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

Arnaldo Carvalho de Melo
2022-02-11T17:31:54Z

Em Fri, Feb 11, 2022 at 02:34:06AM -0800, Ian Rogers escreveu:
> Having functions to access nsinfo reduces the places where reference
> counting checking needs to be added.

Looks sensible, applied.

- Arnaldo

> 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

--

- Arnaldo