This can cause issues with processes using the poll()
interface:
1) client sends two oneway transactions
2) the second one gets queued on async_todo
(because the server didn't handle the first one
yet)
3) server returns from poll(), picks up the
first transaction and does transaction work
4) server is done with the transaction, sends
BC_FREE_BUFFER, and the second transaction gets
moved to thread->todo
5) libbinder's handlePolledCommands() only handles
the commands in the current data buffer, so
doesn't see the new transaction
6) the server continues running and issues a new
outgoing transaction. Now, it suddenly finds
the incoming oneway transaction on its thread
todo, and returns that to userspace.
7) userspace does not expect this to happen; it
may be holding a lock while making the outgoing
transaction, and if handling the incoming
trasnaction requires taking the same lock,
userspace will deadlock.
By queueing the async transaction to the proc
workqueue, we make sure it's only picked up when
a thread is ready for proc work.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows userspace to request death notifications without
having to worry about getting an immediate callback on the same
thread; one scenario where this would be problematic is if the
death recipient handler grabs a lock that was already taken
earlier (eg as part of a nested transaction).
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because is_spin_locked() always returns false on UP
systems.
Use assert_spin_locked() instead, and remove the
WARN_ON() instances, since those were easy to verify.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The BINDER_GET_NODE_DEBUG_INFO ioctl will return debug info on
a node. Each successive call reusing the previous return value
will return the next node. The data will be used by
libmemunreachable to mark the pointers with kernel references
as reachable.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of pushing new transactions to the process
waitqueue, select a thread that is waiting on proc
work to handle the transaction. This will make it
easier to improve priority inheritance in future
patches, by setting the priority before we wake up
a thread.
If we can't find a waiting thread, submit the work
to the proc waitqueue instead as we did previously.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removes the process waitqueue, so that threads
can only wait on the thread waitqueue. Whenever
there is process work to do, pick a thread and
wake it up. Having the caller pick a thread is
helpful for things like priority inheritance.
This also fixes an issue with using epoll(),
since we no longer have to block on different
waitqueues.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the number of active, lru, and free pages for
each binder process in binder stats
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix crash introduced by 74310e06be
(android: binder: Move buffer out of area shared with user space)
when close is called after open without mmap in between.
Reported-by: kernel test robot <fengguang.wu@intel.com>
Fixes: 74310e06be ("android: binder: Move buffer out of area shared with user space")
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add tracepoints in binder transaction allocator to
record lru hits and alloc/free page.
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hold on to the pages allocated and mapped for transaction
buffers until the system is under memory pressure. When
that happens, use linux shrinker to free pages. Without
using shrinker, patch "android: binder: Move buffer out
of area shared with user space" will cause a significant
slow down for small transactions that fit into the first
page because free list buffer header used to be inlined
with buffer data.
In addition to prevent the performance regression for
small transactions, this patch improves the performance
for transactions that take up more than one page.
Modify alloc selftest to work with the shrinker change.
Test: Run memory intensive applications (Chrome and Camera)
to trigger shrinker callbacks. Binder frees memory as expected.
Test: Run binderThroughputTest with high memory pressure
option enabled.
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Binder driver allocates buffer meta data in a region that is mapped
in user space. These meta data contain pointers in the kernel.
This patch allocates buffer meta data on the kernel heap that is
not mapped in user space, and uses a pointer to refer to the data mapped.
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Use helper functions buffer_next and buffer_prev instead
of list_entry to get the next and previous buffers.
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit d0bdff0db8 ("staging: Fix build issues with new
binder API"), because commit e38361d032 ("ARM: 8091/2: add get_user()
support for 8 byte types") has added the 64bit __get_user_asm_*
implementation.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 26549d1774 ("binder: guarantee txn complete / errors delivered
in-order") passed the locally declared and undefined cmd
to binder_stat_br() which results in a bogus cmd field in a trace
event and BR stats are incremented incorrectly.
Change to use e->cmd which has been initialized.
Signed-off-by: Todd Kjos <tkjos@google.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 26549d1774 ("binder: guarantee txn complete / errors delivered in-order")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On binder_init() the devices string is duplicated and smashed into individual
device names which are passed along. However, the original duplicated string
wasn't freed in case binder_init() failed. Let's free it on error.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use rlimit() helper instead of manually writing whole
chain from current task to rlim_cur
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A race existed where one thread could register
a death notification for a node, while another
thread was cleaning up that node and sending
out death notifications for its references,
causing simultaneous access to ref->death
because different locks were held.
Signed-off-by: Martijn Coenen <maco@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When printing transactions there were several race conditions
that could cause a stale pointer to be deferenced. Fixed by
reading the pointer once and using it if valid (which is
safe). The transaction buffer also needed protection via proc
lock, so it is only printed if we are holding the correct lock.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use proc->outer_lock to protect the binder_ref structure.
The outer lock allows functions operating on the binder_ref
to do nested acquires of node and inner locks as necessary
to attach refs to nodes atomically.
Binder refs must never be accesssed without holding the
outer lock.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the inner lock to protect thread accounting fields in
proc structure: max_threads, requested_threads,
requested_threads_started and ready_threads.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This makes future changes to priority inheritance
easier, since we want to be able to look at a thread's
transaction stack when selecting a thread to inherit
priority for.
It also allows us to take just a single lock in a
few paths, where we used to take two in succession.
Signed-off-by: Martijn Coenen <maco@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Martijn Coenen
Colin Cross
Sherry Yang
Jisheng Zhang
Todd Kjos
Christian Brauner
Dmitry Safonov
Krzysztof Opasiak
Martijn Coenen