Refactors code for gathering PID infos, it creates the function
nsinfo__get_nspid() to parse process 'status' node in folder '/proc'.
Base on the refactoring, this patch introduces a new helper
nsinfo__is_in_root_namespace(), it returns true when the caller runs in
the root PID namespace.
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
tools/perf/util/namespaces.c | 76 ++++++++++++++++++++++--------------
tools/perf/util/namespaces.h | 2 +
2 files changed, 48 insertions(+), 30 deletions(-)
diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
index 608b20c72a5c..48aa3217300b 100644
--- a/tools/perf/util/namespaces.c
+++ b/tools/perf/util/namespaces.c
@@ -60,17 +60,49 @@ void namespaces__free(struct namespaces *namespaces)
free(namespaces);
}
+static int nsinfo__get_nspid(struct nsinfo *nsi, 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) {
+ 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;
+ }
+ }
+
+ 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;
- 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)
@@ -100,34 +132,9 @@ int nsinfo__init(struct nsinfo *nsi)
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;
+ rv = nsinfo__get_nspid(nsi, spath);
out:
- if (f != NULL)
- (void) fclose(f);
- free(statln);
free(newns);
return rv;
}
@@ -299,3 +306,12 @@ int nsinfo__stat(const char *filename, struct stat *st, struct nsinfo *nsi)
return ret;
}
+
+bool nsinfo__is_in_root_namespace(void)
+{
+ struct nsinfo nsi;
+
+ memset(&nsi, 0x0, sizeof(nsi));
+ nsinfo__get_nspid(&nsi, "/proc/self/status");
+ return !nsi.in_pidns;
+}
diff --git a/tools/perf/util/namespaces.h b/tools/perf/util/namespaces.h
index ad9775db7b9c..9ceea9643507 100644
--- a/tools/perf/util/namespaces.h
+++ b/tools/perf/util/namespaces.h
@@ -59,6 +59,8 @@ void nsinfo__mountns_exit(struct nscookie *nc);
char *nsinfo__realpath(const char *path, struct nsinfo *nsi);
int nsinfo__stat(const char *filename, struct stat *st, struct nsinfo *nsi);
+bool nsinfo__is_in_root_namespace(void);
+
static inline void __nsinfo__zput(struct nsinfo **nsip)
{
if (nsip) {
--
2.25.1
