ueventd: remove PlatformDeviceList
In order to create symlinks for USB and block devices, the path for
their parent platform device must be known.
Previously, ueventd would save each platform device that it encounters
to a list and query this list when creating the symlinks. That,
however, is racy because the uevent socket does not differentiate
uevents from RegenerateUevents() and uevents sent by the kernel when
probing a device first the first time. The below scenario is the
faulty case:
1) Kernel probes parent platform device for a block device
2) ueventd calls RegenerateUevents() and starts processing uevents
3) Kernel probes block device and sends its uevents
4) ueventd picks up the block device uevent during its uevent processing,
without yet regenerating the platform device uevent, causing improper
symlinks to be created.
This change stops storing the platform devices in a list, and instead
traverses up the directory structure for each USB or block device
until it reaches a platform device, defined as one whose subsystem is
the platform bus. This fixes the race and simplifies the ueventd
code.
Bug: 62436493
Bug: 62681642
Test: Boot bullhead
Test: Boot sailfish
Test: Init unit tests
Test: Boot hikey + hotplug/unplug sdcard
Change-Id: I21636355d8e434f30e0cba568598a6cf139e67f9
diff --git a/init/devices.h b/init/devices.h
index 09a0ce3..362c38c 100644
--- a/init/devices.h
+++ b/init/devices.h
@@ -93,20 +93,6 @@
DevnameSource devname_source_;
};
-class PlatformDeviceList {
- public:
- void Add(const std::string& path) { platform_devices_.emplace_back(path); }
- void Remove(const std::string& path) {
- auto it = std::find(platform_devices_.begin(), platform_devices_.end(), path);
- if (it != platform_devices_.end()) platform_devices_.erase(it);
- }
- bool Find(const std::string& path, std::string* out_path) const;
- auto size() const { return platform_devices_.size(); }
-
- private:
- std::vector<std::string> platform_devices_;
-};
-
class DeviceHandler {
public:
friend class DeviceHandlerTester;
@@ -119,16 +105,11 @@
void HandleDeviceEvent(const Uevent& uevent);
- void FixupSysPermissions(const std::string& upath, const std::string& subsystem) const;
-
- void HandlePlatformDeviceEvent(const Uevent& uevent);
- void HandleBlockDeviceEvent(const Uevent& uevent) const;
- void HandleGenericDeviceEvent(const Uevent& uevent) const;
-
std::vector<std::string> GetBlockDeviceSymlinks(const Uevent& uevent) const;
void set_skip_restorecon(bool value) { skip_restorecon_ = value; }
private:
+ bool FindPlatformDevice(std::string path, std::string* platform_device_path) const;
std::tuple<mode_t, uid_t, gid_t> GetDevicePermissions(
const std::string& path, const std::vector<std::string>& links) const;
void MakeDevice(const std::string& path, int block, int major, int minor,
@@ -136,13 +117,17 @@
std::vector<std::string> GetCharacterDeviceSymlinks(const Uevent& uevent) const;
void HandleDevice(const std::string& action, const std::string& devpath, int block, int major,
int minor, const std::vector<std::string>& links) const;
+ void FixupSysPermissions(const std::string& upath, const std::string& subsystem) const;
+
+ void HandleBlockDeviceEvent(const Uevent& uevent) const;
+ void HandleGenericDeviceEvent(const Uevent& uevent) const;
std::vector<Permissions> dev_permissions_;
std::vector<SysfsPermissions> sysfs_permissions_;
std::vector<Subsystem> subsystems_;
- PlatformDeviceList platform_devices_;
selabel_handle* sehandle_;
bool skip_restorecon_;
+ std::string sysfs_mount_point_;
};
// Exposed for testing