forked from luck/tmp_suning_uos_patched
b01c1f69c8
When reporting on 'record' server we try to retrieve/use the mnt
namespace of the profiled tasks. We use following API with cookie to
hold the return namespace, roughly:
nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc)
setns(newns, 0);
...
new ns related open..
...
nsinfo__mountns_exit(struct nscookie *nc)
setns(nc->oldns)
Once finished we setns to old namespace, which also sets the current
working directory (cwd) to "/", trashing the cwd we had.
This is mostly fine, because we use absolute paths almost everywhere,
but it screws up 'perf diff':
# perf diff
failed to open perf.data: No such file or directory (try 'perf record' first)
...
Adding the current working directory to be part of the cookie and
restoring it in the nsinfo__mountns_exit call.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 843ff37bb5 ("perf symbols: Find symbols in different mount namespace")
Link: http://lkml.kernel.org/r/20181101170001.30019-1-jolsa@kernel.org
[ No need to check for NULL args for free(), use zfree() for struct members ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* Copyright (C) 2017 Hari Bathini, IBM Corporation
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*/
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#ifndef __PERF_NAMESPACES_H
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#define __PERF_NAMESPACES_H
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#include <sys/types.h>
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#include <linux/stddef.h>
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#include <linux/perf_event.h>
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#include <linux/refcount.h>
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#include <linux/types.h>
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struct namespaces_event;
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struct namespaces {
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struct list_head list;
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u64 end_time;
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struct perf_ns_link_info link_info[];
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};
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struct namespaces *namespaces__new(struct namespaces_event *event);
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void namespaces__free(struct namespaces *namespaces);
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struct nsinfo {
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pid_t pid;
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pid_t tgid;
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pid_t nstgid;
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bool need_setns;
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char *mntns_path;
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refcount_t refcnt;
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};
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struct nscookie {
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int oldns;
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int newns;
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char *oldcwd;
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};
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int nsinfo__init(struct nsinfo *nsi);
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struct nsinfo *nsinfo__new(pid_t pid);
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struct nsinfo *nsinfo__copy(struct nsinfo *nsi);
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void nsinfo__delete(struct nsinfo *nsi);
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struct nsinfo *nsinfo__get(struct nsinfo *nsi);
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void nsinfo__put(struct nsinfo *nsi);
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void nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc);
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void nsinfo__mountns_exit(struct nscookie *nc);
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char *nsinfo__realpath(const char *path, struct nsinfo *nsi);
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static inline void __nsinfo__zput(struct nsinfo **nsip)
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{
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if (nsip) {
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nsinfo__put(*nsip);
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*nsip = NULL;
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}
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}
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#define nsinfo__zput(nsi) __nsinfo__zput(&nsi)
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#endif /* __PERF_NAMESPACES_H */
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