From 3b5692864da3a8dec95d8c757147f436d19f8ff7 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 6 Mar 2018 15:53:22 -0300 Subject: [PATCH] perf cgroup: Make the cgroup name be const char * The usual thing is for a constructor to allocate space for its members, not to require that the caller pass a pre-allocated 'name' and then, at its destructor, to free something not allocated by it. Fix it by making cgroup__new() to receive a const char pointer, then allocate cgroup->name that then can continue to be freed at cgroup__delete(), balancing the alloc/free operations inside the cgroup struct methods. This eases calling evlist__findnew_cgroup() from the custom 'perf trace' cgroup parser, that will only call parse_cgroups() when the '-G cgroup' is passed on the command line after '-e event' entries, when it'll behave just like 'perf stat' and 'perf record', i.e. the previous parse_cgroup() users that mandate that -G only can come after a -e. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-4leugnuyqi10t98990o3xi1t@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/cgroup.c | 24 ++++++++++++++---------- tools/perf/util/cgroup.h | 2 +- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index d8cd0e601c56..78408f5c4bad 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -71,7 +71,7 @@ cgroupfs_find_mountpoint(char *buf, size_t maxlen) return -1; } -static int open_cgroup(char *name) +static int open_cgroup(const char *name) { char path[PATH_MAX + 1]; char mnt[PATH_MAX + 1]; @@ -90,7 +90,7 @@ static int open_cgroup(char *name) return fd; } -static struct cgroup *evlist__find_cgroup(struct perf_evlist *evlist, char *str) +static struct cgroup *evlist__find_cgroup(struct perf_evlist *evlist, const char *str) { struct perf_evsel *counter; struct cgroup *cgrp = NULL; @@ -109,33 +109,38 @@ static struct cgroup *evlist__find_cgroup(struct perf_evlist *evlist, char *str) return cgrp; } -static struct cgroup *cgroup__new(char *name) +static struct cgroup *cgroup__new(const char *name) { struct cgroup *cgroup = zalloc(sizeof(*cgroup)); if (cgroup != NULL) { - cgroup->name = name; refcount_set(&cgroup->refcnt, 1); + cgroup->name = strdup(name); + if (!cgroup->name) + goto out_err; cgroup->fd = open_cgroup(name); if (cgroup->fd == -1) - goto out_err; + goto out_free_name; } return cgroup; + +out_free_name: + free(cgroup->name); out_err: free(cgroup); return NULL; } -struct cgroup *evlist__findnew_cgroup(struct perf_evlist *evlist, char *name) +struct cgroup *evlist__findnew_cgroup(struct perf_evlist *evlist, const char *name) { struct cgroup *cgroup = evlist__find_cgroup(evlist, name); return cgroup ?: cgroup__new(name); } -static int add_cgroup(struct perf_evlist *evlist, char *str) +static int add_cgroup(struct perf_evlist *evlist, const char *str) { struct perf_evsel *counter; struct cgroup *cgrp = evlist__findnew_cgroup(evlist, str); @@ -222,10 +227,9 @@ int parse_cgroups(const struct option *opt, const char *str, if (!s) return -1; ret = add_cgroup(evlist, s); - if (ret) { - free(s); + free(s); + if (ret) return -1; - } } /* nr_cgroups is increased een for empty cgroups */ nr_cgroups++; diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h index b213f5e9a3ed..f033a80c1b14 100644 --- a/tools/perf/util/cgroup.h +++ b/tools/perf/util/cgroup.h @@ -20,7 +20,7 @@ void cgroup__put(struct cgroup *cgroup); struct perf_evlist; -struct cgroup *evlist__findnew_cgroup(struct perf_evlist *evlist, char *name); +struct cgroup *evlist__findnew_cgroup(struct perf_evlist *evlist, const char *name); void evlist__set_default_cgroup(struct perf_evlist *evlist, struct cgroup *cgroup); -- 2.30.2