ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

Sun, 19 May 2019 12:07:45 +0000

treewide: Add SPDX license identifier - Makefile/KconfigAdd SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any formThese files fall under the project license, GPL v2 only. The resulting SPDXlicense identifier is: GPL-2.0-onlySigned-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/android/Makefile

3ad20fe3 - binder: implement binderfs

Fri, 14 Dec 2018 12:11:14 +0000

binder: implement binderfsAs discussed at Linux Plumbers Conference 2018 in Vancouver [1] this is theimplementation of binderfs./* Abstract */binderfs is a backwards-compatible filesystem for Android's binder ipcmechanism. Each ipc namespace will mount a new binderfs instance. Mountingbinderfs multiple times at different locations in the same ipc namespacewill not cause a new super block to be allocated and hence it will be thesame filesystem instance.Each new binderfs mount will have its own set of binder devices onlyvisible in the ipc namespace it has been mounted in. All devices in a newbinderfs mount will follow the scheme binder%d and numbering will alwaysstart at 0./* Backwards compatibility */Devices requested in the Kconfig via CONFIG_ANDROID_BINDER_DEVICES for theinitial ipc namespace will work as before. They will be registered viamisc_register() and appear in the devtmpfs mount. Specifically, thestandard devices binder, hwbinder, and vndbinder will all appear in theirstandard locations in /dev. Mounting or unmounting the binderfs mount inthe initial ipc namespace will have no effect on these devices, i.e. theywill neither show up in the binderfs mount nor will they disappear when thebinderfs mount is gone./* binder-control */Each new binderfs instance comes with a binder-control device. No otherdevices will be present at first. The binder-control device can be used todynamically allocate binder devices. All requests operate on the binderfsmount the binder-control device resides in.Assuming a new instance of binderfs has been mounted at /dev/binderfsvia mount -t binderfs binderfs /dev/binderfs. Then a request to create anew binder device can be made as illustrated in [2].Binderfs devices can simply be removed via unlink()./* Implementation details */- dynamic major number allocation: When binderfs is registered as a new filesystem it will dynamically allocate a new major number. The allocated major number will be returned in struct binderfs_device when a new binder device is allocated.- global minor number tracking: Minor are tracked in a global idr struct that is capped at BINDERFS_MAX_MINOR. The minor number tracker is protected by a global mutex. This is the only point of contention between binderfs mounts.- struct binderfs_info: Each binderfs super block has its own struct binderfs_info that tracks specific details about a binderfs instance: - ipc namespace - dentry of the binder-control device - root uid and root gid of the user namespace the binderfs instance was mounted in- mountable by user namespace root: binderfs can be mounted by user namespace root in a non-initial user namespace. The devices will be owned by user namespace root.- binderfs binder devices without misc infrastructure: New binder devices associated with a binderfs mount do not use the full misc_register() infrastructure. The misc_register() infrastructure can only create new devices in the host's devtmpfs mount. binderfs does however only make devices appear under its own mountpoint and thus allocates new character device nodes from the inode of the root dentry of the super block. This will have the side-effect that binderfs specific device nodes do not appear in sysfs. This behavior is similar to devpts allocated pts devices and has no effect on the functionality of the ipc mechanism itself.[1]: https://goo.gl/JL2tfX[2]: program to allocate a new binderfs binder device: #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include int main(int argc, char *argv[]) { int fd, ret, saved_errno; size_t len; struct binderfs_device device = { 0 }; if (argc < 2) exit(EXIT_FAILURE); len = strlen(argv[1]); if (len > BINDERFS_MAX_NAME) exit(EXIT_FAILURE); memcpy(device.name, argv[1], len); fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC); if (fd < 0) { printf("%s - Failed to open binder-control device\n", strerror(errno)); exit(EXIT_FAILURE); } ret = ioctl(fd, BINDER_CTL_ADD, &device); saved_errno = errno; close(fd); errno = saved_errno; if (ret < 0) { printf("%s - Failed to allocate new binder device\n", strerror(errno)); exit(EXIT_FAILURE); } printf("Allocated new binder device with major %d, minor %d, and " "name %s\n", device.major, device.minor, device.name); exit(EXIT_SUCCESS); }Cc: Martijn Coenen Cc: Greg Kroah-Hartman Signed-off-by: Christian Brauner Acked-by: Todd Kjos Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/android/Makefile

4175e2b4 - android: binder: Add allocator selftest

Wed, 23 Aug 2017 15:46:40 +0000

android: binder: Add allocator selftestbinder_alloc_selftest tests that alloc_new_buf handles page allocation anddeallocation properly when allocate and free buffers. The test allocates 5buffers of various sizes to cover all possible page alignment cases, andfrees the buffers using a list of exhaustive freeing order.Test: boot the device with ANDROID_BINDER_IPC_SELFTEST config optionenabled. Allocator selftest passes.Signed-off-by: Sherry Yang Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/android/Makefile

0c972a05 - binder: move binder_alloc to separate file

Thu, 29 Jun 2017 19:01:41 +0000

binder: move binder_alloc to separate fileMove the binder allocator functionality to its own fileContinuation of splitting the binder allocator from the binderdriver. Split binder_alloc functions from normal binder functions.Add kernel doc comments to functions declared extern inbinder_alloc.hSigned-off-by: Todd Kjos Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/android/Makefile

777783e0 - staging: android: binder: move to the "real" part of the kernel

Thu, 16 Oct 2014 12:40:38 +0000

staging: android: binder: move to the "real" part of the kernelThe Android binder code has been "stable" for many years now. No matterwhat comes in the future, we are going to have to support this API, somight as well move it to the "real" part of the kernel as there's noreal work that needs to be done to the existing code.Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/android/Makefile

Changes in Makefile

ec8f24b7 - treewide: Add SPDX license identifier - Makefile/Kconfig

3ad20fe3 - binder: implement binderfs

4175e2b4 - android: binder: Add allocator selftest

0c972a05 - binder: move binder_alloc to separate file

777783e0 - staging: android: binder: move to the "real" part of the kernel