debuginfod-find - Man Page

request debuginfo-related data

Examples (TL;DR)

Request data based on the build_id: debuginfod-find -vv debuginfo build_id

debuginfod-find [OPTION]... debuginfo BUILDID debuginfod-find [OPTION]... debuginfo PATH debuginfod-find [OPTION]... executable BUILDID debuginfod-find [OPTION]... executable PATH debuginfod-find [OPTION]... source BUILDID /FILENAME debuginfod-find [OPTION]... source PATH /FILENAME

Description

debuginfod-find queries one or more debuginfod servers for debuginfo-related data. In case of a match, it saves the the requested file into a local cache, prints the file name to standard output, and exits with a success status of 0. In case of any error, it exits with a failure status and an error message to standard error.

The debuginfod system uses buildids to identify debuginfo-related data. These are stored as binary notes in ELF/DWARF files, and are represented as lowercase hexadecimal. For example, for a program /bin/ls, look at the ELF note GNU_BUILD_ID:

% readelf -n /bin/ls | grep -A4 build.id
Note section [ 4] '.note.gnu.buildid' of 36 bytes at offset 0x340:
Owner          Data size  Type
GNU                   20  GNU_BUILD_ID
Build ID: 8713b9c3fb8a720137a4a08b325905c7aaf8429d

Then the hexadecimal BUILDID is simply:

8713b9c3fb8a720137a4a08b325905c7aaf8429d

In place of the hexadecimal BUILDID, debuginfod-find also accepts a path name to to an ELF binary, from which it extracts the buildid. In this case, ensure the file name has some character other than [0-9a-f]. Files ambiguously named files like "deadbeef" can be passed with a ./deadbeef extra path component.

debuginfo BUILDID

If the given buildid is known to a server, this request will result in a binary object that contains the customary .*debug_* sections. This may be a split debuginfo file as created by strip, or it may be an original unstripped executable.

executable BUILDID

If the given buildid is known to the server, this request will result in a binary object that contains the normal executable segments. This may be a executable stripped by strip, or it may be an original unstripped executable. ET_DYN shared libraries are considered to be a type of executable.

source BUILDID /SOURCE/FILE

If the given buildid is known to the server, this request will result in a binary object that contains the source file mentioned. The path should be absolute. Relative path names commonly appear in the DWARF file's source directory, but these paths are relative to individual compilation unit AT_comp_dir paths, and yet an executable is made up of multiple CUs. Therefore, to disambiguate, debuginfod expects source queries to prefix relative path names with the CU compilation-directory, followed by a mandatory "/".

Note: for software packaged by distributions, the CU compilation-directory may not be obvious. It can be found by inspecting AT_comp_dir values in downloaded debuginfo. For example, the comp_dir of the Fedora 37 version of /bin/ls can be found as follows:

% debuginfod-find debuginfo /bin/ls
~/.cache/debuginfod_client/03529d48345409576cd5c82a56ad08555088d353/
% eu-readelf -w ~/.cache/debuginfod_client/03529d48345409576cd5c82a56ad08555088d353/debuginfo | grep comp_dir
           comp_dir             (line_strp) "/usr/src/debug/coreutils-9.1-6.fc37.x86_64/separate"

Note: the caller may or may not elide ../ or /./ or extraneous /// sorts of path components in the directory names. debuginfod accepts both forms. Specifically, debuginfod canonicalizes path names according to RFC3986 section 5.2.4 (Remove Dot Segments), plus reducing any // to / in the path.

For example:

#include <stdio.h>	source BUILDID /usr/include/stdio.h
/path/to/foo.c	source BUILDID /path/to/foo.c

Options

-v: Increase verbosity, including printing frequent download-progress messages and printing the http response headers from the server.

Security

debuginfod-find does not include any particular security features. It trusts that the binaries returned by the debuginfod(s) are accurate. Therefore, the list of servers should include only trustworthy ones. If accessed across HTTP rather than HTTPS, the network should be trustworthy. Authentication information through the internal libcurl library is not currently enabled, except for the basic plaintext http[s]://userid:password@hostname/ style. (The debuginfod server does not perform authentication, but a front-end proxy server could.)

Referenced By

debuginfod(8), debuginfod.service(8).