Merge "ueventd: add support for driver section in ueventd.rc" into main am: 8b7d0aa8c0

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3357138

Change-Id: Iebd84185a6db7a1f3d2df6e8c37d121230c22e3f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

init/README.ueventd.md

@@ -76,17 +76,17 @@ For example
 When `/dev/null` is created, its mode will be set to `0666`, its user to `root` and its group to
 `root`.
 
-The path can be modified using a ueventd.rc script and a `subsystem` section. There are three to set
+The path can be modified using a ueventd.rc script and a `subsystem` and/or `driver` section.
-for a subsystem: the subsystem name, which device name to use, and which directory to place the
+There are three options to set for a subsystem or driver: the name, which device name to use,
-device in. The section takes the below format of
+and which directory to place the device in. The section takes the below format of
 
     subsystem <subsystem_name>
       devname uevent_devname|uevent_devpath
       [dirname <directory>]
 
-`subsystem_name` is used to match uevent `SUBSYSTEM` value
+`subsystem_name` is used to match the uevent `SUBSYSTEM` value.
 
-`devname` takes one of three options
+`devname` takes one of three options:
   1. `uevent_devname` specifies that the name of the node will be the uevent `DEVNAME`
   2. `uevent_devpath` specifies that the name of the node will be basename uevent `DEVPATH`
   3. `sys_name` specifies that the name of the node will be the contents of `/sys/DEVPATH/name`
@@ -99,9 +99,13 @@ For example
     subsystem sound
       devname uevent_devpath
       dirname /dev/snd
-Indicates that all uevents with `SUBSYSTEM=sound` will create nodes as `/dev/snd/<basename uevent
+indicates that all uevents with `SUBSYSTEM=sound` will create nodes as `/dev/snd/<basename uevent
 DEVPATH>`.
 
+The `driver` section has the exact same structure as a `subsystem` section, but
+will instead match the `DRIVER` value in a `bind`/`unbind` uevent. However, the
+`driver` section will be ignored for block devices.
+
 ## /sys
 ----
 Ueventd by default takes no action for `/sys`, however it can be instructed to set permissions for

init/block_dev_initializer.cpp

@@ -33,7 +33,8 @@ BlockDevInitializer::BlockDevInitializer() : uevent_listener_(16 * 1024 * 1024)
     auto boot_devices = android::fs_mgr::GetBootDevices();
     device_handler_ = std::make_unique<DeviceHandler>(
             std::vector<Permissions>{}, std::vector<SysfsPermissions>{}, std::vector<Subsystem>{},
-            std::move(boot_devices), android::fs_mgr::GetBootPartUuid(), false);
+            std::vector<Subsystem>{}, std::move(boot_devices), android::fs_mgr::GetBootPartUuid(),
+            false);
 }
 
 // If boot_part_uuid is specified, use it to set boot_devices

init/devices.cpp

@@ -345,6 +345,26 @@ bool DeviceHandler::FindScsiDevice(const std::string& path, std::string* scsi_de
     return FindSubsystemDevice(path, scsi_device_path, subsystem_paths);
 }
 
+void DeviceHandler::TrackDeviceUevent(const Uevent& uevent) {
+    // No need to track any events if we won't bother handling any bind events
+    // later.
+    if (drivers_.size() == 0) return;
+
+    // Only track add, and not for block devices. We don't track remove because
+    // unbind events may arrive after remove events, so unbind will be the
+    // trigger to untrack those events.
+    if ((uevent.action != "add") || uevent.subsystem == "block" ||
+        (uevent.major < 0 || uevent.minor < 0)) {
+        return;
+    }
+
+    std::string path = sysfs_mount_point_ + uevent.path + "/device";
+    std::string device;
+    if (!Realpath(path, &device)) return;
+
+    tracked_uevents_.emplace_back(uevent, device);
+}
+
 void DeviceHandler::FixupSysPermissions(const std::string& upath,
                                         const std::string& subsystem) const {
     // upaths omit the "/sys" that paths in this list
@@ -664,12 +684,53 @@ bool DeviceHandler::CheckUeventForBootPartUuid(const Uevent& uevent) {
     return true;
 }
 
+void DeviceHandler::HandleBindInternal(std::string driver_name, std::string action,
+                                       const Uevent& uevent) {
+    if (uevent.subsystem == "block") {
+        LOG(FATAL) << "Tried to handle bind event for block device";
+    }
+
+    // Get tracked uevents for all devices that have this uevent's path as
+    // their canonical device path. Then handle those again if their driver
+    // is one of the ones we're interested in.
+    const auto driver = std::find(drivers_.cbegin(), drivers_.cend(), driver_name);
+    if (driver == drivers_.cend()) return;
+
+    std::string bind_path = sysfs_mount_point_ + uevent.path;
+    for (const TrackedUevent& tracked : tracked_uevents_) {
+        if (tracked.canonical_device_path != bind_path) continue;
+
+        LOG(VERBOSE) << "Propagating " << uevent.action << " as " << action << " for "
+                     << uevent.path;
+
+        std::string devpath = driver->ParseDevPath(tracked.uevent);
+        mkdir_recursive(Dirname(devpath), 0755);
+        HandleDevice(action, devpath, false, tracked.uevent.major, tracked.uevent.minor,
+                     std::vector<std::string>{});
+    }
+}
+
 void DeviceHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.action == "add" || uevent.action == "change" || uevent.action == "bind" ||
         uevent.action == "online") {
         FixupSysPermissions(uevent.path, uevent.subsystem);
     }
 
+    if (uevent.action == "bind") {
+        bound_drivers_[uevent.path] = uevent.driver;
+        HandleBindInternal(uevent.driver, "add", uevent);
+        return;
+    } else if (uevent.action == "unbind") {
+        if (bound_drivers_.count(uevent.path) == 0) return;
+        HandleBindInternal(bound_drivers_[uevent.path], "remove", uevent);
+
+        std::string sys_path = sysfs_mount_point_ + uevent.path;
+        std::erase_if(tracked_uevents_, [&sys_path](const TrackedUevent& tracked) {
+            return sys_path == tracked.canonical_device_path;
+        });
+        return;
+    }
+
     // if it's not a /dev device, nothing to do
     if (uevent.major < 0 || uevent.minor < 0) return;
 
@@ -677,6 +738,8 @@ void DeviceHandler::HandleUevent(const Uevent& uevent) {
     std::vector<std::string> links;
     bool block = false;
 
+    TrackDeviceUevent(uevent);
+
     if (uevent.subsystem == "block") {
         block = true;
         devpath = "/dev/block/" + Basename(uevent.path);
@@ -725,10 +788,12 @@ void DeviceHandler::ColdbootDone() {
 
 DeviceHandler::DeviceHandler(std::vector<Permissions> dev_permissions,
                              std::vector<SysfsPermissions> sysfs_permissions,
-                             std::vector<Subsystem> subsystems, std::set<std::string> boot_devices,
+                             std::vector<Subsystem> drivers, std::vector<Subsystem> subsystems,
-                             std::string boot_part_uuid, bool skip_restorecon)
+                             std::set<std::string> boot_devices, std::string boot_part_uuid,
+                             bool skip_restorecon)
     : dev_permissions_(std::move(dev_permissions)),
       sysfs_permissions_(std::move(sysfs_permissions)),
+      drivers_(std::move(drivers)),
       subsystems_(std::move(subsystems)),
       boot_devices_(std::move(boot_devices)),
       boot_part_uuid_(boot_part_uuid),
@@ -744,7 +809,8 @@ DeviceHandler::DeviceHandler(std::vector<Permissions> dev_permissions,
 
 DeviceHandler::DeviceHandler()
     : DeviceHandler(std::vector<Permissions>{}, std::vector<SysfsPermissions>{},
-                    std::vector<Subsystem>{}, std::set<std::string>{}, "", false) {}
+                    std::vector<Subsystem>{}, std::vector<Subsystem>{}, std::set<std::string>{}, "",
+                    false) {}
 
 }  // namespace init
 }  // namespace android

init/devices.h

@@ -21,6 +21,7 @@
 #include <sys/types.h>
 
 #include <algorithm>
+#include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ -128,7 +129,7 @@ class DeviceHandler : public UeventHandler {
 
     DeviceHandler();
     DeviceHandler(std::vector<Permissions> dev_permissions,
-                  std::vector<SysfsPermissions> sysfs_permissions,
+                  std::vector<SysfsPermissions> sysfs_permissions, std::vector<Subsystem> drivers,
                   std::vector<Subsystem> subsystems, std::set<std::string> boot_devices,
                   std::string boot_part_uuid, bool skip_restorecon);
     virtual ~DeviceHandler() = default;
@@ -145,6 +146,11 @@ class DeviceHandler : public UeventHandler {
     bool IsBootDevice(const Uevent& uevent) const;
 
   private:
+    struct TrackedUevent {
+        Uevent uevent;
+        std::string canonical_device_path;
+    };
+
     void ColdbootDone() override;
     BlockDeviceInfo GetBlockDeviceInfo(const std::string& uevent_path) const;
     bool FindSubsystemDevice(std::string path, std::string* device_path,
@@ -163,14 +169,21 @@ class DeviceHandler : public UeventHandler {
     void FixupSysPermissions(const std::string& upath, const std::string& subsystem) const;
     void HandleAshmemUevent(const Uevent& uevent);
 
+    void TrackDeviceUevent(const Uevent& uevent);
+    void HandleBindInternal(std::string driver_name, std::string action, const Uevent& uevent);
+
     std::vector<Permissions> dev_permissions_;
     std::vector<SysfsPermissions> sysfs_permissions_;
+    std::vector<Subsystem> drivers_;
     std::vector<Subsystem> subsystems_;
     std::set<std::string> boot_devices_;
     std::string boot_part_uuid_;
     bool found_boot_part_uuid_;
     bool skip_restorecon_;
     std::string sysfs_mount_point_;
+
+    std::vector<TrackedUevent> tracked_uevents_;
+    std::map<std::string, std::string> bound_drivers_;
 };
 
 // Exposed for testing

init/uevent.h

@@ -26,6 +26,7 @@ struct Uevent {
     std::string action;
     std::string path;
     std::string subsystem;
+    std::string driver;
     std::string firmware;
     std::string partition_name;
     std::string partition_uuid;

init/uevent_listener.cpp

@@ -36,6 +36,7 @@ static void ParseEvent(const char* msg, Uevent* uevent) {
     uevent->action.clear();
     uevent->path.clear();
     uevent->subsystem.clear();
+    uevent->driver.clear();
     uevent->firmware.clear();
     uevent->partition_name.clear();
     uevent->device_name.clear();
@@ -51,6 +52,9 @@ static void ParseEvent(const char* msg, Uevent* uevent) {
         } else if (!strncmp(msg, "SUBSYSTEM=", 10)) {
             msg += 10;
             uevent->subsystem = msg;
+        } else if (!strncmp(msg, "DRIVER=", 7)) {
+            msg += 7;
+            uevent->driver = msg;
         } else if (!strncmp(msg, "FIRMWARE=", 9)) {
             msg += 9;
             uevent->firmware = msg;

init/ueventd.cpp

@@ -364,8 +364,8 @@ int ueventd_main(int argc, char** argv) {
     std::unique_ptr<DeviceHandler> device_handler = std::make_unique<DeviceHandler>(
             std::move(ueventd_configuration.dev_permissions),
             std::move(ueventd_configuration.sysfs_permissions),
-            std::move(ueventd_configuration.subsystems), android::fs_mgr::GetBootDevices(),
+            std::move(ueventd_configuration.drivers), std::move(ueventd_configuration.subsystems),
-            android::fs_mgr::GetBootPartUuid(), true);
+            android::fs_mgr::GetBootDevices(), android::fs_mgr::GetBootPartUuid(), true);
     uevent_listener.RegenerateUevents([&](const Uevent& uevent) -> ListenerAction {
         bool uuid_check_done = device_handler->CheckUeventForBootPartUuid(uevent);
         return uuid_check_done ? ListenerAction::kStop : ListenerAction::kContinue;

init/ueventd_parser.cpp

@@ -264,6 +264,8 @@ UeventdConfiguration ParseConfig(const std::vector<std::string>& configs) {
     parser.AddSectionParser("import", std::make_unique<ImportParser>(&parser));
     parser.AddSectionParser("subsystem",
                             std::make_unique<SubsystemParser>(&ueventd_configuration.subsystems));
+    parser.AddSectionParser("driver",
+                            std::make_unique<SubsystemParser>(&ueventd_configuration.drivers));
 
     using namespace std::placeholders;
     parser.AddSingleLineParser(

init/ueventd_parser.h

@@ -27,6 +27,7 @@ namespace init {
 
 struct UeventdConfiguration {
     std::vector<Subsystem> subsystems;
+    std::vector<Subsystem> drivers;
     std::vector<SysfsPermissions> sysfs_permissions;
     std::vector<Permissions> dev_permissions;
     std::vector<std::string> firmware_directories;

init/ueventd_parser_test.cpp

@@ -106,7 +106,32 @@ subsystem test_devpath_dirname
             {"test_devname2", Subsystem::DEVNAME_UEVENT_DEVNAME, "/dev"},
             {"test_devpath_dirname", Subsystem::DEVNAME_UEVENT_DEVPATH, "/dev/graphics"}};
 
-    TestUeventdFile(ueventd_file, {subsystems, {}, {}, {}, {}, {}});
+    TestUeventdFile(ueventd_file, {subsystems, {}, {}, {}, {}, {}, {}});
+}
+
+TEST(ueventd_parser, Drivers) {
+    auto ueventd_file = R"(
+driver test_devname
+    devname uevent_devname
+
+driver test_devpath_no_dirname
+    devname uevent_devpath
+
+driver test_devname2
+    devname uevent_devname
+
+driver test_devpath_dirname
+    devname uevent_devpath
+    dirname /dev/graphics
+)";
+
+    auto drivers = std::vector<Subsystem>{
+            {"test_devname", Subsystem::DEVNAME_UEVENT_DEVNAME, "/dev"},
+            {"test_devpath_no_dirname", Subsystem::DEVNAME_UEVENT_DEVPATH, "/dev"},
+            {"test_devname2", Subsystem::DEVNAME_UEVENT_DEVNAME, "/dev"},
+            {"test_devpath_dirname", Subsystem::DEVNAME_UEVENT_DEVPATH, "/dev/graphics"}};
+
+    TestUeventdFile(ueventd_file, {{}, drivers, {}, {}, {}, {}, {}, {}});
 }
 
 TEST(ueventd_parser, Permissions) {
@@ -132,7 +157,7 @@ TEST(ueventd_parser, Permissions) {
             {"/sys/devices/virtual/*/input", "poll_delay", 0660, AID_ROOT, AID_INPUT, true},
     };
 
-    TestUeventdFile(ueventd_file, {{}, sysfs_permissions, permissions, {}, {}, {}});
+    TestUeventdFile(ueventd_file, {{}, {}, sysfs_permissions, permissions, {}, {}, {}});
 }
 
 TEST(ueventd_parser, FirmwareDirectories) {
@@ -148,7 +173,7 @@ firmware_directories /more
             "/more",
     };
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, firmware_directories, {}, {}});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, firmware_directories, {}, {}});
 }
 
 TEST(ueventd_parser, ExternalFirmwareHandlers) {
@@ -214,7 +239,7 @@ external_firmware_handler /devices/path/firmware/something004.bin radio radio "/
             },
     };
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, external_firmware_handlers, {}});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, external_firmware_handlers, {}});
 }
 
 TEST(ueventd_parser, ExternalFirmwareHandlersDuplicate) {
@@ -232,7 +257,7 @@ external_firmware_handler devpath root handler_path2
             },
     };
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, external_firmware_handlers, {}});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, external_firmware_handlers, {}});
 }
 
 TEST(ueventd_parser, ParallelRestoreconDirs) {
@@ -246,7 +271,7 @@ parallel_restorecon_dir /sys/devices
             "/sys/devices",
     };
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, parallel_restorecon_dirs});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, {}, parallel_restorecon_dirs});
 }
 
 TEST(ueventd_parser, UeventSocketRcvbufSize) {
@@ -255,7 +280,7 @@ uevent_socket_rcvbuf_size 8k
 uevent_socket_rcvbuf_size 8M
 )";
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, {}, false, 8 * 1024 * 1024});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, {}, {}, false, 8 * 1024 * 1024});
 }
 
 TEST(ueventd_parser, EnabledDisabledLines) {
@@ -265,7 +290,7 @@ parallel_restorecon enabled
 modalias_handling disabled
 )";
 
-    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, {}, false, 0, true});
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, {}, {}, {}, false, 0, true});
 
     auto ueventd_file2 = R"(
 parallel_restorecon enabled
@@ -273,7 +298,7 @@ modalias_handling enabled
 parallel_restorecon disabled
 )";
 
-    TestUeventdFile(ueventd_file2, {{}, {}, {}, {}, {}, {}, true, 0, false});
+    TestUeventdFile(ueventd_file2, {{}, {}, {}, {}, {}, {}, {}, true, 0, false});
 }
 
 TEST(ueventd_parser, AllTogether) {
@@ -286,6 +311,9 @@ firmware_directories /first/ /second /third
 subsystem test_devname
     devname uevent_devname
 
+driver d_test_devpath
+    devname uevent_devpath
+
 /dev/graphics/*           0660   root       graphics
 
 subsystem test_devpath_no_dirname
@@ -303,6 +331,10 @@ subsystem test_devpath_dirname
     devname uevent_devpath
     dirname /dev/graphics
 
+driver d_test_devname_dirname
+    devname uevent_devname
+    dirname /dev/sound
+
 /dev/*/test               0660   root       system
 /sys/devices/virtual/*/input   poll_delay  0660  root   input    no_fnm_pathname
 firmware_directories /more
@@ -325,6 +357,10 @@ parallel_restorecon_dir /sys/devices
             {"test_devname2", Subsystem::DEVNAME_UEVENT_DEVNAME, "/dev"},
             {"test_devpath_dirname", Subsystem::DEVNAME_UEVENT_DEVPATH, "/dev/graphics"}};
 
+    auto drivers = std::vector<Subsystem>{
+            {"d_test_devpath", Subsystem::DEVNAME_UEVENT_DEVPATH, "/dev"},
+            {"d_test_devname_dirname", Subsystem::DEVNAME_UEVENT_DEVNAME, "/dev/graphics"}};
+
     auto permissions = std::vector<Permissions>{
             {"/dev/rtc0", 0640, AID_SYSTEM, AID_SYSTEM, false},
             {"/dev/graphics/*", 0660, AID_ROOT, AID_GRAPHICS, false},
@@ -356,7 +392,7 @@ parallel_restorecon_dir /sys/devices
     size_t uevent_socket_rcvbuf_size = 6 * 1024 * 1024;
 
     TestUeventdFile(ueventd_file,
-                    {subsystems, sysfs_permissions, permissions, firmware_directories,
+                    {subsystems, drivers, sysfs_permissions, permissions, firmware_directories,
                      external_firmware_handlers, parallel_restorecon_dirs, true,
                      uevent_socket_rcvbuf_size, true});
 }