perf buildid-cache: Support binary objects from other namespaces

Teach buildid-cache how to add, remove, and update binary objects from
other mount namespaces.  Allow probe events tracing binaries in
different namespaces to add their objects to the probe and build-id
caches too.  As a handy side effect, this also lets us access SDT probes
in binaries from alternate mount namespaces.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-5-git-send-email-kjlx@templeofstupid.com
[ Add util/namespaces.c to tools/perf/util/python-ext-sources, to fix the python binding 'perf test' ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 37 insertions, 15 deletions

diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index 9eba7f1add1f..d65bd86bee99 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include "builtin.h"
 #include "perf.h"
+#include "namespaces.h"
 #include "util/cache.h"
 #include "util/debug.h"
 #include "util/header.h"
@@ -165,33 +166,41 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	return 0;
 }
 
-static int build_id_cache__add_file(const char *filename)
+static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
 	u8 build_id[BUILD_ID_SIZE];
 	int err;
+	struct nscookie nsc;
 
-	if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
+	nsinfo__mountns_enter(nsi, &nsc);
+	err = filename__read_build_id(filename, &build_id, sizeof(build_id));
+	nsinfo__mountns_exit(&nsc);
+	if (err < 0) {
 		pr_debug("Couldn't read a build-id in %s\n", filename);
 		return -1;
 	}
 
 	build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
-	err = build_id_cache__add_s(sbuild_id, filename,
+	err = build_id_cache__add_s(sbuild_id, filename, nsi,
 				    false, false);
 	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
 		 err ? "FAIL" : "Ok");
 	return err;
 }
 
-static int build_id_cache__remove_file(const char *filename)
+static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
 {
 	u8 build_id[BUILD_ID_SIZE];
 	char sbuild_id[SBUILD_ID_SIZE];
+	struct nscookie nsc;
 
 	int err;
 
-	if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
+	nsinfo__mountns_enter(nsi, &nsc);
+	err = filename__read_build_id(filename, &build_id, sizeof(build_id));
+	nsinfo__mountns_exit(&nsc);
+	if (err < 0) {
 		pr_debug("Couldn't read a build-id in %s\n", filename);
 		return -1;
 	}
@@ -204,13 +213,13 @@ static int build_id_cache__remove_file(const char *filename)
 	return err;
 }
 
-static int build_id_cache__purge_path(const char *pathname)
+static int build_id_cache__purge_path(const char *pathname, struct nsinfo *nsi)
 {
 	struct strlist *list;
 	struct str_node *pos;
 	int err;
 
-	err = build_id_cache__list_build_ids(pathname, &list);
+	err = build_id_cache__list_build_ids(pathname, nsi, &list);
 	if (err)
 		goto out;
 
@@ -256,24 +265,30 @@ static int build_id_cache__fprintf_missing(struct perf_session *session, FILE *f
 	return 0;
 }
 
-static int build_id_cache__update_file(const char *filename)
+static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
 {
 	u8 build_id[BUILD_ID_SIZE];
 	char sbuild_id[SBUILD_ID_SIZE];
+	struct nscookie nsc;
 
-	int err = 0;
+	int err;
 
-	if (filename__read_build_id(filename, &build_id, sizeof(build_id)) < 0) {
+	nsinfo__mountns_enter(nsi, &nsc);
+	err = filename__read_build_id(filename, &build_id, sizeof(build_id));
+	nsinfo__mountns_exit(&nsc);
+	if (err < 0) {
 		pr_debug("Couldn't read a build-id in %s\n", filename);
 		return -1;
 	}
+	err = 0;
 
 	build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 	if (build_id_cache__cached(sbuild_id))
 		err = build_id_cache__remove_s(sbuild_id);
 
 	if (!err)
-		err = build_id_cache__add_s(sbuild_id, filename, false, false);
+		err = build_id_cache__add_s(sbuild_id, filename, nsi, false,
+					    false);
 
 	pr_debug("Updating %s %s: %s\n", sbuild_id, filename,
 		 err ? "FAIL" : "Ok");
@@ -286,6 +301,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 	struct strlist *list;
 	struct str_node *pos;
 	int ret = 0;
+	int ns_id = -1;
 	bool force = false;
 	char const *add_name_list_str = NULL,
 		   *remove_name_list_str = NULL,
@@ -299,6 +315,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 		.mode  = PERF_DATA_MODE_READ,
 	};
 	struct perf_session *session = NULL;
+	struct nsinfo *nsi = NULL;
 
 	const struct option buildid_cache_options[] = {
 	OPT_STRING('a', "add", &add_name_list_str,
@@ -315,6 +332,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 	OPT_STRING('u', "update", &update_name_list_str, "file list",
 		    "file(s) to update"),
 	OPT_INCR('v', "verbose", &verbose, "be more verbose"),
+	OPT_INTEGER(0, "target-ns", &ns_id, "target pid for namespace context"),
 	OPT_END()
 	};
 	const char * const buildid_cache_usage[] = {
@@ -330,6 +348,9 @@ int cmd_buildid_cache(int argc, const char **argv)
 		     !missing_filename && !update_name_list_str))
 		usage_with_options(buildid_cache_usage, buildid_cache_options);
 
+	if (ns_id > 0)
+		nsi = nsinfo__new(ns_id);
+
 	if (missing_filename) {
 		file.path = missing_filename;
 		file.force = force;
@@ -348,7 +369,7 @@ 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)) {
+				if (build_id_cache__add_file(pos->s, nsi)) {
 					if (errno == EEXIST) {
 						pr_debug("%s already in the cache\n",
 							 pos->s);
@@ -366,7 +387,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 		list = strlist__new(remove_name_list_str, NULL);
 		if (list) {
 			strlist__for_each_entry(pos, list)
-				if (build_id_cache__remove_file(pos->s)) {
+				if (build_id_cache__remove_file(pos->s, nsi)) {
 					if (errno == ENOENT) {
 						pr_debug("%s wasn't in the cache\n",
 							 pos->s);
@@ -384,7 +405,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 		list = strlist__new(purge_name_list_str, NULL);
 		if (list) {
 			strlist__for_each_entry(pos, list)
-				if (build_id_cache__purge_path(pos->s)) {
+				if (build_id_cache__purge_path(pos->s, nsi)) {
 					if (errno == ENOENT) {
 						pr_debug("%s wasn't in the cache\n",
 							 pos->s);
@@ -405,7 +426,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 		list = strlist__new(update_name_list_str, NULL);
 		if (list) {
 			strlist__for_each_entry(pos, list)
-				if (build_id_cache__update_file(pos->s)) {
+				if (build_id_cache__update_file(pos->s, nsi)) {
 					if (errno == ENOENT) {
 						pr_debug("%s wasn't in the cache\n",
 							 pos->s);
@@ -424,6 +445,7 @@ int cmd_buildid_cache(int argc, const char **argv)
 
 out:
 	perf_session__delete(session);
+	nsinfo__zput(nsi);
 
 	return ret;
 }