[PATCH v3 13/22] perf namespaces: Add functions to access nsinfo

Ian Rogers
2022-02-11T10:35:27Z

Having functions to access nsinfo reduces the places where reference
counting checking needs to be added.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-inject.c | 2 +-
tools/perf/builtin-probe.c | 2 +-
tools/perf/util/build-id.c | 4 +--
tools/perf/util/jitdump.c | 10 ++++----
tools/perf/util/map.c | 4 +--
tools/perf/util/namespaces.c | 50 ++++++++++++++++++++++++++++--------
tools/perf/util/namespaces.h | 10 ++++++--
tools/perf/util/symbol.c | 8 +++---
8 files changed, 63 insertions(+), 27 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index bede332bf0e2..f7917c390e96 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -354,7 +354,7 @@ static struct dso *findnew_dso(int pid, int tid, const char *filename,
nnsi = nsinfo__copy(nsi);
if (nnsi) {
nsinfo__put(nsi);
- nnsi->need_setns = false;
+ nsinfo__clear_need_setns(nnsi);
nsi = nnsi;
}
dso = machine__findnew_vdso(machine, thread);
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index c31627af75d4..f62298f5db3b 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -217,7 +217,7 @@ static int opt_set_target_ns(const struct option *opt __maybe_unused,
return ret;
}
nsip = nsinfo__new(ns_pid);
- if (nsip && nsip->need_setns)
+ if (nsip && nsinfo__need_setns(nsip))
params.nsi = nsinfo__get(nsip);
nsinfo__put(nsip);

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index e32e8f2ff3bd..7a5821c87f94 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -706,7 +706,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
if (is_kallsyms) {
if (copyfile("/proc/kallsyms", filename))
goto out_free;
- } else if (nsi && nsi->need_setns) {
+ } else if (nsi && nsinfo__need_setns(nsi)) {
if (copyfile_ns(name, filename, nsi))
goto out_free;
} else if (link(realname, filename) && errno != EEXIST &&
@@ -730,7 +730,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
goto out_free;
}
if (access(filename, F_OK)) {
- if (nsi && nsi->need_setns) {
+ if (nsi && nsinfo__need_setns(nsi)) {
if (copyfile_ns(debugfile, filename,
nsi))
goto out_free;
diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
index 917a9c707371..a23255773c60 100644
--- a/tools/perf/util/jitdump.c
+++ b/tools/perf/util/jitdump.c
@@ -382,15 +382,15 @@ jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)

static pid_t jr_entry_pid(struct jit_buf_desc *jd, union jr_entry *jr)
{
- if (jd->nsi && jd->nsi->in_pidns)
- return jd->nsi->tgid;
+ if (jd->nsi && nsinfo__in_pidns(jd->nsi))
+ return nsinfo__tgid(jd->nsi);
return jr->load.pid;
}

static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
{
- if (jd->nsi && jd->nsi->in_pidns)
- return jd->nsi->pid;
+ if (jd->nsi && nsinfo__in_pidns(jd->nsi))
+ return nsinfo__pid(jd->nsi);
return jr->load.tid;
}

@@ -779,7 +779,7 @@ jit_detect(char *mmap_name, pid_t pid, struct nsinfo *nsi)
* pid does not match mmap pid
* pid==0 in system-wide mode (synthesized)
*/
- if (pid && pid2 != nsi->nstgid)
+ if (pid && pid2 != nsinfo__nstgid(nsi))
return -1;
/*
* validate suffix
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index dfa5f6b7381f..166c84c829f6 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -139,7 +139,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,

if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
snprintf(newfilename, sizeof(newfilename),
- "/tmp/perf-%d.map", nsi->pid);
+ "/tmp/perf-%d.map", nsinfo__pid(nsi));
filename = newfilename;
}

@@ -156,7 +156,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
nnsi = nsinfo__copy(nsi);
if (nnsi) {
nsinfo__put(nsi);
- nnsi->need_setns = false;
+ nsinfo__clear_need_setns(nnsi);
nsi = nnsi;
}
pgoff = 0;
diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
index 48aa3217300b..dd536220cdb9 100644
--- a/tools/perf/util/namespaces.c
+++ b/tools/perf/util/namespaces.c
@@ -76,7 +76,7 @@ static int nsinfo__get_nspid(struct nsinfo *nsi, const char *path)
if (strstr(statln, "Tgid:") != NULL) {
nsi->tgid = (pid_t)strtol(strrchr(statln, '\t'),
NULL, 10);
- nsi->nstgid = nsi->tgid;
+ nsi->nstgid = nsinfo__tgid(nsi);
}

if (strstr(statln, "NStgid:") != NULL) {
@@ -108,7 +108,7 @@ int nsinfo__init(struct nsinfo *nsi)
if (snprintf(oldns, PATH_MAX, "/proc/self/ns/mnt") >= PATH_MAX)
return rv;

- if (asprintf(&newns, "/proc/%d/ns/mnt", nsi->pid) == -1)
+ if (asprintf(&newns, "/proc/%d/ns/mnt", nsinfo__pid(nsi)) == -1)
return rv;

if (stat(oldns, &old_stat) < 0)
@@ -129,7 +129,7 @@ int nsinfo__init(struct nsinfo *nsi)
/* If we're dealing with a process that is in a different PID namespace,
* attempt to work out the innermost tgid for the process.
*/
- if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsi->pid) >= PATH_MAX)
+ if (snprintf(spath, PATH_MAX, "/proc/%d/status", nsinfo__pid(nsi)) >= PATH_MAX)
goto out;

rv = nsinfo__get_nspid(nsi, spath);
@@ -166,7 +166,7 @@ struct nsinfo *nsinfo__new(pid_t pid)
return nsi;
}

-struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
+struct nsinfo *nsinfo__copy(const struct nsinfo *nsi)
{
struct nsinfo *nnsi;

@@ -175,11 +175,11 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)

nnsi = calloc(1, sizeof(*nnsi));
if (nnsi != NULL) {
- nnsi->pid = nsi->pid;
- nnsi->tgid = nsi->tgid;
- nnsi->nstgid = nsi->nstgid;
- nnsi->need_setns = nsi->need_setns;
- nnsi->in_pidns = nsi->in_pidns;
+ nnsi->pid = nsinfo__pid(nsi);
+ nnsi->tgid = nsinfo__tgid(nsi);
+ nnsi->nstgid = nsinfo__nstgid(nsi);
+ nnsi->need_setns = nsinfo__need_setns(nsi);
+ nnsi->in_pidns = nsinfo__in_pidns(nsi);
if (nsi->mntns_path) {
nnsi->mntns_path = strdup(nsi->mntns_path);
if (!nnsi->mntns_path) {
@@ -193,7 +193,7 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
return nnsi;
}

-void nsinfo__delete(struct nsinfo *nsi)
+static void nsinfo__delete(struct nsinfo *nsi)
{
zfree(&nsi->mntns_path);
free(nsi);
@@ -212,6 +212,36 @@ void nsinfo__put(struct nsinfo *nsi)
nsinfo__delete(nsi);
}

+bool nsinfo__need_setns(const struct nsinfo *nsi)
+{
+ return nsi->need_setns;
+}
+
+void nsinfo__clear_need_setns(struct nsinfo *nsi)
+{
+ nsi->need_setns = false;
+}
+
+pid_t nsinfo__tgid(const struct nsinfo *nsi)
+{
+ return nsi->tgid;
+}
+
+pid_t nsinfo__nstgid(const struct nsinfo *nsi)
+{
+ return nsi->nstgid;
+}
+
+pid_t nsinfo__pid(const struct nsinfo *nsi)
+{
+ return nsi->pid;
+}
+
+pid_t nsinfo__in_pidns(const struct nsinfo *nsi)
+{
+ return nsi->in_pidns;
+}
+
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 9ceea9643507..567829262c42 100644
--- a/tools/perf/util/namespaces.h
+++ b/tools/perf/util/namespaces.h
@@ -47,12 +47,18 @@ struct nscookie {

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__copy(const struct nsinfo *nsi);

struct nsinfo *nsinfo__get(struct nsinfo *nsi);
void nsinfo__put(struct nsinfo *nsi);

+bool nsinfo__need_setns(const struct nsinfo *nsi);
+void nsinfo__clear_need_setns(struct nsinfo *nsi);
+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__mountns_enter(struct nsinfo *nsi, struct nscookie *nc);
void nsinfo__mountns_exit(struct nscookie *nc);

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 266c65bb8bbb..e8045b1c8700 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1784,8 +1784,8 @@ static int dso__find_perf_map(char *filebuf, size_t bufsz,

nsi = *nsip;

- if (nsi->need_setns) {
- snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
+ if (nsinfo__need_setns(nsi)) {
+ snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
nsinfo__mountns_enter(nsi, &nsc);
rc = access(filebuf, R_OK);
nsinfo__mountns_exit(&nsc);
@@ -1797,8 +1797,8 @@ static int dso__find_perf_map(char *filebuf, size_t bufsz,
if (nnsi) {
nsinfo__put(nsi);

- nnsi->need_setns = false;
- snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
+ nsinfo__clear_need_setns(nnsi);
+ snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
*nsip = nnsi;
rc = 0;
}
--
2.35.1.265.g69c8d7142f-goog