writing process.

If this option is not provided – thus if no white list is provided – then the entire KMI, that is,
all publicly defined and exported functions and global variables by the Linux Kernel binaries is
emitted.

• --linux-tree | --lt

Make abidw to consider the input path as a path to a directory containing the vmlinux binary as
several kernel modules binaries. In that case, this program emits the representation of the Kernel
Module Interface (KMI) on the standard output.

Below is an example of usage of abidw on a Linux Kernel tree.

First, checkout a Linux kernel source tree and build it. Then install the kernel modules in a
directory somewhere. Copy the vmlinux binary into that directory too. And then serialize the KMI
of that kernel to disk, using abidw:

$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
$ cd linux && git checkout v4.5
$ make allyesconfig all
$ mkdir build-output
$ make INSTALL_MOD_PATH=./build-output modules_install
$ cp vmlinux build-output/modules/4.5.0
$ abidw --linux-tree build-output/modules/4.5.0 > build-output/linux-4.5.0.kmi

• --headers-dir | --hd <headers-directory-path-1>

Specifies where to find the public headers of the first shared library that the tool has to
consider. The tool will thus filter out types that are not defined in public headers.

• --no-linux-kernel-mode

Without this option, if abipkgiff detects that the binaries it is looking at are Linux Kernel
binaries (either vmlinux or modules) then it only considers functions and variables which ELF
symbols are listed in the __ksymtab and __ksymtab_gpl sections.

With this option, abipkgdiff considers the binary as a non-special ELF binary. It thus considers
functions and variables which are defined and exported in the ELF sense.

• --check-alternate-debug-info <elf-path>

If the debug info for the file elf-path contains a reference to an alternate debug info file, abidw
checks that it can find that alternate debug info file. In that case, it emits a meaningful success
message mentioning the full path to the alternate debug info file found. Otherwise, it emits an
error code.

• --no-show-locs
In the emitted ABI representation, do not show file, line or column where ABI artifacts are
defined.

• --check-alternate-debug-info-base-name <elf-path>

Like --check-alternate-debug-info, but in the success message, only mention the base name of the
debug info file; not its full path.

• --load-all-types

By default, libabigail (and thus abidw) only loads types that are reachable from functions and
variables declarations that are publicly defined and exported by the binary. So only those types
are present in the output of abidw. This option however makes abidw load all the types defined in
the binaries, even those that are not reachable from public declarations.

• --abidiff
Load the ABI of the ELF binary given in argument, save it in libabigail’s XML format in a
temporary file; read the ABI from the temporary XML file and compare the ABI that has been read
back against the ABI of the ELF binary given in argument. The ABIs should compare equal. If they
don’t, the program emits a diagnostic and exits with a non-zero code.

This is a debugging and sanity check option.

• --annotate
Annotate the ABIXML output with comments above most elements. The comments are made of the
pretty-printed form types, declaration or even ELF symbols. The purpose is to make the ABIXML
output more human-readable for debugging or documenting purposes.

• --stats

Emit statistics about various internal things.

• --verbose

Emit verbose logs about the progress of miscellaneous internal things.

NOTES

   Alternate debug info files
       As of the version 4 of the DWARF specification, Alternate debug information is a  GNU  extension  to  the
       DWARF specification.  It has however been proposed for inclusion into the upcoming version 5 of the DWARF
       standard.  You can read more about the GNU extensions to the DWARF standard here.

AUTHOR

       Dodji Seketeli

COPYRIGHT

       2014-2018, Red Hat, Inc.

                                                  Apr 24, 2018                                          ABIDW(1)