Em Sun, Dec 12, 2021 at 09:47:20PM +0800, Leo Yan escreveu:
> 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.
Thanks, applied.
- Arnaldo
> 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
--
- Arnaldo
