Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 18 Jul 2022 11:51:01 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Jiri Olsa <olsajiri@gmail.com>
Cc:     Blake Jones <blakejones@google.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] Add a "-m" option to "perf buildid-list".
Message-ID: <YtVzVZoo5PTj0qXH@kernel.org>
References: <20220629213632.3899212-1-blakejones@google.com>
 <Yr6u/jdLvg2TcT8s@krava>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Yr6u/jdLvg2TcT8s@krava>
Precedence: bulk

Em Fri, Jul 01, 2022 at 10:23:26AM +0200, Jiri Olsa escreveu:
> On Wed, Jun 29, 2022 at 02:36:32PM -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>
> 
> Acked-by: Jiri Olsa <jolsa@kernel.org>

To clarify, b4 found v3 and that was the one applied.

Thanks,

- Arnaldo
 
> thanks,
> jirka
> 
> > ---
> >  .../perf/Documentation/perf-buildid-list.txt  |  4 ++
> >  tools/perf/builtin-buildid-list.c             | 38 ++++++++++++++++++-
> >  tools/perf/util/machine.c                     | 15 ++++++++
> >  tools/perf/util/machine.h                     |  5 +++
> >  4 files changed, 61 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..cffca6a536e9 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 +21,34 @@
> >  #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);
> > +	} else if (dso->short_name != NULL) {
> > +		printf(" %s", dso->short_name);
> > +	}
> > +	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 +128,7 @@ 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 +136,8 @@ 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 +149,12 @@ 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..16d225149b93 100644
> > --- a/tools/perf/util/machine.c
> > +++ b/tools/perf/util/machine.c
> > @@ -3327,3 +3327,18 @@ 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)) {
> > +		err = fn(map, priv);
> > +		if (err != 0) {
> > +			break;
> > +		}
> > +	}
> > +	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
> > -- 
> > 2.37.0.rc0.161.g10f37bed90-goog
> > 

-- 

- Arnaldo