hi, currently we support only one storage size (20 bytes) for build ids. That fits for SHA1 build ids, but there can in theory be any size. The gcc linker supports also MD5, which is 16 bytes.
Currently the MD5 build id will be stored in .debug cache with additional zeros, like: $ find ~/.debug .../.debug/.build-id/a5/0e350e97c43b4708d09bcd85ebfff700000000 ... .../buildid-ex-md5/a50e350e97c43b4708d09bcd85ebfff700000000 .../buildid-ex-md5/a50e350e97c43b4708d09bcd85ebfff700000000/elf .../buildid-ex-md5/a50e350e97c43b4708d09bcd85ebfff700000000/probes And the same reflected in buildid-list as well: $ perf buildid-list 17f4e448cc746582ea1881528deb549f7fdb3fd5 [kernel.kallsyms] a50e350e97c43b4708d09bcd85ebfff700000000 .../buildid-ex-md5 This will cause problems in future when we will ask debuginfod for binaries/debuginfo based on build id. This patchset is adding 'struct build_id' object, that holds the build id data and size and use it to store build ids and changes all related functions to use it. Also available in: git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git perf/build_id_size v2 changes: - rebased on current perf/core - updated test to build its own binaries [Namhyung] thanks, jirka --- Jiri Olsa (9): perf tools: Use build_id object in dso perf tools: Pass build_id object to filename__read_build_id perf tools: Pass build id object to sysfs__read_build_id perf tools: Pass build_id object to build_id__sprintf perf tools: Pass build_id object to dso__set_build_id perf tools: Pass build_id object to dso__build_id_equal perf tools: Add size to struct perf_record_header_build_id perf tools: Align buildid list output for short build ids perf tools: Add build id shell test tools/lib/perf/include/perf/event.h | 12 +++++++++++- tools/perf/bench/inject-buildid.c | 4 ++-- tools/perf/builtin-buildid-cache.c | 25 ++++++++++++------------ tools/perf/builtin-inject.c | 4 +--- tools/perf/tests/pe-file-parsing.c | 10 +++++----- tools/perf/tests/sdt.c | 6 +++--- tools/perf/tests/shell/buildid.sh | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/annotate.c | 3 +-- tools/perf/util/build-id.c | 48 +++++++++++++++++++++++++++------------------- tools/perf/util/build-id.h | 8 +++++++- tools/perf/util/dso.c | 23 ++++++++++------------ tools/perf/util/dso.h | 7 +++---- tools/perf/util/dsos.c | 9 +++++---- tools/perf/util/header.c | 15 ++++++++++----- tools/perf/util/map.c | 4 +--- tools/perf/util/probe-event.c | 9 ++++++--- tools/perf/util/probe-finder.c | 8 +++++--- tools/perf/util/scripting-engines/trace-event-python.c | 2 +- tools/perf/util/symbol-elf.c | 35 +++++++++++++++++++-------------- tools/perf/util/symbol-minimal.c | 31 +++++++++++++++--------------- tools/perf/util/symbol.c | 15 +++++++-------- tools/perf/util/symbol.h | 5 +++-- tools/perf/util/synthetic-events.c | 2 +- 23 files changed, 260 insertions(+), 126 deletions(-) create mode 100755 tools/perf/tests/shell/buildid.sh