[PATCH 1/9] perf machine: Propagate machine__init() error to callers

[Arnaldo Carvalho de Melo <acme@kernel.org>]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

machine__init() always returns 0 even when memory allocation fails,
because commit 81f981d7ec43ed93 ("perf machine: Free root_dir in
machine__init() error path") introduced 'int err = -ENOMEM' and an
error cleanup path but left the final 'return 0' instead of
'return err'.

Fix by returning err, check the return value in __machine__new_host()
which was ignoring it, and change machines__init() from void to int so
it too can propagate the error to perf_session__new(), aslr_tool__init()
and test callers.

The error cleanup also used zfree(&machine->kmaps), but kmaps is a
refcounted maps structure — use maps__zput() to properly drop the
reference, matching machine__exit().

Move dsos__init() and threads__init() before the first fallible
allocation (maps__new) so that machine__exit() is safe to call on
any machine struct that machine__init() touched, even on early failure.

Fixes: 81f981d7ec43ed93 ("perf machine: Free root_dir in machine__init() error path")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Assisted-by: Claude <noreply@anthropic.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/hists_cumulate.c    |  3 ++-
 tools/perf/tests/hists_filter.c      |  3 ++-
 tools/perf/tests/hists_link.c        |  3 ++-
 tools/perf/tests/hists_output.c      |  3 ++-
 tools/perf/tests/thread-maps-share.c |  2 +-
 tools/perf/util/aslr.c               | 12 +++++++++---
 tools/perf/util/machine.c            | 24 ++++++++++++++----------
 tools/perf/util/machine.h            |  2 +-
 tools/perf/util/session.c            |  4 +++-
 9 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index 267cbc24691acd77..9f4d4e281e11edaa 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -723,7 +723,8 @@ static int test__hists_cumulate(struct test_suite *test __maybe_unused, int subt
 		goto out;
 	err = TEST_FAIL;
 
-	machines__init(&machines);
+	if (machines__init(&machines))
+		goto out;
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index 002e3a4c1ca59b9d..fa47e995de82d427 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -131,7 +131,8 @@ static int test__hists_filter(struct test_suite *test __maybe_unused, int subtes
 		goto out;
 	err = TEST_FAIL;
 
-	machines__init(&machines);
+	if (machines__init(&machines))
+		goto out;
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 996f5f0b3bd17fe5..05078dac93c4ec6b 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -303,7 +303,8 @@ static int test__hists_link(struct test_suite *test __maybe_unused, int subtest
 		goto out;
 
 	err = TEST_FAIL;
-	machines__init(&machines);
+	if (machines__init(&machines))
+		goto out;
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index fa683fd7b1e5ebb2..1ec51c15b1046eb4 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -610,7 +610,8 @@ static int test__hists_output(struct test_suite *test __maybe_unused, int subtes
 		goto out;
 	err = TEST_FAIL;
 
-	machines__init(&machines);
+	if (machines__init(&machines))
+		goto out;
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
diff --git a/tools/perf/tests/thread-maps-share.c b/tools/perf/tests/thread-maps-share.c
index e9ecd30a5c058076..0431bff31b3a18c3 100644
--- a/tools/perf/tests/thread-maps-share.c
+++ b/tools/perf/tests/thread-maps-share.c
@@ -27,7 +27,7 @@ static int test__thread_maps_share(struct test_suite *test __maybe_unused, int s
 	 * other  group (pid: 4, tids: 4, 5)
 	*/
 
-	machines__init(&machines);
+	TEST_ASSERT_VAL("failed to init machines", machines__init(&machines) == 0);
 	machine = &machines.host;
 
 	/* create process with 4 threads */
diff --git a/tools/perf/util/aslr.c b/tools/perf/util/aslr.c
index a946fff2ac4dd4b4..6a7542e7db827d1b 100644
--- a/tools/perf/util/aslr.c
+++ b/tools/perf/util/aslr.c
@@ -1237,12 +1237,13 @@ void aslr_tool__strip_attr_event(union perf_event *event, struct evlist *evlist)
 	}
 }
 
-static void aslr_tool__init(struct aslr_tool *aslr, struct perf_tool *delegate)
+static int aslr_tool__init(struct aslr_tool *aslr, struct perf_tool *delegate)
 {
 	delegate_tool__init(&aslr->tool, delegate);
 	aslr->tool.tool.ordered_events = true;
 
-	machines__init(&aslr->machines);
+	if (machines__init(&aslr->machines))
+		return -ENOMEM;
 
 	hashmap__init(&aslr->remap_addresses,
 		      remap_addresses__hash, remap_addresses__equal,
@@ -1276,6 +1277,8 @@ static void aslr_tool__init(struct aslr_tool *aslr, struct perf_tool *delegate)
 	aslr->tool.tool.auxtrace = aslr_tool__process_auxtrace;
 	aslr->tool.tool.auxtrace_info = aslr_tool__process_auxtrace_info;
 	aslr->tool.tool.auxtrace_error = aslr_tool__process_auxtrace_error;
+
+	return 0;
 }
 
 struct perf_tool *aslr_tool__new(struct perf_tool *delegate)
@@ -1285,7 +1288,10 @@ struct perf_tool *aslr_tool__new(struct perf_tool *delegate)
 	if (!aslr)
 		return NULL;
 
-	aslr_tool__init(aslr, delegate);
+	if (aslr_tool__init(aslr, delegate)) {
+		free(aslr);
+		return NULL;
+	}
 	return &aslr->tool.tool;
 }
 
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 31715366e29ff704..9329d319bd033699 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -79,15 +79,14 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 	int err = -ENOMEM;
 
 	memset(machine, 0, sizeof(*machine));
-	machine->kmaps = maps__new(machine);
-	if (machine->kmaps == NULL)
-		return -ENOMEM;
-
 	RB_CLEAR_NODE(&machine->rb_node);
 	dsos__init(&machine->dsos);
-
 	threads__init(&machine->threads);
 
+	machine->kmaps = maps__new(machine);
+	if (machine->kmaps == NULL)
+		goto out;
+
 	machine->vdso_info = NULL;
 	machine->env = NULL;
 
@@ -124,11 +123,11 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 
 out:
 	if (err) {
-		zfree(&machine->kmaps);
+		maps__zput(machine->kmaps);
 		zfree(&machine->root_dir);
 		zfree(&machine->mmap_name);
 	}
-	return 0;
+	return err;
 }
 
 static struct machine *__machine__new_host(struct perf_env *host_env, bool kernel_maps)
@@ -138,7 +137,10 @@ static struct machine *__machine__new_host(struct perf_env *host_env, bool kerne
 	if (!machine)
 		return NULL;
 
-	machine__init(machine, "", HOST_KERNEL_ID);
+	if (machine__init(machine, "", HOST_KERNEL_ID) != 0) {
+		free(machine);
+		return NULL;
+	}
 
 	if (kernel_maps && machine__create_kernel_maps(machine) < 0) {
 		free(machine);
@@ -231,10 +233,12 @@ void machine__delete(struct machine *machine)
 	}
 }
 
-void machines__init(struct machines *machines)
+int machines__init(struct machines *machines)
 {
-	machine__init(&machines->host, "", HOST_KERNEL_ID);
+	int err = machine__init(&machines->host, "", HOST_KERNEL_ID);
+
 	machines->guests = RB_ROOT_CACHED;
+	return err;
 }
 
 void machines__exit(struct machines *machines)
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index aaddfb70ea665452..26f9827062f5eb5b 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -152,7 +152,7 @@ struct machines {
 	struct rb_root_cached guests;
 };
 
-void machines__init(struct machines *machines);
+int machines__init(struct machines *machines);
 void machines__exit(struct machines *machines);
 
 void machines__process_guests(struct machines *machines,
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 1a9a008ddda35120..26bacb6c1a572a62 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -160,7 +160,9 @@ struct perf_session *__perf_session__new(struct perf_data *data,
 	session->decomp_data.zstd_decomp = &session->zstd_data;
 	session->active_decomp = &session->decomp_data;
 	INIT_LIST_HEAD(&session->auxtrace_index);
-	machines__init(&session->machines);
+	if (machines__init(&session->machines))
+		goto out_delete;
+
 	ordered_events__init(&session->ordered_events,
 			     ordered_events__deliver_event, NULL);
 
-- 
2.54.0