Ubuntu Manpage: debuginfod-find - request debuginfo-related data

NAME

       debuginfod-find - request debuginfo-related data

SYNOPSIS

       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
       debuginfod-find [OPTION]... metadata KEY VALUE

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 un‐
stripped 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 direc‐
tory 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
../bar/foo.c AT_comp_dir=/zoo/ source BUILDID /zoo//../bar/foo.c

metadata KEY VALUE
All designated debuginfod servers are queried for metadata about all files that match a given key/value
query in their index. The results include names and buildids, which may be used in future queries to
fetch actual files.

KEY VALUE DESCRIPTION

file path exact match path, including in archives
glob pattern shell-style glob match pattern, including in archives, as in fnmatch(FNM_PATHNAME)

The resulting output will look something like the following {
"results":[
{
"type":"executable",
"buildid":"f0aa15b8aba4f3c28cac3c2a73801fefa644a9f2",
"file":"/usr/local/bin/hello",
"archive":"/opt/elfutils/tests/test-2290642/R/rhel7/hello2-1.0-2.x86_64.rpm"
},
{
"type":"executable",
"buildid":"bc1febfd03ca05e030f0d205f7659db29f8a4b30",
"file":"hello2"
}
],
"complete":true }'

The results of the search are output to stdout as a JSON object containing an array of objects, supplying
metadata about each match, as well as a boolean value corresponding to the completeness of the result.
The result is considered complete if all of the queries to upstream servers returned complete results and
the local query succeeded. This metadata report may be cached. It may be incomplete and may contain du‐
plicates. Additional JSON object fields may be present.

NAME TYPE DESCRIPTION

buildid string hexadecimal buildid associated with the file
type string one of debuginfo or executable
file string matched file name, outside or inside the archive
archive string archive containing matched file name, if any

It's worth noting that type cannot be source since in order to perform such a search fast enough addi‐
tional indexing would need to be added to the database which would nearly double it's size.

The search also always combines both files and archives in the results and at this time further granular‐
ity is not availible.

OPTIONS

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

SECURITY

       If IMA signature(s) are available from the RPMs that contain requested files, then  debuginfod  will  ex‐
       tract  those  signatures  into  response  headers, and debuginfod-find will perform verification upon the
       files.  Validation policy is controlled via tags inserted into $DEBUGINFOD_URLS.  By default, debuginfod-
       find acts in ignore mode.

       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.)

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

SECURITY

SEE ALSO