lkml.org 
[lkml]   [2022]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 RESEND] Add a "-m" option to "perf buildid-list".
On Mon, Jun 27, 2022 at 03:41:16PM -0700, Blake Jones wrote:
> 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
> [...]
>
> Signed-off-by: Blake Jones <blakejones@google.com>
> ---
> .../perf/Documentation/perf-buildid-list.txt | 4 +++
> tools/perf/builtin-buildid-list.c | 35 ++++++++++++++++++-
> tools/perf/util/machine.c | 13 +++++++
> tools/perf/util/machine.h | 5 +++
> 4 files changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/Documentation/perf-buildid-list.txt b/tools/perf/Documentation/perf-buildid-list.txt
> index 25c52efcc7f0..e1e8fdbe06b9 100644
> --- a/tools/perf/Documentation/perf-buildid-list.txt
> +++ b/tools/perf/Documentation/perf-buildid-list.txt
> @@ -33,6 +33,10 @@ OPTIONS
> -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.
> diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
> index cebadd632234..e73520190974 100644
> --- a/tools/perf/builtin-buildid-list.c
> +++ b/tools/perf/builtin-buildid-list.c
> @@ -12,6 +12,7 @@
> #include "util/build-id.h"
> #include "util/debug.h"
> #include "util/dso.h"
> +#include "util/map.h"
> #include <subcmd/pager.h>
> #include <subcmd/parse-options.h>
> #include "util/session.h"
> @@ -20,6 +21,31 @@
> #include <errno.h>
> #include <linux/err.h>
>
> +static int buildid__map_cb(struct map *map, void *arg __maybe_unused)
> +{
> + const struct dso *dso = map->dso;
> + char bid_buf[SBUILD_ID_SIZE];
> +
> + memset(bid_buf, 0, sizeof(bid_buf));
> + if (dso->has_build_id)
> + build_id__sprintf(&dso->bid, bid_buf);
> + printf("%s %16lx %16lx", bid_buf, map->start, map->end);
> + if (dso->long_name != NULL)
> + printf(" %s", dso->long_name);

nit, should we display short_name in case long_name is missing?

> + printf("\n");
> +
> + return 0;
> +}
> +
> +static void buildid__show_kernel_maps(void)
> +{
> + struct machine *machine;
> +
> + machine = machine__new_host();
> + machine__for_each_kernel_map(machine, buildid__map_cb, NULL);
> + machine__delete(machine);
> +}
> +
> static int sysfs__fprintf_build_id(FILE *fp)
> {
> char sbuild_id[SBUILD_ID_SIZE];
> @@ -99,6 +125,7 @@ static int perf_session__list_build_ids(bool force, bool with_hits)
> int cmd_buildid_list(int argc, const char **argv)
> {
> bool show_kernel = false;
> + bool show_kernel_maps = false;
> bool with_hits = false;
> bool force = false;
> const struct option options[] = {
> @@ -106,6 +133,8 @@ int cmd_buildid_list(int argc, const char **argv)
> OPT_STRING('i', "input", &input_name, "file", "input file name"),
> OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
> OPT_BOOLEAN('k', "kernel", &show_kernel, "Show current kernel build id"),
> + OPT_BOOLEAN('m', "kernel-maps", &show_kernel_maps,
> + "Show build id of current kernel + modules"),
> OPT_INCR('v', "verbose", &verbose, "be more verbose"),
> OPT_END()
> };
> @@ -117,8 +146,12 @@ int cmd_buildid_list(int argc, const char **argv)
> argc = parse_options(argc, argv, options, buildid_list_usage, 0);
> setup_pager();
>
> - if (show_kernel)
> + if (show_kernel) {
> return !(sysfs__fprintf_build_id(stdout) > 0);
> + } else if (show_kernel_maps) {
> + buildid__show_kernel_maps();
> + return 0;
> + }
>
> return perf_session__list_build_ids(force, with_hits);
> }
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 009061852808..28fff9a02ab0 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -3327,3 +3327,16 @@ int machine__for_each_dso(struct machine *machine, machine__dso_t fn, void *priv
> }
> return err;
> }
> +
> +int machine__for_each_kernel_map(struct machine *machine, machine__map_t fn, void *priv)
> +{
> + struct maps *maps = machine__kernel_maps(machine);
> + struct map *map;
> + int err = 0;
> +
> + for (map = maps__first(maps); map != NULL; map = map__next(map)) {
> + if (fn(map, priv))
> + err = -1;

I think we should rather break in here and return user's error
other than that, the patch looks good to me

thanks,
jirka

> + }
> + return err;
> +}
> diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
> index 5d7daf7cb7bc..e1476343cbb2 100644
> --- a/tools/perf/util/machine.h
> +++ b/tools/perf/util/machine.h
> @@ -262,6 +262,11 @@ typedef int (*machine__dso_t)(struct dso *dso, struct machine *machine, void *pr
>
> int machine__for_each_dso(struct machine *machine, machine__dso_t fn,
> void *priv);
> +
> +typedef int (*machine__map_t)(struct map *map, void *priv);
> +int machine__for_each_kernel_map(struct machine *machine, machine__map_t fn,
> + void *priv);
> +
> int machine__for_each_thread(struct machine *machine,
> int (*fn)(struct thread *thread, void *p),
> void *priv);
>
> base-commit: 1bcca2b1bd67f3c0e5c3a88ed16c6389f01a5b31
> --
> 2.36.1.476.g0c4daa206d-goog
>

\
 
 \ /
  Last update: 2022-06-29 11:40    [W:0.091 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site