diff options
Diffstat (limited to '')
-rw-r--r-- | tools/perf/util/namespaces.c | 226 |
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; +} |