[PATCH v3 04/50] libperf rc_check: Add RC_CHK_EQUAL
From: Ian Rogers
Date: Tue Oct 24 2023 - 18:24:33 EST
Comparing pointers with reference count checking is tricky to avoid a
SEGV. Add a convenience macro to simplify and use.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/lib/perf/include/internal/rc_check.h | 7 +++++++
tools/perf/builtin-sched.c | 2 +-
tools/perf/tests/hists_link.c | 4 ++--
tools/perf/tests/thread-maps-share.c | 9 ++++-----
tools/perf/util/callchain.c | 2 +-
tools/perf/util/hist.c | 2 +-
tools/perf/util/machine.c | 4 ++--
tools/perf/util/sort.c | 2 +-
tools/perf/util/symbol.c | 4 ++--
9 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/tools/lib/perf/include/internal/rc_check.h b/tools/lib/perf/include/internal/rc_check.h
index e88a6d8a0b0f..f80ddfc80129 100644
--- a/tools/lib/perf/include/internal/rc_check.h
+++ b/tools/lib/perf/include/internal/rc_check.h
@@ -54,6 +54,9 @@
/* A put operation removing the indirection layer. */
#define RC_CHK_PUT(object) {}
+/* Pointer equality when the indirection may or may not be there. */
+#define RC_CHK_EQUAL(object1, object2) (object1 == object2)
+
#else
/* Replaces "struct foo" so that the pointer may be interposed. */
@@ -101,6 +104,10 @@
} \
} while(0)
+/* Pointer equality when the indirection may or may not be there. */
+#define RC_CHK_EQUAL(object1, object2) (object1 == object2 || \
+ (object1 && object2 && object1->orig == object2->orig))
+
#endif
#endif /* __LIBPERF_INTERNAL_RC_CHECK_H */
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 9ab300b6f131..dd6065afbbaf 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1385,7 +1385,7 @@ static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
{
pid_t l_tid, r_tid;
- if (RC_CHK_ACCESS(l->thread) == RC_CHK_ACCESS(r->thread))
+ if (RC_CHK_EQUAL(l->thread, r->thread))
return 0;
l_tid = thread__tid(l->thread);
r_tid = thread__tid(r->thread);
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 2d19657ab5e0..5b6f1e883466 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -148,8 +148,8 @@ static int find_sample(struct sample *samples, size_t nr_samples,
struct thread *t, struct map *m, struct symbol *s)
{
while (nr_samples--) {
- if (RC_CHK_ACCESS(samples->thread) == RC_CHK_ACCESS(t) &&
- RC_CHK_ACCESS(samples->map) == RC_CHK_ACCESS(m) &&
+ if (RC_CHK_EQUAL(samples->thread, t) &&
+ RC_CHK_EQUAL(samples->map, m) &&
samples->sym == s)
return 1;
samples++;
diff --git a/tools/perf/tests/thread-maps-share.c b/tools/perf/tests/thread-maps-share.c
index faf980b26252..7fa6f7c568e2 100644
--- a/tools/perf/tests/thread-maps-share.c
+++ b/tools/perf/tests/thread-maps-share.c
@@ -46,9 +46,9 @@ static int test__thread_maps_share(struct test_suite *test __maybe_unused, int s
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 4);
/* test the maps pointer is shared */
- TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t1)));
- TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t2)));
- TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t3)));
+ TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t1)));
+ TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t2)));
+ TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t3)));
/*
* Verify the other leader was created by previous call.
@@ -73,8 +73,7 @@ static int test__thread_maps_share(struct test_suite *test __maybe_unused, int s
other_maps = thread__maps(other);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(other_maps)), 2);
- TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(other_maps) ==
- RC_CHK_ACCESS(thread__maps(other_leader)));
+ TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(other_maps, thread__maps(other_leader)));
/* release thread group */
thread__put(t3);
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index aee937d14fbb..18d545c0629e 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1142,7 +1142,7 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
if (al->map == NULL)
goto out;
}
- if (RC_CHK_ACCESS(al->maps) == RC_CHK_ACCESS(machine__kernel_maps(machine))) {
+ if (RC_CHK_EQUAL(al->maps, machine__kernel_maps(machine))) {
if (machine__is_host(machine)) {
al->cpumode = PERF_RECORD_MISC_KERNEL;
al->level = 'k';
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 3dc8a4968beb..cde0078e6c90 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -2142,7 +2142,7 @@ static bool hists__filter_entry_by_thread(struct hists *hists,
struct hist_entry *he)
{
if (hists->thread_filter != NULL &&
- RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(hists->thread_filter)) {
+ !RC_CHK_EQUAL(he->thread, hists->thread_filter)) {
he->filtered |= (1 << HIST_FILTER__THREAD);
return true;
}
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index e0e2c4a943e4..098600d983c5 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -969,7 +969,7 @@ static int machine__process_ksymbol_unregister(struct machine *machine,
if (!map)
return 0;
- if (RC_CHK_ACCESS(map) != RC_CHK_ACCESS(machine->vmlinux_map))
+ if (!RC_CHK_EQUAL(map, machine->vmlinux_map))
maps__remove(machine__kernel_maps(machine), map);
else {
struct dso *dso = map__dso(map);
@@ -2058,7 +2058,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread_rb_n
if (!nd)
nd = thread_rb_node__find(th, &threads->entries.rb_root);
- if (threads->last_match && RC_CHK_ACCESS(threads->last_match) == RC_CHK_ACCESS(th))
+ if (threads->last_match && RC_CHK_EQUAL(threads->last_match, th))
threads__set_last_match(threads, NULL);
if (lock)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 6aa1c7f2b444..80e4f6132740 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -128,7 +128,7 @@ static int hist_entry__thread_filter(struct hist_entry *he, int type, const void
if (type != HIST_FILTER__THREAD)
return -1;
- return th && RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(th);
+ return th && !RC_CHK_EQUAL(he->thread, th);
}
struct sort_entry sort_thread = {
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 96587fd7a5a2..822f4dcebfe6 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -877,7 +877,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
*module++ = '\0';
curr_map_dso = map__dso(curr_map);
if (strcmp(curr_map_dso->short_name, module)) {
- if (RC_CHK_ACCESS(curr_map) != RC_CHK_ACCESS(initial_map) &&
+ if (!RC_CHK_EQUAL(curr_map, initial_map) &&
dso->kernel == DSO_SPACE__KERNEL_GUEST &&
machine__is_default_guest(machine)) {
/*
@@ -1469,7 +1469,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
list_del_init(&new_node->node);
- if (RC_CHK_ACCESS(new_map) == RC_CHK_ACCESS(replacement_map)) {
+ if (RC_CHK_EQUAL(new_map, replacement_map)) {
struct map *map_ref;
map__set_start(map, map__start(new_map));
--
2.42.0.758.gaed0368e0e-goog