Date:   Tue, 24 Nov 2020 00:05:09 +0100
From:   Jiri Olsa <jolsa@...nel.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     lkml <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Ingo Molnar <mingo@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Namhyung Kim <namhyung@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Michael Petlan <mpetlan@...hat.com>,
        Song Liu <songliubraving@...com>,
        Ian Rogers <irogers@...gle.com>,
        Stephane Eranian <eranian@...gle.com>,
        Alexey Budankov <alexey.budankov@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Adrian Hunter <adrian.hunter@...el.com>
Subject: [PATCH 22/25] perf buildid-cache: Add support to add build ids from perf data

Adding support to specify perf data file as -a option file
argument,

If the file is detected to be perf data file, it is processed
and all dso objects with sample hit are stored to the build
id cache.

  $ DEBUGINFOD_URLS=http://192.168.122.174:8002 perf buildid-cache -a perf.data
  OK   5dcec522abf136fcfd3128f47e131f2365834dd7 /home/jolsa/.debug/.build-id/5d/cec522abf136fcfd3128f47e131f2365834dd7/elf
  OK   5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko

By default we store only dso with hits, but it's possible to
specify 'all' to store all dso objects, like:
    -a perf.data,all

  $ DEBUGINFOD_URLS=http://192.168.122.174:8002 perf buildid-cache -a perf.data,all
  OK   5dcec522abf136fcfd3128f47e131f2365834dd7 /home/jolsa/.debug/.build-id/5d/cec522abf136fcfd3128f47e131f2365834dd7/elf
  OK   6ce92dc7c31f12fe5b7775a2bb8b14a3546ce2cd /lib/modules/5.10.0-rc2speed+/kernel/drivers/firmware/qemu_fw_cfg.ko
  OK   bf3f6d32dccc159f841fc3658c241d0e74c61fbb /lib/modules/5.10.0-rc2speed+/kernel/drivers/block/virtio_blk.ko
  OK   e896b4329cf9f190f1a0fae933f425ff8f71b052 /lib/modules/5.10.0-rc2speed+/kernel/drivers/char/virtio_console.ko
  OK   5bedc933cb59e053ecb472f327bd73c548364479 /lib/modules/5.10.0-rc2speed+/kernel/drivers/input/serio/serio_raw.ko
  OK   cecc506368a8b7a473a5f900d26f0d3d914a9c23 /lib/modules/5.10.0-rc2speed+/kernel/arch/x86/crypto/crc32c-intel.ko
  OK   91076fb3646d061a0a42cf7bddb339a665ee4f80 /lib/modules/5.10.0-rc2speed+/kernel/arch/x86/crypto/ghash-clmulni-intel.ko
  OK   4e2a304d788bb8e2e950bc82a5944e042afa0bf2 /lib/modules/5.10.0-rc2speed+/kernel/drivers/media/cec/core/cec.ko
  OK   31ab0da5ad81e6803280177f507a95f3053d585e /lib/modules/5.10.0-rc2speed+/kernel/lib/libcrc32c.ko
  OK   f6154bca47c149f48c942fcc3d653041dd285c65 /lib/modules/5.10.0-rc2speed+/kernel/drivers/gpu/drm/ttm/ttm.ko
  OK   723f5852de81590d54b23b38c160d3618b41951b /lib/modules/5.10.0-rc2speed+/kernel/arch/x86/crypto/crct10dif-pclmul.ko
  OK   06b1eab7f141cbc3e5a5db47909c8ab5cb242e40 /lib/modules/5.10.0-rc2speed+/kernel/drivers/gpu/drm/drm_ttm_helper.ko
  OK   38292b862cf3ff87489508fdb4895efa45780813 /lib/modules/5.10.0-rc2speed+/kernel/drivers/gpu/drm/qxl/qxl.ko
  OK   cdf51e58609bf2ce4837a7b195e0ccae0a930907 /lib/modules/5.10.0-rc2speed+/kernel/arch/x86/crypto/crc32-pclmul.ko
  OK   5ca8958388f6688452ecc2cb83d6031394c659ad /lib/modules/5.10.0-rc2speed+/kernel/drivers/gpu/drm/drm.ko
  OK   236bc4e4f38bf3559007566cb32b3dcc1bc28d2d /lib/modules/5.10.0-rc2speed+/kernel/drivers/gpu/drm/drm_kms_helper.ko
  OK   5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
  OK   66db2be3efaa43bb5a5c481986e9554e1885cc69 /usr/lib/systemd/systemd
  OK   7db607d9f2de89860d9639712da64c8bacd31e4b /usr/lib64/libm-2.30.so
  OK   55b5f9652e1d17c1dd58f62628d5063428e5db91 /usr/lib64/libudev.so.1.6.15
  OK   63b97070bf097130713bb6c89cf7100b5f3c9b17 /usr/lib64/libunistring.so.2.1.0
  ...

Once perf data is specified, no other file can be specified in
the option, otherwise it causes syntax error.

Signed-off-by: Jiri Olsa <jolsa@...nel.org>
---
 .../perf/Documentation/perf-buildid-cache.txt |  12 +-
 tools/perf/builtin-buildid-cache.c            | 215 +++++++++++++++++-
 tools/perf/util/probe-event.c                 |   6 +-
 3 files changed, 227 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-buildid-cache.txt b/tools/perf/Documentation/perf-buildid-cache.txt
index f6de0952ff3c..b77da5138bca 100644
--- a/tools/perf/Documentation/perf-buildid-cache.txt
+++ b/tools/perf/Documentation/perf-buildid-cache.txt
@@ -23,7 +23,17 @@ OPTIONS
 -------
 -a::
 --add=::
-        Add specified file to the cache.
+        Add specified file or perf.data binaries to the cache.
+
+        If the file is detected to be perf data file, it is processed
+        and all dso objects with sample hit are stored to the cache.
+
+        It's possible to specify 'all' to store all dso objects, like:
+            -a perf.data,all
+
+        Once perf data is specified, no other file can be specified in
+        the option, otherwise it causes syntax error.
+
 -f::
 --force::
 	Don't complain, do it.
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index a25411926e48..0bfb54ee1e5e 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -29,6 +29,11 @@
 #include "util/probe-file.h"
 #include <linux/string.h>
 #include <linux/err.h>
+#include <linux/zalloc.h>
+#include <sys/stat.h>
+#ifdef HAVE_DEBUGINFOD_SUPPORT
+#include <elfutils/debuginfod.h>
+#endif
 
 static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
 {
@@ -348,6 +353,205 @@ static int build_id_cache__show_all(void)
 	return 0;
 }
 
+#ifdef HAVE_DEBUGINFOD_SUPPORT
+static int call_debuginfod(const char *sbuild_id, char **path, bool debuginfo)
+{
+	debuginfod_client *c;
+	int fd;
+
+	c = debuginfod_begin();
+	if (c == NULL)
+		return -1;
+
+	pr_debug("trying debuginfod for executable <%s> ... ", sbuild_id);
+
+	if (debuginfo) {
+		fd = debuginfod_find_debuginfo(c, (const unsigned char *) sbuild_id,
+					       0, path);
+	} else {
+		fd = debuginfod_find_executable(c, (const unsigned char *) sbuild_id,
+						0, path);
+	}
+	if (fd >= 0)
+		close(fd); /* retaining reference by realname */
+
+	debuginfod_end(c);
+	pr_debug("%s%s\n", *path ? "OK " : "FAILED", *path ? *path : "");
+	return *path ? 0 : -1;
+}
+#else
+static int call_debuginfod(const char *sbuild_id __maybe_unused,
+			   char **path __maybe_unused,
+			   bool debuginfo __maybe_unused)
+{
+	return -1;
+}
+#endif
+
+struct dso_store_data {
+	bool	 hits;
+	bool	 force_download;
+};
+
+static int dso_store(struct dso *dso, struct machine *machine, void *priv)
+{
+	struct dso_store_data *data = priv;
+	char sbuild_id[SBUILD_ID_SIZE];
+	struct build_id bid;
+	char *path = NULL, *link = NULL;
+	bool is_kallsyms;
+	int err = -1;
+
+	/*
+	 * There's no build id in dso, nothing to do..
+	 */
+	if (!dso->has_build_id || !build_id__is_defined(&dso->bid))
+		return 0;
+
+	if (data->hits && !dso->hit)
+		return 0;
+
+	/*
+	 * The storing process is:
+	 *   - get build id of the dso
+	 *   - check if it is already in cache
+	 *   - check if it matches provided build id from mmap2 event
+	 *   - if not, try debuginfod to download the binary
+	 *   - store binary to build id database
+	 */
+	is_kallsyms = !strcmp(machine->mmap_name, dso->short_name);
+	build_id__sprintf(&dso->bid, sbuild_id);
+
+	link = build_id_cache__linkname(sbuild_id, NULL, 0);
+	if (!link)
+		return -ENOMEM;
+
+	if (!data->force_download && !access(link, X_OK)) {
+		pr_debug("already in cache - %s <%s>\n", dso->long_name, sbuild_id);
+		err = 0;
+		goto out;
+	}
+
+	path = strdup(dso->long_name);
+	if (!path)
+		goto out;
+
+	if (is_kallsyms) {
+		/*
+		 * Find out if we are on the same kernel as perf.data
+		 * and store kallsyms in that case.
+		 */
+		err = sysfs__read_build_id("/sys/kernel/notes", &bid);
+		if (err < 0)
+			goto out;
+	} else {
+		struct nscookie nsc;
+		struct stat st;
+
+		nsinfo__mountns_enter(dso->nsinfo, &nsc);
+
+		/*
+		 * Does the file exists in the first place, if it does,
+		 * resolve path and read the build id.
+		 */
+		if (stat(dso->long_name, &st)) {
+			nsinfo__mountns_exit(&nsc);
+			zfree(&path);
+			goto try_download;
+		}
+
+		err = filename__read_build_id(dso->long_name, &bid);
+		nsinfo__mountns_exit(&nsc);
+
+		if (err <= 0)
+			goto out;
+	}
+
+	/*
+	 * If we match, then what we want in mmap2 event
+	 * is what we got in the binary,
+	 */
+	if (bid.size != dso->bid.size || memcmp(&bid, &dso->bid, bid.size)) {
+		char sbid[SBUILD_ID_SIZE];
+
+		build_id__sprintf(&bid, sbid);
+		pr_debug("mmap build id <%s> does not match for %s <%s>\n",
+			 sbuild_id, path, sbid);
+		zfree(&path);
+	}
+
+try_download:
+	/*
+	 * We did not match build id or did not find the
+	 * binary - try debuginfod as last resort.
+	 */
+	if (!path) {
+		bool debuginfo;
+		char *tmp = NULL;
+
+		/*
+		 * The debuginfo retrieval for standard binaries
+		 * is handled within build_id_cache__add function.
+		 *
+		 * For kernel and kernel modules we have to ask
+		 * for debuginfo directly, because debuginfod
+		 * does not treat them as binaries.
+		 */
+		debuginfo = is_kallsyms ||
+			    is_kernel_module(dso->long_name, PERF_RECORD_MISC_CPUMODE_UNKNOWN);
+
+		if (call_debuginfod(sbuild_id, &tmp, debuginfo)) {
+			err = -1;
+			goto out;
+		}
+
+		path = tmp;
+
+		/*
+		 * The kernel dso is now elf binary, so disable is_kallsyms
+		 * so build_id_cache__add can prepare proper file names.
+		 */
+		is_kallsyms = false;
+	}
+
+	pr_debug("linking %s %s <%s>\n", dso->short_name, path, sbuild_id);
+
+	err = build_id_cache__add(sbuild_id, path, path,
+				  dso->nsinfo, is_kallsyms, false);
+out:
+	free(path);
+	fprintf(stderr, "%s %s %s\n", err ? "FAIL" : "OK  ", sbuild_id, dso->long_name);
+	return 0;
+}
+
+static int
+build_id_cache__add_perf_data(const char *path, bool all)
+{
+	struct perf_session *session;
+	struct dso_store_data priv = {
+		.hits = !all,
+		.force_download = false,
+	};
+	struct perf_data data = {
+		.path  = path,
+		.mode  = PERF_DATA_MODE_READ,
+	};
+	int err;
+
+	session = perf_session__new(&data, false, &build_id__mark_dso_hit_ops);
+	if (IS_ERR(session))
+		return PTR_ERR(session);
+
+	err = perf_session__process_events(session);
+	if (err)
+		goto out;
+
+	err = __perf_session__cache_build_ids(session, dso_store, &priv);
+out:
+	perf_session__delete(session);
+	return err;
+}
+
 int cmd_buildid_cache(int argc, const char **argv)
 {
 	struct strlist *list;
@@ -440,7 +644,15 @@ int cmd_buildid_cache(int argc, const char **argv)
 		list = strlist__new(add_name_list_str, NULL);
 		if (list) {
 			strlist__for_each_entry(pos, list)
-				if (build_id_cache__add_file(pos->s, nsi)) {
+				if (is_perf_data(pos->s)) {
+					struct str_node *all_pos = strlist__next(pos);
+					bool all = !strcmp("all", all_pos ? all_pos->s : "");
+
+					if (build_id_cache__add_perf_data(pos->s, all))
+						pr_warning("Couldn't add build ids from %s\n", pos->s);
+					if (all)
+						pos = all_pos;
+				} else if (build_id_cache__add_file(pos->s, nsi)) {
 					if (errno == EEXIST) {
 						pr_debug("%s already in the cache\n",
 							 pos->s);
@@ -449,7 +661,6 @@ int cmd_buildid_cache(int argc, const char **argv)
 					pr_warning("Couldn't add %s: %s\n",
 						   pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
 				}
-
 			strlist__delete(list);
 		}
 	}
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 8eae2afff71a..e821bb977c9b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1616,9 +1616,9 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 		return -EINVAL;
 	}
 
-	pr_debug("symbol:%s file:%s line:%d offset:%lu return:%d lazy:%s\n",
-		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
-		 pp->lazy_line);
+	pr_debug2("symbol:%s file:%s line:%d offset:%lu return:%d lazy:%s\n",
+		  pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
+		  pp->lazy_line);
 	return 0;
 }
 
-- 
2.26.2

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