perf annotate: Use zfree() to avoid possibly accessing dangling pointers

When freeing a->b it is good practice to set a->b to NULL using
zfree(&a->b) so that when we have a bug where a reference to a freed 'a'
pointer is kept somewhere, we can more quickly cause a segfault if some
code tries to use a->b.

This is mostly done but some new cases were introduced recently, convert
them to zfree().

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZjmbHHrjIm5YRIBv@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/ui/browsers/annotate-data.c b/tools/perf/ui/browsers/annotate-data.c
index a4a0f042f201a35c5b1aa9ccd99942c57bd530bc..8d6bf08d371dfd235a8f666e859cfa47b2f55199 100644 (file)
--- a/tools/perf/ui/browsers/annotate-data.c
+++ b/tools/perf/ui/browsers/annotate-data.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <inttypes.h>
 #include <string.h>
+#include <linux/zalloc.h>
 #include <sys/ttydefaults.h>
 
 #include "ui/browser.h"
@@ -130,7 +131,7 @@ static void annotated_data_browser__delete_entries(struct annotated_data_browser
 
        list_for_each_entry_safe(pos, tmp, &browser->entries, node) {
                list_del_init(&pos->node);
-               free(pos->hists);
+               zfree(&pos->hists);
                free(pos);
        }
 }

diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index faefa444af1e0d9656bc148ab3f6d3c4c5d59f2e..57e7d4b3550b42f8604893fc10ea78cadefdaab6 100644 (file)
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -8,6 +8,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <inttypes.h>
+#include <linux/zalloc.h>
 
 #include "annotate.h"
 #include "annotate-data.h"
@@ -311,8 +312,8 @@ static void delete_members(struct annotated_member *member)
        list_for_each_entry_safe(child, tmp, &member->children, node) {
                list_del(&child->node);
                delete_members(child);
-               free(child->type_name);
-               free(child->var_name);
+               zfree(&child->type_name);
+               zfree(&child->var_name);
                free(child);
        }
 }
@@ -582,7 +583,7 @@ void global_var_type__tree_delete(struct rb_root *root)
 
                rb_erase(node, root);
                gvar = rb_entry(node, struct global_var_entry, node);
-               free(gvar->name);
+               zfree(&gvar->name);
                free(gvar);
        }
 }
@@ -1817,16 +1818,16 @@ static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_en
 
 err:
        while (--i >= 0)
-               free(adt->histograms[i]);
-       free(adt->histograms);
+               zfree(&(adt->histograms[i]));
+       zfree(&adt->histograms);
        return -ENOMEM;
 }
 
 static void delete_data_type_histograms(struct annotated_data_type *adt)
 {
        for (int i = 0; i < adt->nr_histograms; i++)
-               free(adt->histograms[i]);
-       free(adt->histograms);
+               zfree(&(adt->histograms[i]));
+       zfree(&adt->histograms);
 }
 
 void annotated_data_type__tree_delete(struct rb_root *root)
@@ -1840,7 +1841,7 @@ void annotated_data_type__tree_delete(struct rb_root *root)
                pos = rb_entry(node, struct annotated_data_type, node);
                delete_members(&pos->self);
                delete_data_type_histograms(pos);
-               free(pos->self.type_name);
+               zfree(&pos->self.type_name);
                free(pos);
        }
 }

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index d7d55263fc91b67e221af61b7c50572a631d7a1c..2b178835c1f3c2543068cbb8c69834c75e64bd47 100644 (file)
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -2618,13 +2618,13 @@ static void delete_basic_blocks(struct basic_block_data *bb_data)
 
        list_for_each_entry_safe(link, tmp, &bb_data->queue, node) {
                list_del(&link->node);
-               free(link->bb);
+               zfree(&link->bb);
                free(link);
        }
 
        list_for_each_entry_safe(link, tmp, &bb_data->visited, node) {
                list_del(&link->node);
-               free(link->bb);
+               zfree(&link->bb);
                free(link);
        }
 }