6.1-stable review patch. If anyone has any objections, please let me know.
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From: Arnaldo Carvalho de Melo acme@redhat.com
[ Upstream commit 9c6a585d257f6845731f4e36b45fe42b5c3162f5 ]
When we're processing a perf.data file we will, for every thread in that file do a machine__findnew_thread(machine, pid, tid) that when that pid is seen for the first time will create a 'struct thread' representing it.
That in turn will call nsinfo__new() -> nsinfo__init() and there it will assume we're running live, which is wrong and will need to be addressed in a followup patch.
The nsinfo__new() assumes that if we can't access that thread it has already finished and will ignore the -1 return from nsinfo__init(), just taking notes to avoid trying to enter in that namespace, since it isn't there anymore, a race.
When doing this from 'perf inject', tho, we can fill in parts of that nsinfo from what we get from the PERF_RECORD_MMAP2 (pid, tid) and in the jitdump file name, that has the form of jit-<PID>.dump.
So if the pid in the jitdump file name is not the one in the PERF_RECORD_MMAP2, we can assume that its the pid of the process _inside_ the namespace, and that perf was runing outside that namespace.
This will be done in the following patch.
Reported-by: Francesco Nigro fnigro@redhat.com Reported-by: Ilan Green igreen@redhat.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Clark Williams williams@redhat.com Cc: Ian Rogers irogers@google.com Cc: Ingo Molnar mingo@kernel.org Cc: James Clark james.clark@linaro.org Cc: Jiri Olsa jolsa@kernel.org Cc: Kan Liang kan.liang@linux.intel.com Cc: Namhyung Kim namhyung@kernel.org Cc: Stephane Eranian eranian@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Yonatan Goldschmidt yonatan.goldschmidt@granulate.io Link: https://lore.kernel.org/r/20241206204828.507527-4-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Stable-dep-of: 64a7617efd5a ("perf namespaces: Fixup the nsinfo__in_pidns() return type, its bool") Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/namespaces.c | 5 +++++ tools/perf/util/namespaces.h | 1 + 2 files changed, 6 insertions(+)
diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c index dd536220cdb9e..fe59c2b9cd624 100644 --- a/tools/perf/util/namespaces.c +++ b/tools/perf/util/namespaces.c @@ -242,6 +242,11 @@ pid_t nsinfo__in_pidns(const struct nsinfo *nsi) return nsi->in_pidns; }
+void nsinfo__set_in_pidns(struct nsinfo *nsi) +{ + RC_CHK_ACCESS(nsi)->in_pidns = true; +} + void nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc) { diff --git a/tools/perf/util/namespaces.h b/tools/perf/util/namespaces.h index 567829262c428..62a9145a6ffba 100644 --- a/tools/perf/util/namespaces.h +++ b/tools/perf/util/namespaces.h @@ -58,6 +58,7 @@ pid_t nsinfo__tgid(const struct nsinfo *nsi); pid_t nsinfo__nstgid(const struct nsinfo *nsi); pid_t nsinfo__pid(const struct nsinfo *nsi); pid_t nsinfo__in_pidns(const struct nsinfo *nsi); +void nsinfo__set_in_pidns(struct nsinfo *nsi);
void nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc); void nsinfo__mountns_exit(struct nscookie *nc);