Commit 2b51c71b authored by Yonatan Goldschmidt's avatar Yonatan Goldschmidt Committed by Arnaldo Carvalho de Melo
Browse files

perf namespaces: Add 'in_pidns' to nsinfo struct 



Provides an accurate mean to determine if the owner thread is in a
different PID namespace.

Signed-off-by: default avatarYonatan Goldschmidt <yonatan.goldschmidt@granulate.io>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20201105015418.1725218-1-yonatan.goldschmidt@granulate.io


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 473f742e

tools/perf/util/namespaces.c

+9 −2
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ int nsinfo__init(struct nsinfo *nsi) 
	char spath[PATH_MAX];

	char *newns = NULL;

	char *statln = NULL;

	char *nspid;

	struct stat old_stat;

	struct stat new_stat;

	FILE *f = NULL;
@@ -112,8 +113,12 @@ int nsinfo__init(struct nsinfo *nsi) 
		}



		if (strstr(statln, "NStgid:") != NULL) {

			nsi->nstgid = (pid_t)strtol(strrchr(statln, '\t'),

						     NULL, 10);

			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;

		}

	}
@@ -140,6 +145,7 @@ struct nsinfo *nsinfo__new(pid_t 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.
@@ -166,6 +172,7 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi) 
		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) {

tools/perf/util/namespaces.h

+1 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ struct nsinfo { 
	pid_t			tgid;

	pid_t			nstgid;

	bool			need_setns;

	bool			in_pidns;

	char			*mntns_path;

	refcount_t		refcnt;

};