Commit Graph

150 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>
2018-12-19 09:40:13 +01:00
Todd Kjos 80cd795630 binder: fix use-after-free due to ksys_close() during fdget()
44d8047f1d ("binder: use standard functions to allocate fds")
exposed a pre-existing issue in the binder driver.

fdget() is used in ksys_ioctl() as a performance optimization.
One of the rules associated with fdget() is that ksys_close() must
not be called between the fdget() and the fdput(). There is a case
where this requirement is not met in the binder driver which results
in the reference count dropping to 0 when the device is still in
use. This can result in use-after-free or other issues.

If userpace has passed a file-descriptor for the binder driver using
a BINDER_TYPE_FDA object, then kys_close() is called on it when
handling a binder_ioctl(BC_FREE_BUFFER) command. This violates
the assumptions for using fdget().

The problem is fixed by deferring the close using task_work_add(). A
new variant of __close_fd() was created that returns a struct file
with a reference. The fput() is deferred instead of using ksys_close().

Fixes: 44d8047f1d ("binder: use standard functions to allocate fds")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 09:40:13 +01:00
Todd Kjos ecd589d8f5 binder: filter out nodes when showing binder procs
When dumping out binder transactions via a debug node,
the output is too verbose if a process has many nodes.
Change the output for transaction dumps to only display
nodes with pending async transactions.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 15:44:14 +01:00
Todd Kjos 7a2670a5bc binder: fix kerneldoc header for struct binder_buffer
Fix the incomplete kerneldoc header for struct binder_buffer.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 15:44:14 +01:00
Yangtao Li c13e0a5288 binder: remove BINDER_DEBUG_ENTRY()
We already have the DEFINE_SHOW_ATTRIBUTE.There is no need to define
such a macro,so remove BINDER_DEBUG_ENTRY.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Todd Kjos <tkjos@android.com>
Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 15:42:18 +01:00
Greg Kroah-Hartman 22fee7d385 Merge 4.20-rc5 into char-misc-next
We need the fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-03 07:56:15 +01:00
Todd Kjos 324fa64cf4 binder: fix sparse warnings on locking context
Add __acquire()/__release() annnotations to fix warnings
in sparse context checking

There is one case where the warning was due to a lack of
a "default:" case in a switch statement where a lock was
being released in each of the cases, so the default
case was added.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26 20:12:05 +01:00
Todd Kjos 7bada55ab5 binder: fix race that allows malicious free of live buffer
Malicious code can attempt to free buffers using the BC_FREE_BUFFER
ioctl to binder. There are protections against a user freeing a buffer
while in use by the kernel, however there was a window where
BC_FREE_BUFFER could be used to free a recently allocated buffer that
was not completely initialized. This resulted in a use-after-free
detected by KASAN with a malicious test program.

This window is closed by setting the buffer's allow_user_free attribute
to 0 when the buffer is allocated or when the user has previously freed
it instead of waiting for the caller to set it. The problem was that
when the struct buffer was recycled, allow_user_free was stale and set
to 1 allowing a free to go through.

Signed-off-by: Todd Kjos <tkjos@google.com>
Acked-by: Arve Hjønnevåg <arve@android.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26 20:01:47 +01:00
Wei Yongjun f4608ce917 binder: make symbol 'binder_free_buf' static
Fixes the following sparse warning:

drivers/android/binder.c:3312:1: warning:
 symbol 'binder_free_buf' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 15:53:53 -07:00
Greg Kroah-Hartman f685fc6ab0 Merge b4.19-rc4 into char-misc-next
We want the bugfixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-16 22:41:47 +02:00
Martijn Coenen b7e6a8961b binder: Add BINDER_GET_NODE_INFO_FOR_REF ioctl.
This allows the context manager to retrieve information about nodes
that it holds a reference to, such as the current number of
references to those nodes.

Such information can for example be used to determine whether the
servicemanager is the only process holding a reference to a node.
This information can then be passed on to the process holding the
node, which can in turn decide whether it wants to shut down to
reduce resource usage.

Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-14 15:22:48 +02:00
Rasmus Villemoes 6b6642dadd android: binder: use kstrdup instead of open-coding it
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-14 15:22:36 +02:00
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>
2018-09-14 15:22:36 +02:00
Sherry Yang 44b73962cb android: binder: no outgoing transaction when thread todo has transaction
When a process dies, failed reply is sent to the sender of any transaction
queued on a dead thread's todo list. The sender asserts that the
received failed reply corresponds to the head of the transaction stack.
This assert can fail if the dead thread is allowed to send outgoing
transactions when there is already a transaction on its todo list,
because this new transaction can end up on the transaction stack of the
original sender. The following steps illustrate how this assertion can
fail.

1. Thread1 sends txn19 to Thread2
   (T1->transaction_stack=txn19, T2->todo+=txn19)
2. Without processing todo list, Thread2 sends txn20 to Thread1
   (T1->todo+=txn20, T2->transaction_stack=txn20)
3. T1 processes txn20 on its todo list
   (T1->transaction_stack=txn20->txn19, T1->todo=<empty>)
4. T2 dies, T2->todo cleanup attempts to send failed reply for txn19, but
   T1->transaction_stack points to txn20 -- assertion failes

Step 2. is the incorrect behavior. When there is a transaction on a
thread's todo list, this thread should not be able to send any outgoing
synchronous transactions. Only the head of the todo list needs to be
checked because only threads that are waiting for proc work can directly
receive work from another thread, and no work is allowed to be queued
on such a thread without waking up the thread. This patch also enforces
that a thread is not waiting for proc work when a work is directly
enqueued to its todo list.

Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Reviewed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-14 15:22:36 +02:00
Minchan Kim da1b9564e8 android: binder: fix the race mmap and alloc_new_buf_locked
There is RaceFuzzer report like below because we have no lock to close
below the race between binder_mmap and binder_alloc_new_buf_locked.
To close the race, let's use memory barrier so that if someone see
alloc->vma is not NULL, alloc->vma_vm_mm should be never NULL.

(I didn't add stable mark intentionallybecause standard android
userspace libraries that interact with binder (libbinder & libhwbinder)
prevent the mmap/ioctl race. - from Todd)

"
Thread interleaving:
CPU0 (binder_alloc_mmap_handler)              CPU1 (binder_alloc_new_buf_locked)
=====                                         =====
// drivers/android/binder_alloc.c
// #L718 (v4.18-rc3)
alloc->vma = vma;
                                              // drivers/android/binder_alloc.c
                                              // #L346 (v4.18-rc3)
                                              if (alloc->vma == NULL) {
                                                  ...
                                                  // alloc->vma is not NULL at this point
                                                  return ERR_PTR(-ESRCH);
                                              }
                                              ...
                                              // #L438
                                              binder_update_page_range(alloc, 0,
                                                      (void *)PAGE_ALIGN((uintptr_t)buffer->data),
                                                      end_page_addr);

                                              // In binder_update_page_range() #L218
                                              // But still alloc->vma_vm_mm is NULL here
                                              if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
alloc->vma_vm_mm = vma->vm_mm;

Crash Log:
==================================================================
BUG: KASAN: null-ptr-deref in __atomic_add_unless include/asm-generic/atomic-instrumented.h:89 [inline]
BUG: KASAN: null-ptr-deref in atomic_add_unless include/linux/atomic.h:533 [inline]
BUG: KASAN: null-ptr-deref in mmget_not_zero include/linux/sched/mm.h:75 [inline]
BUG: KASAN: null-ptr-deref in binder_update_page_range+0xece/0x18e0 drivers/android/binder_alloc.c:218
Write of size 4 at addr 0000000000000058 by task syz-executor0/11184

CPU: 1 PID: 11184 Comm: syz-executor0 Not tainted 4.18.0-rc3 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x16e/0x22c lib/dump_stack.c:113
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report+0x163/0x380 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x140/0x1a0 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 __atomic_add_unless include/asm-generic/atomic-instrumented.h:89 [inline]
 atomic_add_unless include/linux/atomic.h:533 [inline]
 mmget_not_zero include/linux/sched/mm.h:75 [inline]
 binder_update_page_range+0xece/0x18e0 drivers/android/binder_alloc.c:218
 binder_alloc_new_buf_locked drivers/android/binder_alloc.c:443 [inline]
 binder_alloc_new_buf+0x467/0xc30 drivers/android/binder_alloc.c:513
 binder_transaction+0x125b/0x4fb0 drivers/android/binder.c:2957
 binder_thread_write+0xc08/0x2770 drivers/android/binder.c:3528
 binder_ioctl_write_read.isra.39+0x24f/0x8e0 drivers/android/binder.c:4456
 binder_ioctl+0xa86/0xf34 drivers/android/binder.c:4596
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x154/0xd40 fs/ioctl.c:686
 ksys_ioctl+0x94/0xb0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:706
 do_syscall_64+0x167/0x4b0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
"

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-12 09:18:29 +02:00
Sherry Yang 128f380410 android: binder: Rate-limit debug and userspace triggered err msgs
Use rate-limited debug messages where userspace can trigger
excessive log spams.

Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-08 11:05:47 +02:00
Sherry Yang c8c64b39cf android: binder: Show extra_buffers_size in trace
Add extra_buffers_size to the binder_transaction_alloc_buf tracepoint.

Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02 10:34:12 +02:00
Guenter Roeck f371a7c17a android: binder: Include asm/cacheflush.h after linux/ include files
If asm/cacheflush.h is included first, the following build warnings are
seen with sparc32 builds.

In file included from arch/sparc/include/asm/cacheflush.h:11:0,
        from drivers/android/binder.c:54:
arch/sparc/include/asm/cacheflush_32.h:40:37: warning:
	'struct page' declared inside parameter list will not be visible
	outside of this definition or declaration

Moving the asm/ include after linux/ includes solves the problem.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-24 14:23:00 +02:00
Guenter Roeck 1e81c57b59 android: binder_alloc: Include asm/cacheflush.h after linux/ include files
If asm/cacheflush.h is included first, the following build warnings are
seen with sparc32 builds.

In file included from ./arch/sparc/include/asm/cacheflush.h:11:0,
	from drivers/android/binder_alloc.c:20:
./arch/sparc/include/asm/cacheflush_32.h:40:37: warning:
	'struct page' declared inside parameter list

Moving the asm/ include after linux/ includes fixes the problem.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-24 14:23:00 +02:00
Geert Uytterhoeven 2e0e3a24ca android: binder: Drop dependency on !M68K
As of commit 7124330dab ("m68k/uaccess: Revive 64-bit
get_user()"), the 64-bit Android binder interface builds fine on m68k.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-07 17:44:52 +02:00
Kees Cook 6396bb2215 treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Souptick Joarder e19f70aa02 android: binder: Change return type to vm_fault_t
Use new return type vm_fault_t for fault handler in
struct vm_operations_struct. For now, this is just
documenting that the function returns a VM_FAULT
value rather than an errno.  Once all instances are
converted, vm_fault_t will become a distinct type.

Reference id -> 1c8f422059 ("mm: change return type
to vm_fault_t")

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:06:48 +02:00
Minchan Kim 720c241924 ANDROID: binder: change down_write to down_read
binder_update_page_range needs down_write of mmap_sem because
vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless
it is set. However, when I profile binder working, it seems
every binder buffers should be mapped in advance by binder_mmap.
It means we could set VM_MIXEDMAP in binder_mmap time which is
already hold a mmap_sem as down_write so binder_update_page_range
doesn't need to hold a mmap_sem as down_write.
Please use proper API down_read. It would help mmap_sem contention
problem as well as fixing down_write abuse.

Ganesh Mahendran tested app launching and binder throughput test
and he said he couldn't find any problem and I did binder latency
test per Greg KH request(Thanks Martijn to teach me how I can do)
I cannot find any problem, too.

Cc: Ganesh Mahendran <opensource.ganesh@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Todd Kjos <tkjos@google.com>
Reviewed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:06:48 +02:00
宋金时 838d556566 ANDROID: binder: correct the cmd print for BINDER_WORK_RETURN_ERROR
When to execute binder_stat_br the e->cmd has been modifying as BR_OK
instead of the original return error cmd, in fact we want to know the
original return error, such as BR_DEAD_REPLY or BR_FAILED_REPLY, etc.
instead of always BR_OK, in order to avoid the value of the e->cmd is
always BR_OK, so we need assign the value of the e->cmd to cmd before
e->cmd = BR_OK.

Signed-off-by: songjinshi <songjinshi@xiaomi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:06:48 +02:00
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>
2018-05-14 16:06:48 +02:00
Greg Kroah-Hartman 720d690e36 Merge 4.17-rc3 into char-misc-next
We want the fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-30 05:05:54 -07:00
Dan Carpenter 361f2ddbb0 ANDROID: binder: re-order some conditions
It doesn't make any difference to runtime but I've switched these two
checks to make my static checker happy.

The problem is that "buffer->data_size" is user controlled and if it's
less than "sizeo(*hdr)" then that means "offset" can be more than
"buffer->data_size".  It's just cleaner to check it in the other order.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 12:14:37 +02:00
Martijn Coenen 7aa135fcf2 ANDROID: binder: prevent transactions into own process.
This can't happen with normal nodes (because you can't get a ref
to a node you own), but it could happen with the context manager;
to make the behavior consistent with regular nodes, reject
transactions into the context manager by the process owning it.

Reported-by: syzbot+09e05aba06723a94d43d@syzkaller.appspotmail.com
Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 12:12:41 +02:00
Martijn Coenen 5eeb2ca02a ANDROID: binder: synchronize_rcu() when using POLLFREE.
To prevent races with ep_remove_waitqueue() removing the
waitqueue at the same time.

Reported-by: syzbot+a2a3c4909716e271487e@syzkaller.appspotmail.com
Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org> # 4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16 11:16:38 +01:00
Todd Kjos 8ca86f1639 binder: replace "%p" with "%pK"
The format specifier "%p" can leak kernel addresses. Use
"%pK" instead. There were 4 remaining cases in binder.c.

Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16 11:16:38 +01:00
Todd Kjos e46a3b3ba7 ANDROID: binder: remove WARN() for redundant txn error
binder_send_failed_reply() is called when a synchronous
transaction fails. It reports an error to the thread that
is waiting for the completion. Given that the transaction
is synchronous, there should never be more than 1 error
response to that thread -- this was being asserted with
a WARN().

However, when exercising the driver with syzbot tests, cases
were observed where multiple "synchronous" requests were
sent without waiting for responses, so it is possible that
multiple errors would be reported to the thread. This testing
was conducted with panic_on_warn set which forced the crash.

This is easily reproduced by sending back-to-back
"synchronous" transactions without checking for any
response (eg, set read_size to 0):

    bwr.write_buffer = (uintptr_t)&bc1;
    bwr.write_size = sizeof(bc1);
    bwr.read_buffer = (uintptr_t)&br;
    bwr.read_size = 0;
    ioctl(fd, BINDER_WRITE_READ, &bwr);
    sleep(1);
    bwr2.write_buffer = (uintptr_t)&bc2;
    bwr2.write_size = sizeof(bc2);
    bwr2.read_buffer = (uintptr_t)&br;
    bwr2.read_size = 0;
    ioctl(fd, BINDER_WRITE_READ, &bwr2);
    sleep(1);

The first transaction is sent to the servicemanager and the reply
fails because no VMA is set up by this client. After
binder_send_failed_reply() is called, the BINDER_WORK_RETURN_ERROR
is sitting on the thread's todo list since the read_size was 0 and
the client is not waiting for a response.

The 2nd transaction is sent and the BINDER_WORK_RETURN_ERROR has not
been consumed, so the thread's reply_error.cmd is still set (normally
cleared when the BINDER_WORK_RETURN_ERROR is handled). Therefore
when the servicemanager attempts to reply to the 2nd failed
transaction, the error is already set and it triggers this warning.

This is a user error since it is not waiting for the synchronous
transaction to complete. If it ever does check, it will see an
error.

Changed the WARN() to a pr_warn().

Signed-off-by: Todd Kjos <tkjos@android.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16 11:15:45 +01:00
Eric Biggers f88982679f binder: check for binder_thread allocation failure in binder_poll()
If the kzalloc() in binder_get_thread() fails, binder_poll()
dereferences the resulting NULL pointer.

Fix it by returning POLLERR if the memory allocation failed.

This bug was found by syzkaller using fault injection.

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 457b9a6f09 ("Staging: android: add binder driver")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16 11:15:44 +01:00
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Linus Torvalds f6cff79f1d Char/Misc driver patches for 4.16-rc1
Here is the big pull request for char/misc drivers for 4.16-rc1.
 
 There's a lot of stuff in here.  Three new driver subsystems were added
 for various types of hardware busses:
 	- siox
 	- slimbus
 	- soundwire
 as well as a new vboxguest subsystem for the VirtualBox hypervisor
 drivers.
 
 There's also big updates from the FPGA subsystem, lots of Android binder
 fixes, the usual handful of hyper-v updates, and lots of other smaller
 driver updates.
 
 All of these have been in linux-next for a long time, with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big pull request for char/misc drivers for 4.16-rc1.

  There's a lot of stuff in here. Three new driver subsystems were added
  for various types of hardware busses:

   - siox
   - slimbus
   - soundwire

  as well as a new vboxguest subsystem for the VirtualBox hypervisor
  drivers.

  There's also big updates from the FPGA subsystem, lots of Android
  binder fixes, the usual handful of hyper-v updates, and lots of other
  smaller driver updates.

  All of these have been in linux-next for a long time, with no reported
  issues"

* tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (155 commits)
  char: lp: use true or false for boolean values
  android: binder: use VM_ALLOC to get vm area
  android: binder: Use true and false for boolean values
  lkdtm: fix handle_irq_event symbol for INT_HW_IRQ_EN
  EISA: Delete error message for a failed memory allocation in eisa_probe()
  EISA: Whitespace cleanup
  misc: remove AVR32 dependencies
  virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES
  soundwire: Fix a signedness bug
  uio_hv_generic: fix new type mismatch warnings
  uio_hv_generic: fix type mismatch warnings
  auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  uio_hv_generic: add rescind support
  uio_hv_generic: check that host supports monitor page
  uio_hv_generic: create send and receive buffers
  uio: document uio_hv_generic regions
  doc: fix documentation about uio_hv_generic
  vmbus: add monitor_id and subchannel_id to sysfs per channel
  vmbus: fix ABI documentation
  uio_hv_generic: use ISR callback method
  ...
2018-02-01 10:31:17 -08:00
Linus Torvalds 168fe32a07 Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...
2018-01-30 17:58:07 -08:00
Ganesh Mahendran aac6830ec1 android: binder: use VM_ALLOC to get vm area
VM_IOREMAP is used to access hardware through a mechanism called
I/O mapped memory. Android binder is a IPC machanism which will
not access I/O memory.

And VM_IOREMAP has alignment requiement which may not needed in
binder.
    __get_vm_area_node()
    {
    ...
        if (flags & VM_IOREMAP)
            align = 1ul << clamp_t(int, fls_long(size),
               PAGE_SHIFT, IOREMAP_MAX_ORDER);
    ...
    }

This patch will save some kernel vm area, especially for 32bit os.

In 32bit OS, kernel vm area is only 240MB. We may got below
error when launching a app:

<3>[ 4482.440053] binder_alloc: binder_alloc_mmap_handler: 15728 8ce67000-8cf65000 get_vm_area failed -12
<3>[ 4483.218817] binder_alloc: binder_alloc_mmap_handler: 15745 8ce67000-8cf65000 get_vm_area failed -12

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Martijn Coenen <maco@android.com>
Acked-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>

----
V3: update comments
V2: update comments
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-25 10:46:42 +01:00
Gustavo A. R. Silva 197410ad88 android: binder: Use true and false for boolean values
Assign true or false to boolean variables instead of an integer value.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-25 10:46:42 +01:00
Harsh Shandilya 21d02ddf71 android: binder: Use octal permissions
checkpatch warns against the use of symbolic permissions,
this patch migrates all symbolic permissions in the binder
driver to octal permissions.

Test: debugfs nodes created by binder have the same unix
permissions prior to and after this patch was applied.

Signed-off-by: Harsh Shandilya <harsh@prjkt.io>
Cc: "Arve Hjønnevåg" <arve@android.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 18:00:45 +01:00
Martijn Coenen e940c10875 ANDROID: binder: Remove obsolete proc waitqueue.
It was no longer being used.

Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 17:59:21 +01:00
Martijn Coenen f5cb779ba1 ANDROID: binder: remove waitqueue when thread exits.
binder_poll() passes the thread->wait waitqueue that
can be slept on for work. When a thread that uses
epoll explicitly exits using BINDER_THREAD_EXIT,
the waitqueue is freed, but it is never removed
from the corresponding epoll data structure. When
the process subsequently exits, the epoll cleanup
code tries to access the waitlist, which results in
a use-after-free.

Prevent this by using POLLFREE when the thread exits.

Signed-off-by: Martijn Coenen <maco@android.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 17:54:01 +01:00
Elad Wexler 00c41cddeb android: binder: Prefer __func__ to using hardcoded function name
Coding style fixup

Signed-off-by: Elad Wexler <elad.wexler@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 17:05:32 +01:00
Greg Kroah-Hartman b6a09416e8 Merge 4.15-rc6 into char-misc-next
We want the fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02 14:46:35 +01:00
Xiongwei Song 3f82724546 ANDROID: binder: make binder_alloc_new_buf_locked static and indent its arguments
The function binder_alloc_new_buf_locked() is only used in this file, so
make it static. Also clean up sparse warning:

drivers/android/binder_alloc.c:330:23: warning: no previous prototype
for ‘binder_alloc_new_buf_locked’ [-Wmissing-prototypes]

In addition, the line of the function name exceeds 80 characters when
add static for this function, hence indent its arguments anew.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19 10:12:57 +01:00
Tetsuo Handa 533dfb250d android: binder: Check for errors in binder_alloc_shrinker_init().
Both list_lru_init() and register_shrinker() might return an error.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Sherry Yang <sherryy@android.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 15:59:17 +01:00
Todd Kjos 7f3dc0088b binder: fix proc->files use-after-free
proc->files cleanup is initiated by binder_vma_close. Therefore
a reference on the binder_proc is not enough to prevent the
files_struct from being released while the binder_proc still has
a reference. This can lead to an attempt to dereference the
stale pointer obtained from proc->files prior to proc->files
cleanup. This has been seen once in task_get_unused_fd_flags()
when __alloc_fd() is called with a stale "files".

The fix is to protect proc->files with a mutex to prevent cleanup
while in use.

Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 15:47:12 +01:00
Greg Kroah-Hartman 2fc1024676 Merge 4.15-rc3 into char-misc-next
We want the fixes and changes in here for testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-11 08:47:41 +01:00
Al Viro afc9a42b74 the rest of drivers/*: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-28 11:06:58 -05:00
Martijn Coenen fb2c445277 ANDROID: binder: fix transaction leak.
If a call to put_user() fails, we failed to
properly free a transaction and send a failed
reply (if necessary).

Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28 16:54:45 +01:00
Martijn Coenen 148ade2c4d ANDROID: binder: Add thread->process_todo flag.
This flag determines whether the thread should currently
process the work in the thread->todo worklist.

The prime usecase for this is improving the performance
of synchronous transactions: all synchronous transactions
post a BR_TRANSACTION_COMPLETE to the calling thread,
but there's no reason to return that command to userspace
right away - userspace anyway needs to wait for the reply.

Likewise, a synchronous transaction that contains a binder
object can cause a BC_ACQUIRE/BC_INCREFS to be returned to
userspace; since the caller must anyway hold a strong/weak
ref for the duration of the call, postponing these commands
until the reply comes in is not a problem.

Note that this flag is not used to determine whether a
thread can handle process work; a thread should never pick
up process work when thread work is still pending.

Before patch:
------------------------------------------------------------------
Benchmark                           Time           CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4          45959 ns      20288 ns      34351
BM_sendVec_binderize/8          45603 ns      20080 ns      34909
BM_sendVec_binderize/16         45528 ns      20113 ns      34863
BM_sendVec_binderize/32         45551 ns      20122 ns      34881
BM_sendVec_binderize/64         45701 ns      20183 ns      34864
BM_sendVec_binderize/128        45824 ns      20250 ns      34576
BM_sendVec_binderize/256        45695 ns      20171 ns      34759
BM_sendVec_binderize/512        45743 ns      20211 ns      34489
BM_sendVec_binderize/1024       46169 ns      20430 ns      34081

After patch:
------------------------------------------------------------------
Benchmark                           Time           CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4          42939 ns      17262 ns      40653
BM_sendVec_binderize/8          42823 ns      17243 ns      40671
BM_sendVec_binderize/16         42898 ns      17243 ns      40594
BM_sendVec_binderize/32         42838 ns      17267 ns      40527
BM_sendVec_binderize/64         42854 ns      17249 ns      40379
BM_sendVec_binderize/128        42881 ns      17288 ns      40427
BM_sendVec_binderize/256        42917 ns      17297 ns      40429
BM_sendVec_binderize/512        43184 ns      17395 ns      40411
BM_sendVec_binderize/1024       43119 ns      17357 ns      40432

Signed-off-by: Martijn Coenen <maco@android.com>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28 16:33:03 +01:00
Martijn Coenen 8d9a3ab6c1 ANDROID: binder: show high watermark of alloc->pages.
Show the high watermark of the index into the alloc->pages
array, to facilitate sizing the buffer on a per-process
basis.

Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28 16:33:03 +01:00