While refactoring ueventd, I was looking for code the character device
symlinks (/dev/usb/*) that ueventd creates, such that I could test it
on a real device. I found none in our tree, and history showing Xoom,
which was last supported years ago, was the last user. If this code
is in fact obsolete, let's remove it.
Test: boot bullhead
Test: init unit tests
Change-Id: I601f7165eb06d36b31b6dcf69ee9e0a449d81a96
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
devices.cpp handles too many things for creating one class. This
change breaks it up into various files and classes.
* Parsing is moved to ueventd_parser.cpp
* Reading from the uevent socket and Cold booting is moved to a
UeventListener class, in uevent_listener.cpp
* Firmware handling is moved to firmware_handler.cpp
* The remaining contents form a DeviceHandler class within devices.cpp
Bug: 33785894
Test: boot bullhead x40, observe no major differences in /dev and /sys
Test: boot sailfish x40, observe no major differences in /dev and /sys
Test: init unit tests
Change-Id: I846a2e5995fbb344c7a8e349065c18a934fa6aba
Create classes for dev and sys permissions and store these permissions
in std::vector instead of the C list.
Test: boot bullhead
Test: init unit tests
Change-Id: I874039a3db29b4c70149506da8e407123ab7eca2
Also simplify this code a bit.
There's only one consumer that removes the /devices/platform prefix,
so have them handle it instead of storing two copies of the string.
Remove an unneeded search for '/' in get_character_device_symlinks()
as a / will always be the next character after a parent path, by
nature of FindPlatformDevice().
Test: boot bullhead
Test: init unit tests
Change-Id: I9d0482d137b1342ae7509ae993ff99198be814f0
Additionally replace the associated C string parsing with C++ and write
unit tests.
Bug: 33785894
Bug: 36250207
Test: Boot bullhead + unit tests
Change-Id: Iee1f72d248bca3bd2e1227045628935b3dd6195a
