// SPDX-License-Identifier: GPL-2.0-only/* * * Copyright (C) 2017 Hari Bathini, IBM Corporation */ #include "namespaces.h"#include "event.h"#include "get_current_dir_name.h"#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <limits.h>#include <sched.h>#include <stdlib.h>#include <stdio.h>#include <string.h>#include <unistd.h>#include <asm/bug.h>#include <linux/kernel.h>#include <linux/zalloc.h> static const char *perf_ns__names[] = {	[NET_NS_INDEX]		= "net",	[UTS_NS_INDEX]		= "uts",	[IPC_NS_INDEX]		= "ipc",	[PID_NS_INDEX]		= "pid",	[USER_NS_INDEX]		= "user",	[MNT_NS_INDEX]		= "mnt",	[CGROUP_NS_INDEX]	= "cgroup",}; const char *perf_ns__name(unsigned int id){	if (id >= ARRAY_SIZE(perf_ns__names))		return "UNKNOWN";	return perf_ns__names[id];} struct namespaces *namespaces__new(struct perf_record_namespaces *event){	struct namespaces *namespaces;	u64 link_info_size = ((event ? event->nr_namespaces : NR_NAMESPACES) *			      sizeof(struct perf_ns_link_info)); 	namespaces = zalloc(sizeof(struct namespaces) + link_info_size);	if (!namespaces)		return NULL; 	namespaces->end_time = -1; 	if (event)		memcpy(namespaces->link_info, event->link_info, link_info_size); 	return namespaces;} void namespaces__free(struct namespaces *namespaces){	free(namespaces);} int nsinfo__init(struct nsinfo *nsi){	char oldns[PATH_MAX];	char spath[PATH_MAX];	char *newns = NULL;	char *statln = NULL;	char *nspid;	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)		return rv; 	if (stat(oldns, &old_stat) < 0)		goto out; 	if (stat(newns, &new_stat) < 0)		goto out; 	/* Check if the mount namespaces differ, if so then indicate that we	 * 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;		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)		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) {			nspid = strrchr(statln, '\t');			nsi->nstgid = (pid_t)strtol(nspid, NULL, 10);			/* If innermost tgid is not the first, process is in a different			 * PID namespace.			 */			nsi->in_pidns = (statln + sizeof("NStgid:") - 1) != nspid;			break;		}	}	rv = 0; out:	if (f != NULL)		(void) fclose(f);	free(statln);	free(newns);	return rv;} struct nsinfo *nsinfo__new(pid_t pid){	struct nsinfo *nsi; 	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;		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)			nsi->need_setns = false; 		refcount_set(&nsi->refcnt, 1);	} 	return nsi;} struct nsinfo *nsinfo__copy(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;		nnsi->in_pidns = nsi->in_pidns;		if (nsi->mntns_path) {			nnsi->mntns_path = strdup(nsi->mntns_path);			if (!nnsi->mntns_path) {				free(nnsi);				return NULL;			}		}		refcount_set(&nnsi->refcnt, 1);	} 	return nnsi;} void nsinfo__delete(struct nsinfo *nsi){	zfree(&nsi->mntns_path);	free(nsi);} struct nsinfo *nsinfo__get(struct nsinfo *nsi){	if (nsi)		refcount_inc(&nsi->refcnt);	return nsi;} void nsinfo__put(struct nsinfo *nsi){	if (nsi && refcount_dec_and_test(&nsi->refcnt))		nsinfo__delete(nsi);} void nsinfo__mountns_enter(struct nsinfo *nsi,				  struct nscookie *nc){	char curpath[PATH_MAX];	int oldns = -1;	int newns = -1;	char *oldcwd = NULL; 	if (nc == NULL)		return; 	nc->oldns = -1;	nc->newns = -1; 	if (!nsi || !nsi->need_setns)		return; 	if (snprintf(curpath, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)		return; 	oldcwd = get_current_dir_name();	if (!oldcwd)		return; 	oldns = open(curpath, O_RDONLY);	if (oldns < 0)		goto errout; 	newns = open(nsi->mntns_path, O_RDONLY);	if (newns < 0)		goto errout; 	if (setns(newns, CLONE_NEWNS) < 0)		goto errout; 	nc->oldcwd = oldcwd;	nc->oldns = oldns;	nc->newns = newns;	return; errout:	free(oldcwd);	if (oldns > -1)		close(oldns);	if (newns > -1)		close(newns);} void nsinfo__mountns_exit(struct nscookie *nc){	if (nc == NULL || nc->oldns == -1 || nc->newns == -1 || !nc->oldcwd)		return; 	setns(nc->oldns, CLONE_NEWNS); 	if (nc->oldcwd) {		WARN_ON_ONCE(chdir(nc->oldcwd));		zfree(&nc->oldcwd);	} 	if (nc->oldns > -1) {		close(nc->oldns);		nc->oldns = -1;	} 	if (nc->newns > -1) {		close(nc->newns);		nc->newns = -1;	}} char *nsinfo__realpath(const char *path, struct nsinfo *nsi){	char *rpath;	struct nscookie nsc; 	nsinfo__mountns_enter(nsi, &nsc);	rpath = realpath(path, NULL);	nsinfo__mountns_exit(&nsc); 	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;}