diff options
Diffstat (limited to 'avoid-double-destruction-of-ServiceWorkerObjectHost.patch')
| -rw-r--r-- | avoid-double-destruction-of-ServiceWorkerObjectHost.patch | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/avoid-double-destruction-of-ServiceWorkerObjectHost.patch b/avoid-double-destruction-of-ServiceWorkerObjectHost.patch new file mode 100644 index 0000000..5e1df00 --- /dev/null +++ b/avoid-double-destruction-of-ServiceWorkerObjectHost.patch @@ -0,0 +1,138 @@ +From bd59ce32629ef684624821419c43967b73d2989e Mon Sep 17 00:00:00 2001 +From: Hiroki Nakagawa <nhiroki@chromium.org> +Date: Fri, 8 May 2020 08:25:31 +0000 +Subject: [PATCH] ServiceWorker: Avoid double destruction of + ServiceWorkerObjectHost on connection error + +This CL avoids the case where ServiceWorkerObjectHost is destroyed twice +on ServiceWorkerObjectHost::OnConnectionError() when Chromium is built +with the GCC build toolchain. + +> How does the issue happen? + +ServiceWorkerObjectHost has a cyclic reference like this: + +ServiceWorkerObjectHost + --([1] scoped_refptr)--> ServiceWorkerVersion + --([2] std::unique_ptr)--> ServiceWorkerProviderHost + --([3] std::unique_ptr)--> ServiceWorkerContainerHost + --([4] std::unique_ptr)--> ServiceWorkerObjectHost + +Note that ServiceWorkerContainerHost manages ServiceWorkerObjectHost in +map<int64_t version_id, std::unique_ptr<ServiceWorkerObjectHost>>. + +When ServiceWorkerObjectHost::OnConnectionError() is called, the +function removes the reference [4] from the map, and destroys +ServiceWorkerObjectHost. If the object host has the last reference [1] +to ServiceWorkerVersion, the destruction also cuts off the references +[2] and [3], and destroys ServiceWorkerProviderHost and +ServiceWorkerContainerHost. + +This seems to work well on the Chromium's default toolchain, but not +work on the GCC toolchain. According to the report, destruction of +ServiceWorkerContainerHost happens while the map owned by the container +host is erasing the ServiceWorkerObjectHost, and this results in crash +due to double destruction of the object host. + +I don't know the reason why this happens only on the GCC toolchain, but +I suspect the order of object destruction on std::map::erase() could be +different depending on the toolchains. + +> How does this CL fix this? + +The ideal fix is to redesign the ownership model of +ServiceWorkerVersion, but it's not feasible in the short term. + +Instead, this CL avoids destruction of ServiceWorkerObjectHost on +std::map::erase(). The new code takes the ownership of the object host +from the map first, and then erases the entry from the map. This +separates timings to erase the map entry and to destroy the object host, +so the crash should no longer happen. + +Bug: 1056598 +Change-Id: Id30654cb575bc557c42044d6f0c6f1f9bfaed613 +Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094496 +Reviewed-by: Makoto Shimazu <shimazu@chromium.org> +Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org> +Cr-Commit-Position: refs/heads/master@{#766770} +--- + .../service_worker_container_host.cc | 10 +++++ + .../service_worker_object_host_unittest.cc | 38 +++++++++++++++++++ + 2 files changed, 48 insertions(+) + +diff --git a/content/browser/service_worker/service_worker_container_host.cc b/content/browser/service_worker/service_worker_container_host.cc +index ec7fb1449af..98c62093b0e 100644 +--- a/content/browser/service_worker/service_worker_container_host.cc ++++ b/content/browser/service_worker/service_worker_container_host.cc +@@ -669,6 +669,16 @@ void ServiceWorkerContainerHost::RemoveServiceWorkerObjectHost( + int64_t version_id) { + DCHECK_CURRENTLY_ON(ServiceWorkerContext::GetCoreThreadId()); + DCHECK(base::Contains(service_worker_object_hosts_, version_id)); ++ ++ // ServiceWorkerObjectHost to be deleted may have the last reference to ++ // ServiceWorkerVersion that indirectly owns this ServiceWorkerContainerHost. ++ // If we erase the object host directly from the map, |this| could be deleted ++ // during the map operation and may crash. To avoid the case, we take the ++ // ownership of the object host from the map first, and then erase the entry ++ // from the map. See https://crbug.com/1056598 for details. ++ std::unique_ptr<ServiceWorkerObjectHost> to_be_deleted = ++ std::move(service_worker_object_hosts_[version_id]); ++ DCHECK(to_be_deleted); + service_worker_object_hosts_.erase(version_id); + } + +diff --git a/content/browser/service_worker/service_worker_object_host_unittest.cc b/content/browser/service_worker/service_worker_object_host_unittest.cc +index 408d7c1f9d1..6eab59040ab 100644 +--- a/content/browser/service_worker/service_worker_object_host_unittest.cc ++++ b/content/browser/service_worker/service_worker_object_host_unittest.cc +@@ -200,6 +200,19 @@ class ServiceWorkerObjectHostTest : public testing::Test { + return registration_info; + } + ++ void CallOnConnectionError(ServiceWorkerContainerHost* container_host, ++ int64_t version_id) { ++ // ServiceWorkerObjectHost has the last reference to the version. ++ ServiceWorkerObjectHost* object_host = ++ GetServiceWorkerObjectHost(container_host, version_id); ++ EXPECT_TRUE(object_host->version_->HasOneRef()); ++ ++ // Make sure that OnConnectionError induces destruction of the version and ++ // the object host. ++ object_host->receivers_.Clear(); ++ object_host->OnConnectionError(); ++ } ++ + BrowserTaskEnvironment task_environment_; + std::unique_ptr<EmbeddedWorkerTestHelper> helper_; + scoped_refptr<ServiceWorkerRegistration> registration_; +@@ -409,5 +422,30 @@ TEST_F(ServiceWorkerObjectHostTest, DispatchExtendableMessageEvent_FromClient) { + events[0]->source_info_for_client->client_type); + } + ++// This is a regression test for https://crbug.com/1056598. ++TEST_F(ServiceWorkerObjectHostTest, OnConnectionError) { ++ const GURL scope("https://www.example.com/"); ++ const GURL script_url("https://www.example.com/service_worker.js"); ++ Initialize(std::make_unique<EmbeddedWorkerTestHelper>(base::FilePath())); ++ SetUpRegistration(scope, script_url); ++ ++ // Create the provider host. ++ ASSERT_EQ(blink::ServiceWorkerStatusCode::kOk, ++ StartServiceWorker(version_.get())); ++ ++ // Set up the case where the last reference to the version is owned by the ++ // service worker object host. ++ ServiceWorkerContainerHost* container_host = ++ version_->provider_host()->container_host(); ++ ServiceWorkerVersion* version_rawptr = version_.get(); ++ version_ = nullptr; ++ ASSERT_TRUE(version_rawptr->HasOneRef()); ++ ++ // Simulate the connection error that induces the object host destruction. ++ // This shouldn't crash. ++ CallOnConnectionError(container_host, version_rawptr->version_id()); ++ base::RunLoop().RunUntilIdle(); ++} ++ + } // namespace service_worker_object_host_unittest + } // namespace content |