perf tools: Introduce zfree

For the frequent idiom of:

   free(ptr);
   ptr = NULL;

Make it expect a pointer to the pointer being freed, so that it becomes
clear at first sight that the variable being freed is being modified.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-pfw02ezuab37kha18wlut7ir@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

22 files changed, 56 insertions, 103 deletions

diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
index aacef07ebf31..42faf369211c 100644
--- a/tools/perf/arch/common.c
+++ b/tools/perf/arch/common.c
@@ -154,8 +154,7 @@ static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
                 }
                 if (lookup_path(buf))
                         goto out;
-                free(buf);
-                buf = NULL;
+                zfree(&buf);
         }
 
         if (!strcmp(arch, "arm"))
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 4136f9970fd5..ab65057a0317 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -180,8 +180,7 @@ find_next:
                          * symbol, free he->ms.sym->src to signal we already
                          * processed this symbol.
                          */
-                        free(notes->src);
-                        notes->src = NULL;
+                        zfree(&notes->src);
                 }
         }
 }
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index dab98b50c9fe..106a5e5b7842 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -185,8 +185,7 @@ static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)
 
 static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
 {
-        free(evsel->priv);
-        evsel->priv = NULL;
+        zfree(&evsel->priv);
 }
 
 static int perf_evsel__alloc_prev_raw_counts(struct perf_evsel *evsel)
@@ -208,8 +207,7 @@ static int perf_evsel__alloc_prev_raw_counts(struct perf_evsel *evsel)
 
 static void perf_evsel__free_prev_raw_counts(struct perf_evsel *evsel)
 {
-        free(evsel->prev_raw_counts);
-        evsel->prev_raw_counts = NULL;
+        zfree(&evsel->prev_raw_counts);
 }
 
 static void perf_evlist__free_stats(struct perf_evlist *evlist)
diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 20d4212fa337..652af0b66a62 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -488,8 +488,7 @@ static const char *cat_backtrace(union perf_event *event,
                                  * It seems the callchain is corrupted.
                                  * Discard all.
                                  */
-                                free(p);
-                                p = NULL;
+                                zfree(&p);
                                 goto exit;
                         }
                         continue;
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index f64b5b0aa8b1..c5b4bc51175c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -146,8 +146,7 @@ static int perf_evsel__init_tp_ptr_field(struct perf_evsel *evsel,
 
 static void perf_evsel__delete_priv(struct perf_evsel *evsel)
 {
-        free(evsel->priv);
-        evsel->priv = NULL;
+        zfree(&evsel->priv);
         perf_evsel__delete(evsel);
 }
 
@@ -165,8 +164,7 @@ static int perf_evsel__init_syscall_tp(struct perf_evsel *evsel, void *handler)
         return -ENOMEM;
 
 out_delete:
-        free(evsel->priv);
-        evsel->priv = NULL;
+        zfree(&evsel->priv);
         return -ENOENT;
 }
 
@@ -1278,10 +1276,8 @@ static size_t syscall_arg__scnprintf_close_fd(char *bf, size_t size,
         size_t printed = syscall_arg__scnprintf_fd(bf, size, arg);
         struct thread_trace *ttrace = arg->thread->priv;
 
-        if (ttrace && fd >= 0 && fd <= ttrace->paths.max) {
-                free(ttrace->paths.table[fd]);
-                ttrace->paths.table[fd] = NULL;
-        }
+        if (ttrace && fd >= 0 && fd <= ttrace->paths.max)
+                zfree(&ttrace->paths.table[fd]);
 
         return printed;
 }
diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index 94223d404f43..d11541d4d7d7 100644
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -256,8 +256,7 @@ int ui_browser__show(struct ui_browser *browser, const char *title,
         __ui_browser__show_title(browser, title);
 
         browser->title = title;
-        free(browser->helpline);
-        browser->helpline = NULL;
+        zfree(&browser->helpline);
 
         va_start(ap, helpline);
         err = vasprintf(&browser->helpline, helpline, ap);
@@ -272,8 +271,7 @@ void ui_browser__hide(struct ui_browser *browser)
 {
         pthread_mutex_lock(&ui__lock);
         ui_helpline__pop();
-        free(browser->helpline);
-        browser->helpline = NULL;
+        zfree(&browser->helpline);
         pthread_mutex_unlock(&ui__lock);
 }
 
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 0d9dd99507ee..022d1731b801 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1267,10 +1267,8 @@ static inline void free_popup_options(char **options, int n)
 {
         int i;
 
-        for (i = 0; i < n; ++i) {
-                free(options[i]);
-                options[i] = NULL;
-        }
+        for (i = 0; i < n; ++i)
+                zfree(&options[i]);
 }
 
 /* Check whether the browser is for 'top' or 'report' */
diff --git a/tools/perf/ui/gtk/util.c b/tools/perf/ui/gtk/util.c
index 696c1fbe4248..52e7fc48af9f 100644
--- a/tools/perf/ui/gtk/util.c
+++ b/tools/perf/ui/gtk/util.c
@@ -23,8 +23,7 @@ int perf_gtk__deactivate_context(struct perf_gtk_context **ctx)
         if (!perf_gtk__is_active_context(*ctx))
                 return -1;
 
-        free(*ctx);
-        *ctx = NULL;
+        zfree(ctx);
         return 0;
 }
 
diff --git a/tools/perf/util/alias.c b/tools/perf/util/alias.c
index e6d134773d0a..c0b43ee40d95 100644
--- a/tools/perf/util/alias.c
+++ b/tools/perf/util/alias.c
@@ -55,8 +55,7 @@ int split_cmdline(char *cmdline, const char ***argv)
                                 src++;
                                 c = cmdline[src];
                                 if (!c) {
-                                        free(*argv);
-                                        *argv = NULL;
+                                        zfree(argv);
                                         return error("cmdline ends with \\");
                                 }
                         }
@@ -68,8 +67,7 @@ int split_cmdline(char *cmdline, const char ***argv)
         cmdline[dst] = 0;
 
         if (quoted) {
-                free(*argv);
-                *argv = NULL;
+                zfree(argv);
                 return error("unclosed quote");
         }
 
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 27ab7b59dbf4..a78721d14694 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -185,8 +185,7 @@ static int lock__parse(struct ins_operands *ops)
         return 0;
 
 out_free_ops:
-        free(ops->locked.ops);
-        ops->locked.ops = NULL;
+        zfree(&ops->locked.ops);
         return 0;
 }
 
@@ -256,8 +255,7 @@ static int mov__parse(struct ins_operands *ops)
         return 0;
 
 out_free_source:
-        free(ops->source.raw);
-        ops->source.raw = NULL;
+        zfree(&ops->source.raw);
         return -1;
 }
 
@@ -560,8 +558,7 @@ static int disasm_line__parse(char *line, char **namep, char **rawp)
         return 0;
 
 out_free_name:
-        free(*namep);
-        *namep = NULL;
+        zfree(namep);
         return -1;
 }
 
@@ -1113,8 +1110,7 @@ static void symbol__free_source_line(struct symbol *sym, int len)
                 src_line = (void *)src_line + sizeof_src_line;
         }
 
-        free(notes->src->lines);
-        notes->src->lines = NULL;
+        zfree(&notes->src->lines);
 }
 
 /* Get the filename:line for the colored entries */
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 4ddeecb9ff85..4045d086d9d9 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -497,21 +497,18 @@ void dso__delete(struct dso *dso)
                 symbols__delete(&dso->symbols[i]);
 
         if (dso->short_name_allocated) {
-                free((char *)dso->short_name);
-                dso->short_name           = NULL;
+                zfree((char **)&dso->short_name);
                 dso->short_name_allocated = false;
         }
 
         if (dso->long_name_allocated) {
-                free((char *)dso->long_name);
-                dso->long_name           = NULL;
+                zfree((char **)&dso->long_name);
                 dso->long_name_allocated = false;
         }
 
         dso_cache__free(&dso->cache);
         dso__free_a2l(dso);
-        free(dso->symsrc_filename);
-        dso->symsrc_filename = NULL;
+        zfree(&dso->symsrc_filename);
         free(dso);
 }
 
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index da3182914984..b08a7ecdcea1 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -101,10 +101,8 @@ static void perf_evlist__purge(struct perf_evlist *evlist)
 
 void perf_evlist__exit(struct perf_evlist *evlist)
 {
-        free(evlist->mmap);
-        free(evlist->pollfd);
-        evlist->mmap = NULL;
-        evlist->pollfd = NULL;
+        zfree(&evlist->mmap);
+        zfree(&evlist->pollfd);
 }
 
 void perf_evlist__delete(struct perf_evlist *evlist)
@@ -587,8 +585,7 @@ void perf_evlist__munmap(struct perf_evlist *evlist)
         for (i = 0; i < evlist->nr_mmaps; i++)
                 __perf_evlist__munmap(evlist, i);
 
-        free(evlist->mmap);
-        evlist->mmap = NULL;
+        zfree(&evlist->mmap);
 }
 
 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6874e0485693..93b6031d5459 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -750,8 +750,7 @@ void perf_evsel__free_id(struct perf_evsel *evsel)
 {
         xyarray__delete(evsel->sample_id);
         evsel->sample_id = NULL;
-        free(evsel->id);
-        evsel->id = NULL;
+        zfree(&evsel->id);
 }
 
 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
@@ -1960,8 +1959,7 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
                 evsel->attr.type   = PERF_TYPE_SOFTWARE;
                 evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
 
-                free(evsel->name);
-                evsel->name = NULL;
+                zfree(&evsel->name);
                 return true;
         }
 
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 10730b0af804..20f3a9c97bd8 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1324,8 +1324,7 @@ read_event_desc(struct perf_header *ph, int fd)
                 }
         }
 out:
-        if (buf)
-                free(buf);
+        free(buf);
         return events;
 error:
         if (events)
diff --git a/tools/perf/util/help.c b/tools/perf/util/help.c
index 8b1f6e891b8a..7b68978e50d2 100644
--- a/tools/perf/util/help.c
+++ b/tools/perf/util/help.c
@@ -263,9 +263,8 @@ static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 
         for (i = 0; i < old->cnt; i++)
                 cmds->names[cmds->cnt++] = old->names[i];
-        free(old->names);
+        zfree(&old->names);
         old->cnt = 0;
-        old->names = NULL;
 }
 
 const char *help_unknown_cmd(const char *cmd)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index c78cc84f433e..a98538dc465a 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -102,8 +102,7 @@ void machine__exit(struct machine *machine)
         map_groups__exit(&machine->kmaps);
         dsos__delete(&machine->user_dsos);
         dsos__delete(&machine->kernel_dsos);
-        free(machine->root_dir);
-        machine->root_dir = NULL;
+        zfree(&machine->root_dir);
 }
 
 void machine__delete(struct machine *machine)
@@ -562,11 +561,10 @@ void machine__destroy_kernel_maps(struct machine *machine)
                          * on one of them.
                          */
                         if (type == MAP__FUNCTION) {
-                                free((char *)kmap->ref_reloc_sym->name);
-                                kmap->ref_reloc_sym->name = NULL;
-                                free(kmap->ref_reloc_sym);
-                        }
-                        kmap->ref_reloc_sym = NULL;
+                                zfree((char **)&kmap->ref_reloc_sym->name);
+                                zfree(&kmap->ref_reloc_sym);
+                        } else
+                                kmap->ref_reloc_sym = NULL;
                 }
 
                 map__delete(machine->vmlinux_maps[type]);
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 095a98ec7444..4d3cd1a0278a 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -506,15 +506,13 @@ static int get_real_path(const char *raw_path, const char *comp_dir,
                 case EFAULT:
                         raw_path = strchr(++raw_path, '/');
                         if (!raw_path) {
-                                free(*new_path);
-                                *new_path = NULL;
+                                zfree(new_path);
                                 return -ENOENT;
                         }
                         continue;
 
                 default:
-                        free(*new_path);
-                        *new_path = NULL;
+                        zfree(new_path);
                         return -errno;
                 }
         }
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 8c087359b7ce..6d8796e38d7f 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -226,10 +226,8 @@ struct debuginfo *debuginfo__new(const char *path)
         if (!dbg)
                 return NULL;
 
-        if (debuginfo__init_offline_dwarf(dbg, path) < 0) {
-                free(dbg);
-                dbg = NULL;
-        }
+        if (debuginfo__init_offline_dwarf(dbg, path) < 0)
+                zfree(&dbg);
 
         return dbg;
 }
@@ -241,10 +239,8 @@ struct debuginfo *debuginfo__new_online_kernel(unsigned long addr)
         if (!dbg)
                 return NULL;
 
-        if (debuginfo__init_online_kernel_dwarf(dbg, (Dwarf_Addr)addr) < 0) {
-                free(dbg);
-                dbg = NULL;
-        }
+        if (debuginfo__init_online_kernel_dwarf(dbg, (Dwarf_Addr)addr) < 0)
+                zfree(&dbg);
 
         return dbg;
 }
@@ -1302,8 +1298,7 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
 
         ret = debuginfo__find_probes(dbg, &tf.pf);
         if (ret < 0) {
-                free(*tevs);
-                *tevs = NULL;
+                zfree(tevs);
                 return ret;
         }
 
@@ -1417,8 +1412,7 @@ int debuginfo__find_available_vars_at(struct debuginfo *dbg,
                         free(af.vls[af.nvls].point.symbol);
                         strlist__delete(af.vls[af.nvls].vars);
                 }
-                free(af.vls);
-                *vls = NULL;
+                zfree(vls);
                 return ret;
         }
 
@@ -1522,8 +1516,7 @@ post:
         if (fname) {
                 ppt->file = strdup(fname);
                 if (ppt->file == NULL) {
-                        free(ppt->function);
-                        ppt->function = NULL;
+                        zfree(&ppt->function);
                         ret = -ENOMEM;
                         goto end;
                 }
@@ -1577,8 +1570,7 @@ static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
                 else
                         ret = 0;        /* Lines are not found */
         else {
-                free(lf->lr->path);
-                lf->lr->path = NULL;
+                zfree(&lf->lr->path);
         }
         return ret;
 }
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 923d00040bbf..fd9e1a4fad16 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1621,13 +1621,10 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
 
 static void vmlinux_path__exit(void)
 {
-        while (--vmlinux_path__nr_entries >= 0) {
-                free(vmlinux_path[vmlinux_path__nr_entries]);
-                vmlinux_path[vmlinux_path__nr_entries] = NULL;
-        }
+        while (--vmlinux_path__nr_entries >= 0)
+                zfree(&vmlinux_path[vmlinux_path__nr_entries]);
 
-        free(vmlinux_path);
-        vmlinux_path = NULL;
+        zfree(&vmlinux_path);
 }
 
 static int vmlinux_path__init(void)
diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index 9b5f856cc280..cf44644a4058 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -9,6 +9,7 @@
 #include "strlist.h"
 #include <string.h>
 #include "thread_map.h"
+#include "util.h"
 
 /* Skip "." and ".." directories */
 static int filter(const struct dirent *dir)
@@ -138,8 +139,7 @@ out_free_namelist:
         free(namelist);
 
 out_free_closedir:
-        free(threads);
-        threads = NULL;
+        zfree(&threads);
         goto out_closedir;
 }
 
@@ -210,8 +210,7 @@ out_free_namelist:
         free(namelist);
 
 out_free_threads:
-        free(threads);
-        threads = NULL;
+        zfree(&threads);
         goto out;
 }
 
@@ -262,8 +261,7 @@ out:
         return threads;
 
 out_free_threads:
-        free(threads);
-        threads = NULL;
+        zfree(&threads);
         goto out;
 }
 
diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index c354b95a2348..9f73bf43862c 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -562,10 +562,8 @@ out:
                 output_fd = fd;
         }
 
-        if (err) {
-                free(tdata);
-                tdata = NULL;
-        }
+        if (err)
+                zfree(&tdata);
 
         put_tracepoints_path(tps);
         return tdata;
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 9a2c268ad718..6995d66f225c 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -186,6 +186,8 @@ static inline void *zalloc(size_t size)
         return calloc(1, size);
 }
 
+#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
+
 static inline int has_extension(const char *filename, const char *ext)
 {
         size_t len = strlen(filename);