1 files changed, 160 insertions, 66 deletions

diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
index 285d6f30d912..cb185c5659d6 100644
--- a/tools/perf/util/namespaces.c
+++ b/tools/perf/util/namespaces.c
@@ -60,22 +60,54 @@ void namespaces__free(struct namespaces *namespaces)
 	free(namespaces);
 }
 
+static int nsinfo__get_nspid(pid_t *tgid, pid_t *nstgid, bool *in_pidns, const char *path)
+{
+	FILE *f = NULL;
+	char *statln = NULL;
+	size_t linesz = 0;
+	char *nspid;
+
+	f = fopen(path, "r");
+	if (f == NULL)
+		return -1;
+
+	while (getline(&statln, &linesz, f) != -1) {
+		/* Use tgid if CONFIG_PID_NS is not defined. */
+		if (strstr(statln, "Tgid:") != NULL) {
+			*tgid = (pid_t)strtol(strrchr(statln, '\t'), NULL, 10);
+			*nstgid = *tgid;
+		}
+
+		if (strstr(statln, "NStgid:") != NULL) {
+			nspid = strrchr(statln, '\t');
+			*nstgid = (pid_t)strtol(nspid, NULL, 10);
+			/*
+			 * If innermost tgid is not the first, process is in a different
+			 * PID namespace.
+			 */
+			*in_pidns = (statln + sizeof("NStgid:") - 1) != nspid;
+			break;
+		}
+	}
+
+	fclose(f);
+	free(statln);
+	return 0;
+}
+
 int nsinfo__init(struct nsinfo *nsi)
 {
 	char oldns[PATH_MAX];
 	char spath[PATH_MAX];
 	char *newns = NULL;
-	char *statln = NULL;
 	struct stat old_stat;
 	struct stat new_stat;
-	FILE *f = NULL;
-	size_t linesz = 0;
 	int rv = -1;
 
 	if (snprintf(oldns, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
 		return rv;
 
-	if (asprintf(&newns, "/proc/%d/ns/mnt", nsi->pid) == -1)
+	if (asprintf(&newns, "/proc/%d/ns/mnt", nsinfo__pid(nsi)) == -1)
 		return rv;
 
 	if (stat(oldns, &old_stat) < 0)
@@ -88,45 +120,37 @@ int nsinfo__init(struct nsinfo *nsi)
 	 * want to switch as part of looking up dso/map data.
 	 */
 	if (old_stat.st_ino != new_stat.st_ino) {
-		nsi->need_setns = true;
-		nsi->mntns_path = newns;
+		RC_CHK_ACCESS(nsi)->need_setns = true;
+		RC_CHK_ACCESS(nsi)->mntns_path = newns;
 		newns = NULL;
 	}
 
 	/* If we're dealing with a process that is in a different PID namespace,
 	 * attempt to work out the innermost tgid for the process.
 	 */
-	if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsi->pid) >= PATH_MAX)
+	if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsinfo__pid(nsi)) >= PATH_MAX)
 		goto out;
 
-	f = fopen(spath, "r");
-	if (f == NULL)
-		goto out;
-
-	while (getline(&statln, &linesz, f) != -1) {
-		/* Use tgid if CONFIG_PID_NS is not defined. */
-		if (strstr(statln, "Tgid:") != NULL) {
-			nsi->tgid = (pid_t)strtol(strrchr(statln, '\t'),
-						     NULL, 10);
-			nsi->nstgid = nsi->tgid;
-		}
-
-		if (strstr(statln, "NStgid:") != NULL) {
-			nsi->nstgid = (pid_t)strtol(strrchr(statln, '\t'),
-						     NULL, 10);
-			break;
-		}
-	}
-	rv = 0;
+	rv = nsinfo__get_nspid(&RC_CHK_ACCESS(nsi)->tgid, &RC_CHK_ACCESS(nsi)->nstgid,
+			       &RC_CHK_ACCESS(nsi)->in_pidns, spath);
 
 out:
-	if (f != NULL)
-		(void) fclose(f);
-	free(statln);
 	free(newns);
 	return rv;
 }
 
+static struct nsinfo *nsinfo__alloc(void)
+{
+	struct nsinfo *res;
+	RC_STRUCT(nsinfo) *nsi;
+
+	nsi = calloc(1, sizeof(*nsi));
+	if (ADD_RC_CHK(res, nsi))
+		refcount_set(&nsi->refcnt, 1);
+
+	return res;
+}
+
 struct nsinfo *nsinfo__new(pid_t pid)
 {
 	struct nsinfo *nsi;
@@ -134,68 +158,117 @@ struct nsinfo *nsinfo__new(pid_t pid)
 	if (pid == 0)
 		return NULL;
 
-	nsi = calloc(1, sizeof(*nsi));
-	if (nsi != NULL) {
-		nsi->pid = pid;
-		nsi->tgid = pid;
-		nsi->nstgid = pid;
-		nsi->need_setns = false;
-		/* Init may fail if the process exits while we're trying to look
-		 * at its proc information.  In that case, save the pid but
-		 * don't try to enter the namespace.
-		 */
-		if (nsinfo__init(nsi) == -1)
-			nsi->need_setns = false;
+	nsi = nsinfo__alloc();
+	if (!nsi)
+		return NULL;
 
-		refcount_set(&nsi->refcnt, 1);
-	}
+	RC_CHK_ACCESS(nsi)->pid = pid;
+	RC_CHK_ACCESS(nsi)->tgid = pid;
+	RC_CHK_ACCESS(nsi)->nstgid = pid;
+	nsinfo__clear_need_setns(nsi);
+	RC_CHK_ACCESS(nsi)->in_pidns = false;
+	/* Init may fail if the process exits while we're trying to look at its
+	 * proc information. In that case, save the pid but don't try to enter
+	 * the namespace.
+	 */
+	if (nsinfo__init(nsi) == -1)
+		nsinfo__clear_need_setns(nsi);
 
 	return nsi;
 }
 
-struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
+static const char *nsinfo__mntns_path(const struct nsinfo *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->mntns_path;
+}
+
+struct nsinfo *nsinfo__copy(const struct nsinfo *nsi)
 {
 	struct nsinfo *nnsi;
 
 	if (nsi == NULL)
 		return NULL;
 
-	nnsi = calloc(1, sizeof(*nnsi));
-	if (nnsi != NULL) {
-		nnsi->pid = nsi->pid;
-		nnsi->tgid = nsi->tgid;
-		nnsi->nstgid = nsi->nstgid;
-		nnsi->need_setns = nsi->need_setns;
-		if (nsi->mntns_path) {
-			nnsi->mntns_path = strdup(nsi->mntns_path);
-			if (!nnsi->mntns_path) {
-				free(nnsi);
-				return NULL;
-			}
+	nnsi = nsinfo__alloc();
+	if (!nnsi)
+		return NULL;
+
+	RC_CHK_ACCESS(nnsi)->pid = nsinfo__pid(nsi);
+	RC_CHK_ACCESS(nnsi)->tgid = nsinfo__tgid(nsi);
+	RC_CHK_ACCESS(nnsi)->nstgid = nsinfo__nstgid(nsi);
+	RC_CHK_ACCESS(nnsi)->need_setns = nsinfo__need_setns(nsi);
+	RC_CHK_ACCESS(nnsi)->in_pidns = nsinfo__in_pidns(nsi);
+	if (nsinfo__mntns_path(nsi)) {
+		RC_CHK_ACCESS(nnsi)->mntns_path = strdup(nsinfo__mntns_path(nsi));
+		if (!RC_CHK_ACCESS(nnsi)->mntns_path) {
+			nsinfo__put(nnsi);
+			return NULL;
 		}
-		refcount_set(&nnsi->refcnt, 1);
 	}
 
 	return nnsi;
 }
 
-void nsinfo__delete(struct nsinfo *nsi)
+static refcount_t *nsinfo__refcnt(struct nsinfo *nsi)
+{
+	return &RC_CHK_ACCESS(nsi)->refcnt;
+}
+
+static void nsinfo__delete(struct nsinfo *nsi)
 {
-	zfree(&nsi->mntns_path);
-	free(nsi);
+	if (nsi) {
+		WARN_ONCE(refcount_read(nsinfo__refcnt(nsi)) != 0, "nsinfo refcnt unbalanced\n");
+		zfree(&RC_CHK_ACCESS(nsi)->mntns_path);
+		RC_CHK_FREE(nsi);
+	}
 }
 
 struct nsinfo *nsinfo__get(struct nsinfo *nsi)
 {
-	if (nsi)
-		refcount_inc(&nsi->refcnt);
-	return nsi;
+	struct nsinfo *result;
+
+	if (RC_CHK_GET(result, nsi))
+		refcount_inc(nsinfo__refcnt(nsi));
+
+	return result;
 }
 
 void nsinfo__put(struct nsinfo *nsi)
 {
-	if (nsi && refcount_dec_and_test(&nsi->refcnt))
+	if (nsi && refcount_dec_and_test(nsinfo__refcnt(nsi)))
 		nsinfo__delete(nsi);
+	else
+		RC_CHK_PUT(nsi);
+}
+
+bool nsinfo__need_setns(const struct nsinfo *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->need_setns;
+}
+
+void nsinfo__clear_need_setns(struct nsinfo *nsi)
+{
+	RC_CHK_ACCESS(nsi)->need_setns = false;
+}
+
+pid_t nsinfo__tgid(const struct nsinfo  *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->tgid;
+}
+
+pid_t nsinfo__nstgid(const struct nsinfo  *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->nstgid;
+}
+
+pid_t nsinfo__pid(const struct nsinfo  *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->pid;
+}
+
+pid_t nsinfo__in_pidns(const struct nsinfo  *nsi)
+{
+	return RC_CHK_ACCESS(nsi)->in_pidns;
 }
 
 void nsinfo__mountns_enter(struct nsinfo *nsi,
@@ -212,7 +285,7 @@ void nsinfo__mountns_enter(struct nsinfo *nsi,
 	nc->oldns = -1;
 	nc->newns = -1;
 
-	if (!nsi || !nsi->need_setns)
+	if (!nsi || !nsinfo__need_setns(nsi))
 		return;
 
 	if (snprintf(curpath, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
@@ -226,7 +299,7 @@ void nsinfo__mountns_enter(struct nsinfo *nsi,
 	if (oldns < 0)
 		goto errout;
 
-	newns = open(nsi->mntns_path, O_RDONLY);
+	newns = open(nsinfo__mntns_path(nsi), O_RDONLY);
 	if (newns < 0)
 		goto errout;
 
@@ -280,3 +353,24 @@ char *nsinfo__realpath(const char *path, struct nsinfo *nsi)
 
 	return rpath;
 }
+
+int nsinfo__stat(const char *filename, struct stat *st, struct nsinfo *nsi)
+{
+	int ret;
+	struct nscookie nsc;
+
+	nsinfo__mountns_enter(nsi, &nsc);
+	ret = stat(filename, st);
+	nsinfo__mountns_exit(&nsc);
+
+	return ret;
+}
+
+bool nsinfo__is_in_root_namespace(void)
+{
+	pid_t tgid = 0, nstgid = 0;
+	bool in_pidns = false;
+
+	nsinfo__get_nspid(&tgid, &nstgid, &in_pidns, "/proc/self/status");
+	return !in_pidns;
+}