linux-stable/tools/perf/Documentation/perf-buildid-list.txt
Blake Jones a6bd98c45d perf buildid-list: Add a "-m" option to show kernel and modules build-ids
This new option displays all of the information needed to do external
BuildID-based symbolization of kernel stack traces, such as those collected
by bpf_get_stackid().

For each kernel module plus the main kernel, it displays the BuildID,
the start and end virtual addresses of that module's text range (rounded
out to page boundaries), and the pathname of the module.

When run as a non-privileged user, the actual addresses of the modules'
text ranges are not available, so the tools displays "0, <text length>" for
kernel modules and "0, 0xffffffffffffffff" for the kernel itself.

Sample output:

  root# perf buildid-list -m
  cf6df852fd4da122d616153353cc8f560fd12fe0 ffffffffa5400000 ffffffffa6001e27 [kernel.kallsyms]
  1aa7209aa2acb067d66ed6cf7676d65066384d61 ffffffffc0087000 ffffffffc008b000 /lib/modules/5.15.15-1rodete2-amd64/kernel/crypto/sha512_generic.ko
  3857815b5bf0183697b68f8fe0ea06121644041e ffffffffc008c000 ffffffffc0098000 /lib/modules/5.15.15-1rodete2-amd64/kernel/arch/x86/crypto/sha512-ssse3.ko
  4081fde0bca2bc097cb3e9d1efcb836047d485f1 ffffffffc0099000 ffffffffc009f000 /lib/modules/5.15.15-1rodete2-amd64/kernel/drivers/acpi/button.ko
  1ef81ba4890552ea6b0314f9635fc43fc8cef568 ffffffffc00a4000 ffffffffc00aa000 /lib/modules/5.15.15-1rodete2-amd64/kernel/crypto/cryptd.ko
  cc5c985506cb240d7d082b55ed260cbb851f983e ffffffffc00af000 ffffffffc00b6000 /lib/modules/5.15.15-1rodete2-amd64/kernel/drivers/i2c/busses/i2c-piix4.ko
  [...]

Committer notes:

u64 formatter should be PRIx64 for printing as hex numbers, fix this:

  28     5.28 debian:experimental-x-mips    : FAIL gcc version 11.2.0 (Debian 11.2.0-18)
    builtin-buildid-list.c: In function 'buildid__map_cb':
    builtin-buildid-list.c:32:24: error: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=]
       32 |         printf("%s %16lx %16lx", bid_buf, map->start, map->end);
          |                    ~~~~^                  ~~~~~~~~~~
          |                        |                     |
          |                        long unsigned int     u64 {aka long long unsigned int}
          |                    %16llx
    builtin-buildid-list.c:32:30: error: format '%lx' expects argument of type 'long unsigned int', but argument 4 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=]
       32 |         printf("%s %16lx %16lx", bid_buf, map->start, map->end);
          |                          ~~~~^                        ~~~~~~~~
          |                              |                           |
          |                              long unsigned int           u64 {aka long long unsigned int}
          |                          %16llx
    cc1: all warnings being treated as errors

Signed-off-by: Blake Jones <blakejones@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220629213632.3899212-1-blakejones@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-07-18 16:35:34 -03:00

47 lines
936 B
Text

perf-buildid-list(1)
====================
NAME
----
perf-buildid-list - List the buildids in a perf.data file
SYNOPSIS
--------
[verse]
'perf buildid-list <options>'
DESCRIPTION
-----------
This command displays the buildids found in a perf.data file, so that other
tools can be used to fetch packages with matching symbol tables for use by
perf report.
It can also be used to show the build id of the running kernel or in an ELF
file using -i/--input.
OPTIONS
-------
-H::
--with-hits::
Show only DSOs with hits.
-i::
--input=::
Input file name. (default: perf.data unless stdin is a fifo)
-f::
--force::
Don't do ownership validation.
-k::
--kernel::
Show running kernel build id.
-m::
--kernel-maps::
Show buildid, start/end text address, and path of running kernel and
its modules.
-v::
--verbose::
Be more verbose.
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-top[1],
linkperf:perf-report[1]