linux/tools/perf/util/namespaces.h
Yonatan Goldschmidt 67dec92693 perf inject jit: Add namespaces support
This patch fixes "perf inject --jit" to properly operate on
namespaced/containerized processes:

* jitdump files are generated by the process, thus they should be
  looked up in its mount NS.

* DSOs of injected MMAP events will later be looked up in the process
  mount NS, so write them into its NS.

* PIDs & TIDs from jitdump events need to be translated to the PID as
  seen by "perf record" before written into MMAP events.

For a process in a different PID NS, the TID & PID given in the jitdump
event are actually ignored; I use the TID & PID of the thread which
mmap()ed the jitdump file. This is simplified and won't do for forks of
the initial process, if they continue using the same jitdump file.
Future patches might improve it.

This was tested by recording a NodeJS process running with
"--perf-prof", inside a Docker container, and by recording another
NodeJS process running in the same namespaces as perf itself, to make
sure it's not broken for non-containerized processes.

Signed-off-by: Yonatan Goldschmidt <yonatan.goldschmidt@granulate.io>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung 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/20201105015604.1726943-1-yonatan.goldschmidt@granulate.io
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-02-03 13:10:44 -03:00

75 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
*
* Copyright (C) 2017 Hari Bathini, IBM Corporation
*/
#ifndef __PERF_NAMESPACES_H
#define __PERF_NAMESPACES_H
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/stddef.h>
#include <linux/perf_event.h>
#include <linux/refcount.h>
#include <linux/types.h>
#ifndef HAVE_SETNS_SUPPORT
int setns(int fd, int nstype);
#endif
struct perf_record_namespaces;
struct namespaces {
struct list_head list;
u64 end_time;
struct perf_ns_link_info link_info[];
};
struct namespaces *namespaces__new(struct perf_record_namespaces *event);
void namespaces__free(struct namespaces *namespaces);
struct nsinfo {
pid_t pid;
pid_t tgid;
pid_t nstgid;
bool need_setns;
bool in_pidns;
char *mntns_path;
refcount_t refcnt;
};
struct nscookie {
int oldns;
int newns;
char *oldcwd;
};
int nsinfo__init(struct nsinfo *nsi);
struct nsinfo *nsinfo__new(pid_t pid);
struct nsinfo *nsinfo__copy(struct nsinfo *nsi);
void nsinfo__delete(struct nsinfo *nsi);
struct nsinfo *nsinfo__get(struct nsinfo *nsi);
void nsinfo__put(struct nsinfo *nsi);
void nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc);
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);
static inline void __nsinfo__zput(struct nsinfo **nsip)
{
if (nsip) {
nsinfo__put(*nsip);
*nsip = NULL;
}
}
#define nsinfo__zput(nsi) __nsinfo__zput(&nsi)
const char *perf_ns__name(unsigned int id);
#endif /* __PERF_NAMESPACES_H */