Don't bind-mount bionic files
Bind-mounting of the bionic files on /bionic/* paths no longer required
as there are direct symlinks from bionic files in /system partition to
the corresponding bionic files in the runtime APEX. e.g.,
/system/lib/libc.so -> /apex/com.android.runtime/lib/bionic/libc.so
Bug: 125549215
Test: m; devices boots
Change-Id: I4a43101c3e3e2e14a81001d6d65a8a4b727df385
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 6511d29..8437e37 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -1118,14 +1118,6 @@
}
}
-static Result<Success> do_setup_runtime_bionic(const BuiltinArguments& args) {
- if (SetupRuntimeBionic()) {
- return Success();
- } else {
- return Error() << "Failed to setup runtime bionic";
- }
-}
-
static Result<Success> do_enter_default_mount_ns(const BuiltinArguments& args) {
if (SwitchToDefaultMountNamespace()) {
return Success();
@@ -1181,7 +1173,6 @@
{"rmdir", {1, 1, {true, do_rmdir}}},
{"setprop", {2, 2, {true, do_setprop}}},
{"setrlimit", {3, 3, {false, do_setrlimit}}},
- {"setup_runtime_bionic", {0, 0, {false, do_setup_runtime_bionic}}},
{"start", {1, 1, {false, do_start}}},
{"stop", {1, 1, {false, do_stop}}},
{"swapon_all", {1, 1, {false, do_swapon_all}}},
diff --git a/init/mount_namespace.cpp b/init/mount_namespace.cpp
index 4161df2..5305dc7 100644
--- a/init/mount_namespace.cpp
+++ b/init/mount_namespace.cpp
@@ -33,37 +33,6 @@
namespace init {
namespace {
-static constexpr const char* kLinkerMountPoint = "/bionic/bin/linker";
-static constexpr const char* kBootstrapLinkerPath = "/system/bin/bootstrap/linker";
-static constexpr const char* kRuntimeLinkerPath = "/apex/com.android.runtime/bin/linker";
-
-static constexpr const char* kBionicLibsMountPointDir = "/bionic/lib/";
-static constexpr const char* kBootstrapBionicLibsDir = "/system/lib/bootstrap/";
-static constexpr const char* kRuntimeBionicLibsDir = "/apex/com.android.runtime/lib/bionic/";
-
-static constexpr const char* kLinkerMountPoint64 = "/bionic/bin/linker64";
-static constexpr const char* kBootstrapLinkerPath64 = "/system/bin/bootstrap/linker64";
-static constexpr const char* kRuntimeLinkerPath64 = "/apex/com.android.runtime/bin/linker64";
-
-static constexpr const char* kBionicLibsMountPointDir64 = "/bionic/lib64/";
-static constexpr const char* kBootstrapBionicLibsDir64 = "/system/lib64/bootstrap/";
-static constexpr const char* kRuntimeBionicLibsDir64 = "/apex/com.android.runtime/lib64/bionic/";
-
-static const std::vector<std::string> kBionicLibFileNames = {"libc.so", "libm.so", "libdl.so"};
-
-static bool BindMount(const std::string& source, const std::string& mount_point,
- bool recursive = false) {
- unsigned long mountflags = MS_BIND;
- if (recursive) {
- mountflags |= MS_REC;
- }
- if (mount(source.c_str(), mount_point.c_str(), nullptr, mountflags, nullptr) == -1) {
- PLOG(ERROR) << "Could not bind-mount " << source << " to " << mount_point;
- return false;
- }
- return true;
-}
-
static bool MakeShared(const std::string& mount_point, bool recursive = false) {
unsigned long mountflags = MS_SHARED;
if (recursive) {
@@ -105,34 +74,6 @@
return ret;
}
-static bool BindMountBionic(const std::string& linker_source, const std::string& lib_dir_source,
- const std::string& linker_mount_point,
- const std::string& lib_mount_dir) {
- if (access(linker_source.c_str(), F_OK) != 0) {
- PLOG(INFO) << linker_source << " does not exist. skipping mounting bionic there.";
- // This can happen for 64-bit bionic in 32-bit only device.
- // It is okay to skip mounting the 64-bit bionic.
- return true;
- }
- if (!BindMount(linker_source, linker_mount_point)) {
- return false;
- }
- if (!MakePrivate(linker_mount_point)) {
- return false;
- }
- for (const auto& libname : kBionicLibFileNames) {
- std::string mount_point = lib_mount_dir + libname;
- std::string source = lib_dir_source + libname;
- if (!BindMount(source, mount_point)) {
- return false;
- }
- if (!MakePrivate(mount_point)) {
- return false;
- }
- }
- return true;
-}
-
static bool IsApexUpdatable() {
static bool updatable = android::sysprop::ApexProperties::updatable().value_or(false);
return updatable;
@@ -154,26 +95,7 @@
// point to private.
if (!MakeShared("/", true /*recursive*/)) return false;
- // Since different files (bootstrap or runtime APEX) should be mounted to
- // the same mount point paths (e.g. /bionic/bin/linker, /bionic/lib/libc.so,
- // etc.) across the two mount namespaces, we create a private mount point at
- // /bionic so that a mount event for the bootstrap bionic in the mount
- // namespace for pre-apexd processes is not propagated to the other mount
- // namespace for post-apexd process, and vice versa.
- //
- // Other mount points other than /bionic, however, are all still shared.
- if (!BindMount("/bionic", "/bionic", true /*recursive*/)) return false;
- if (!MakePrivate("/bionic")) return false;
-
- // Bind-mount bootstrap bionic.
- if (!BindMountBionic(kBootstrapLinkerPath, kBootstrapBionicLibsDir, kLinkerMountPoint,
- kBionicLibsMountPointDir))
- return false;
- if (!BindMountBionic(kBootstrapLinkerPath64, kBootstrapBionicLibsDir64, kLinkerMountPoint64,
- kBionicLibsMountPointDir64))
- return false;
-
- // /apex is also a private mountpoint to give different sets of APEXes for
+ // /apex is a private mountpoint to give different sets of APEXes for
// the bootstrap and default mount namespaces. The processes running with
// the bootstrap namespace get APEXes from the read-only partition.
if (!(MakePrivate("/apex"))) return false;
@@ -181,12 +103,11 @@
bootstrap_ns_fd.reset(OpenMountNamespace());
bootstrap_ns_id = GetMountNamespaceId();
- // When bionic is updatable via the runtime APEX, we create separate mount
+ // When APEXes are updatable (e.g. not-flattened), we create separate mount
// namespaces for processes that are started before and after the APEX is
- // activated by apexd. In the namespace for pre-apexd processes, the bionic
- // from the /system partition (that we call bootstrap bionic) is
- // bind-mounted. In the namespace for post-apexd processes, the bionic from
- // the runtime APEX is bind-mounted.
+ // activated by apexd. In the namespace for pre-apexd processes, small
+ // number of essential APEXes (e.g. com.android.runtime) are activated.
+ // In the namespace for post-apexd processes, all APEXes are activated.
bool success = true;
if (IsApexUpdatable() && !IsRecoveryMode()) {
// Creating a new namespace by cloning, saving, and switching back to
@@ -198,15 +119,6 @@
default_ns_fd.reset(OpenMountNamespace());
default_ns_id = GetMountNamespaceId();
- // By this unmount, the bootstrap bionic are not mounted in the default
- // mount namespace.
- if (umount2("/bionic", MNT_DETACH) == -1) {
- PLOG(ERROR) << "Cannot unmount /bionic";
- // Don't return here. We have to switch back to the bootstrap
- // namespace.
- success = false;
- }
-
if (setns(bootstrap_ns_fd.get(), CLONE_NEWNS) == -1) {
PLOG(ERROR) << "Cannot switch back to bootstrap mount namespace";
return false;
@@ -237,28 +149,6 @@
return true;
}
-// TODO(jiyong): remove this when /system/lib/libc.so becomes
-// a symlink to /apex/com.android.runtime/lib/bionic/libc.so
-bool SetupRuntimeBionic() {
- if (IsRecoveryMode()) {
- // We don't have multiple namespaces in recovery mode
- return true;
- }
- // Bind-mount bionic from the runtime APEX since it is now available. Note
- // that in case of IsApexUpdatable() == false, these mounts are over the
- // existing existing bind mounts for the bootstrap bionic, which effectively
- // becomes hidden.
- if (!BindMountBionic(kRuntimeLinkerPath, kRuntimeBionicLibsDir, kLinkerMountPoint,
- kBionicLibsMountPointDir))
- return false;
- if (!BindMountBionic(kRuntimeLinkerPath64, kRuntimeBionicLibsDir64, kLinkerMountPoint64,
- kBionicLibsMountPointDir64))
- return false;
-
- LOG(INFO) << "Runtime bionic is set up";
- return true;
-}
-
bool SwitchToBootstrapMountNamespaceIfNeeded() {
if (IsRecoveryMode()) {
// we don't have multiple namespaces in recovery mode
diff --git a/init/mount_namespace.h b/init/mount_namespace.h
index 4eef785..c41a449 100644
--- a/init/mount_namespace.h
+++ b/init/mount_namespace.h
@@ -20,7 +20,6 @@
namespace init {
bool SetupMountNamespaces();
-bool SetupRuntimeBionic();
bool SwitchToDefaultMountNamespace();
bool SwitchToBootstrapMountNamespaceIfNeeded();
diff --git a/rootdir/etc/ld.config.txt b/rootdir/etc/ld.config.txt
index 552d685..641a536 100644
--- a/rootdir/etc/ld.config.txt
+++ b/rootdir/etc/ld.config.txt
@@ -83,7 +83,7 @@
namespace.default.permitted.paths += /%PRODUCT_SERVICES%/priv-app
namespace.default.permitted.paths += /data
namespace.default.permitted.paths += /mnt/expand
-namespace.default.permitted.paths += /bionic/${LIB}
+namespace.default.permitted.paths += /apex/com.android.runtime/${LIB}/bionic
namespace.default.permitted.paths += /system/${LIB}/bootstrap
namespace.default.asan.search.paths = /data/asan/system/${LIB}
@@ -119,7 +119,7 @@
namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/app
namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/priv-app
namespace.default.asan.permitted.paths += /mnt/expand
-namespace.default.asan.permitted.paths += /bionic/${LIB}
+namespace.default.asan.permitted.paths += /apex/com.android.runtime/${LIB}/bionic
namespace.default.asan.permitted.paths += /system/${LIB}/bootstrap
# Keep in sync with ld.config.txt in the com.android.runtime APEX.
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 7cac972..3298ffd 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -578,8 +578,6 @@
# Wait for apexd to finish activating APEXes before starting more processes.
wait_for_prop apexd.status ready
- # TODO(jiyong): remove setup_runtime_bionic
- setup_runtime_bionic
parse_apex_configs
init_user0