forked from Minki/linux
013e6292aa
11 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Christian Brauner
|
3ad20fe393 |
binder: implement binderfs
As discussed at Linux Plumbers Conference 2018 in Vancouver [1] this is the
implementation of binderfs.
/* Abstract */
binderfs is a backwards-compatible filesystem for Android's binder ipc
mechanism. Each ipc namespace will mount a new binderfs instance. Mounting
binderfs multiple times at different locations in the same ipc namespace
will not cause a new super block to be allocated and hence it will be the
same filesystem instance.
Each new binderfs mount will have its own set of binder devices only
visible in the ipc namespace it has been mounted in. All devices in a new
binderfs mount will follow the scheme binder%d and numbering will always
start at 0.
/* Backwards compatibility */
Devices requested in the Kconfig via CONFIG_ANDROID_BINDER_DEVICES for the
initial ipc namespace will work as before. They will be registered via
misc_register() and appear in the devtmpfs mount. Specifically, the
standard devices binder, hwbinder, and vndbinder will all appear in their
standard locations in /dev. Mounting or unmounting the binderfs mount in
the initial ipc namespace will have no effect on these devices, i.e. they
will neither show up in the binderfs mount nor will they disappear when the
binderfs mount is gone.
/* binder-control */
Each new binderfs instance comes with a binder-control device. No other
devices will be present at first. The binder-control device can be used to
dynamically allocate binder devices. All requests operate on the binderfs
mount the binder-control device resides in.
Assuming a new instance of binderfs has been mounted at /dev/binderfs
via mount -t binderfs binderfs /dev/binderfs. Then a request to create a
new 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 <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/android/binder_ctl.h>
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 <maco@android.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
||
Todd Kjos
|
44d8047f1d |
binder: use standard functions to allocate fds
Binder uses internal fs interfaces to allocate and install fds: __alloc_fd __fd_install __close_fd get_files_struct put_files_struct These were used to support the passing of fds between processes as part of a transaction. The actual allocation and installation of the fds in the target process was handled by the sending process so the standard functions, alloc_fd() and fd_install() which assume task==current couldn't be used. This patch refactors this mechanism so that the fds are allocated and installed by the target process allowing the standard functions to be used. The sender now creates a list of fd fixups that contains the struct *file and the address to fixup with the new fd once it is allocated. This list is processed by the target process when the transaction is dequeued. A new error case is introduced by this change. If an async transaction with file descriptors cannot allocate new fds in the target (probably due to out of file descriptors), the transaction is discarded with a log message. In the old implementation this would have been detected in the sender context and failed prior to sending. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Geert Uytterhoeven
|
2e0e3a24ca |
android: binder: Drop dependency on !M68K
As of commit
|
||
Martijn Coenen
|
1190b4e38f |
ANDROID: binder: remove 32-bit binder interface.
New devices launching with Android P need to use the 64-bit binder interface, even on 32-bit SoCs [0]. This change removes the Kconfig option to select the 32-bit binder interface. We don't think this will affect existing userspace for the following reasons: 1) The latest Android common tree is 4.14, so we don't believe any Android devices are on kernels >4.14. 2) Android devices launch on an LTS release and stick with it, so we wouldn't expect devices running on <= 4.14 now to upgrade to 4.17 or later. But even if they did, they'd rebuild the world (kernel + userspace) anyway. 3) Other userspaces like 'anbox' are already using the 64-bit interface. Note that this change doesn't remove the 32-bit UAPI itself; the reason for that is that Android userspace always uses the latest UAPI headers from upstream, and userspace retains 32-bit support for devices that are upgrading. This will be removed as well in 2-3 years, at which point we can remove the code from the UAPI as well. Finally, this change introduces build errors on archs where 64-bit get_user/put_user is not supported, so make binder unavailable on m68k (which wouldn't want it anyway). [0]: https://android-review.googlesource.com/c/platform/build/+/595193 Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Greg Kroah-Hartman
|
b24413180f |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Sherry Yang
|
4175e2b46f |
android: binder: Add allocator selftest
binder_alloc_selftest tests that alloc_new_buf handles page allocation and deallocation properly when allocate and free buffers. The test allocates 5 buffers of various sizes to cover all possible page alignment cases, and frees the buffers using a list of exhaustive freeing order. Test: boot the device with ANDROID_BINDER_IPC_SELFTEST config option enabled. Allocator selftest passes. Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Jisheng Zhang
|
e8d2ed7db7 |
Revert "staging: Fix build issues with new binder API"
This reverts commit |
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Martijn Coenen
|
9e18d0c82f |
ANDROID: binder: add hwbinder,vndbinder to BINDER_DEVICES.
These will be required going forward. Signed-off-by: Martijn Coenen <maco@android.com> Cc: stable <stable@vger.kernel.org> # 4.11+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Rob Herring
|
dde04eb116 |
binder: Add 'hwbinder' to the default devices
As AOSP master is now starting to require a hwbinder device, add it to the the default Kconfig. Having the hwbinder device when not needed shouldn't hurt anything either. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Martijn Coenen <maco@google.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Serban Constantinescu <serban.constantinescu@arm.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Rom Lemarchand <romlem@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Martijn Coenen
|
ac4812c5ff |
binder: Support multiple /dev instances
Add a new module parameter 'devices', that can be used to specify the names of the binder device nodes we want to populate in /dev. Each device node has its own context manager, and is therefore logically separated from all the other device nodes. The config option CONFIG_ANDROID_BINDER_DEVICES can be used to set the default value of the parameter. This approach was favored over using IPC namespaces, mostly because we require a single process to be a part of multiple binder contexts, which seemed harder to achieve with namespaces. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Martijn Coenen <maco@google.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Serban Constantinescu <serban.constantinescu@arm.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Rom Lemarchand <romlem@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Martijn Coenen <maco@google.com> [jstultz: minor checkpatch warning fix] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Greg Kroah-Hartman
|
777783e0ab |
staging: android: binder: move to the "real" part of the kernel
The Android binder code has been "stable" for many years now. No matter what comes in the future, we are going to have to support this API, so might as well move it to the "real" part of the kernel as there's no real work that needs to be done to the existing code. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |