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>
Don't access next->data in kernel debug message when the
next buffer is null.
Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use binder_alloc struct's mm_struct rather than getting
a reference to the mm struct through get_task_mm to
avoid a potential deadlock between lru lock, task lock and
dentry lock, since a thread can be holding the task lock
and the dentry lock while trying to acquire the lru lock.
Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because we're not guaranteed that subsequent calls
to poll() will have a poll_table_struct parameter
with _qproc set. When _qproc is not set, poll_wait()
is a noop, and we won't be woken up correctly.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are 4 patches to resolve some char/misc driver issues found these
past weeks.
One of them is a mei bugfix and another is a new mei device id. There
is also a hyper-v fix for a reported issue, and a binder issue fix for a
problem reported by a few people.
All of these have been in my tree for a while, I don't know if
linux-next is really testing much this month. But 0-day is happy with
them :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWeNCTw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykNOQCgzskhoji+7Fsl+xc3SX/3ntJwoecAnAz5xQIA
grpH4IOHq/0aPbQj8g3Y
=F3xc
-----END PGP SIGNATURE-----
Merge tag 'char-misc-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are 4 patches to resolve some char/misc driver issues found these
past weeks.
One of them is a mei bugfix and another is a new mei device id. There
is also a hyper-v fix for a reported issue, and a binder issue fix for
a problem reported by a few people.
All of these have been in my tree for a while, I don't know if
linux-next is really testing much this month. But 0-day is happy with
them :)"
* tag 'char-misc-4.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
binder: fix use-after-free in binder_transaction()
Drivers: hv: vmbus: Fix bugs in rescind handling
mei: me: add gemini lake devices id
mei: always use domain runtime pm callbacks.
User-space normally keeps the node alive when creating a transaction
since it has a reference to the target. The local strong ref keeps it
alive if the sending process dies before the target process processes
the transaction. If the source process is malicious or has a reference
counting bug, this can fail.
In this case, when we attempt to decrement the node in the failure
path, the node has already been freed.
This is fixed by taking a tmpref on the node while constructing
the transaction. To avoid re-acquiring the node lock and inner
proc lock to increment the proc's tmpref, a helper is used that
does the ref increments on both the node and proc.
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop the global lru lock in isolate callback before calling
zap_page_range which calls cond_resched, and re-acquire the global lru
lock before returning. Also change return code to LRU_REMOVED_RETRY.
Use mmput_async when fail to acquire mmap sem in an atomic context.
Fix "BUG: sleeping function called from invalid context"
errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled.
Also restore mmput_async, which was initially introduced in commit
ec8d7c14ea ("mm, oom_reaper: do not mmput synchronously from the oom
reaper context"), and was removed in commit 2129258024 ("mm: oom: let
oom_reap_task and exit_mmap run concurrently").
Link: http://lkml.kernel.org/r/20170914182231.90908-1-sherryy@android.com
Fixes: f2517eb76f ("android: binder: Add global lru shrinker to binder")
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Kyle Yan <kyan@codeaurora.org>
Acked-by: Arve Hjønnevåg <arve@android.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Martijn Coenen <maco@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Riley Andrews <riandrews@android.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hoeun Ryu <hoeun.ryu@gmail.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 7a4408c6bd ("binder: make sure accesses to proc/thread are
safe") made a change to enqueue tcomplete to thread->todo before
enqueuing the transaction. However, in err_dead_proc_or_thread case,
the tcomplete is directly freed, without dequeued. It may cause the
thread->todo list to be corrupted.
So, dequeue it before freeing.
Fixes: 7a4408c6bd ("binder: make sure accesses to proc/thread are safe")
Signed-off-by: Xu YiPing <xuyiping@hisilicon.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 372e3147df ("binder: guarantee txn complete / errors delivered
in-order") incorrectly defined a local ret value. This ret value will
be invalid when out of the if block
Fixes: 372e3147df ("binder: refactor binder ref inc/dec for thread safety")
Signed-off-by: Xu YiPing <xuyiping@hislicon.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allowing binder to expose the 64-bit API on 32-bit kernels caused a
build warning:
drivers/android/binder.c: In function 'binder_transaction_buffer_release':
drivers/android/binder.c:2220:15: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
fd_array = (u32 *)(parent_buffer + fda->parent_offset);
^
drivers/android/binder.c: In function 'binder_translate_fd_array':
drivers/android/binder.c:2445:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
fd_array = (u32 *)(parent_buffer + fda->parent_offset);
^
drivers/android/binder.c: In function 'binder_fixup_parent':
drivers/android/binder.c:2511:18: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
This adds extra type casts to avoid the warning.
However, there is another problem with the Kconfig option: turning
it on or off creates two incompatible ABI versions, a kernel that
has this enabled cannot run user space that was built without it
or vice versa. A better solution might be to leave the option hidden
until the binder code is fixed to deal with both ABI versions.
Fixes: e8d2ed7db7 ("Revert "staging: Fix build issues with new binder API"")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
It was never used since addition of binder to linux mainstream tree.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Arve Hjønnevåg" <arve@android.com>
Cc: Riley Andrews <riandrews@android.com>
Cc: devel@driverdev.osuosl.org
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
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>
proc->threads will need to be accessed with higher
locks of other processes held so use proc->inner_lock
to protect it. proc->tmp_ref now needs to be protected
by proc->inner_lock.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When locks for binder_ref handling are added, proc->nodes
will need to be modified while holding the outer lock
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
node->node_lock is used to protect elements of node. No
need to acquire for fields that are invariant: debug_id,
ptr, cookie.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The todo lists in the proc, thread, and node structures
are accessed by other procs/threads to place work
items on the queue.
The todo lists are protected by the new proc->inner_lock.
No locks should ever be nested under these locks. As the
name suggests, an outer lock will be introduced in
a later patch.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For correct behavior we need to hold the inner lock when
dequeuing and processing node work in binder_thread_read.
We now hold the inner lock when we enter the switch statement
and release it after processing anything that might be
affected by other threads.
We also need to hold the inner lock to protect the node
weak/strong ref tracking fields as long as node->proc
is non-NULL (if it is NULL then we are guaranteed that
we don't have any node work queued).
This means that other functions that manipulate these fields
must hold the inner lock. Refactored these functions to use
the inner lock.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are 3 main spinlocks which must be acquired in this
order:
1) proc->outer_lock : protects most fields of binder_proc,
binder_thread, and binder_ref structures. binder_proc_lock()
and binder_proc_unlock() are used to acq/rel.
2) node->lock : protects most fields of binder_node.
binder_node_lock() and binder_node_unlock() are
used to acq/rel
3) proc->inner_lock : protects the thread and node lists
(proc->threads, proc->nodes) and all todo lists associated
with the binder_proc (proc->todo, thread->todo,
proc->delivered_death and node->async_todo).
binder_inner_proc_lock() and binder_inner_proc_unlock()
are used to acq/rel
Any lock under procA must never be nested under any lock at the same
level or below on procB.
Functions that require a lock held on entry indicate which lock
in the suffix of the function name:
foo_olocked() : requires node->outer_lock
foo_nlocked() : requires node->lock
foo_ilocked() : requires proc->inner_lock
foo_iolocked(): requires proc->outer_lock and proc->inner_lock
foo_nilocked(): requires node->lock and proc->inner_lock
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When obtaining a node via binder_get_node(),
binder_get_node_from_ref() or binder_new_node(),
increment node->tmp_refs to take a
temporary reference on the node to ensure the node
persists while being used. binder_put_node() must
be called to remove the temporary reference.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Once locks are added, binder_ref's will only be accessed
safely with the proc lock held. Refactor the inc/dec paths
to make them atomic with the binder_get_ref* paths and
node inc/dec. For example, instead of:
ref = binder_get_ref(proc, handle, strong);
...
binder_dec_ref(ref, strong);
we now have:
ret = binder_dec_ref_for_handle(proc, handle, strong, &rdata);
Since the actual ref is no longer exposed to callers, a
new struct binder_ref_data is introduced which can be used
to return a copy of ref state.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
binder_thread and binder_proc may be accessed by other
threads when processing transaction. Therefore they
must be prevented from being freed while a transaction
is in progress that references them.
This is done by introducing a temporary reference
counter for threads and procs that indicates that the
object is in use and must not be freed. binder_thread_dec_tmpref()
and binder_proc_dec_tmpref() are used to decrement
the temporary reference.
It is safe to free a binder_thread if there
is no reference and it has been released
(indicated by thread->is_dead).
It is safe to free a binder_proc if it has no
remaining threads and no reference.
A spinlock is added to the binder_transaction
to safely access and set references for t->from
and for debug code to safely access t->to_thread
and t->to_proc.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When initiating a transaction, the target_node must
have a strong ref on it. Then we take a second
strong ref to make sure the node survives until the
transaction is complete.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since errors are tracked in the return_error/return_error2
fields of the binder_thread object and BR_TRANSACTION_COMPLETEs
can be tracked either in those fields or via the thread todo
work list, it is possible for errors to be reported ahead
of the associated txn complete.
Use the thread todo work list for errors to guarantee
order. Also changed binder_send_failed_reply to pop
the transaction even if it failed to send a reply.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
binder_pop_transaction needs to be split into 2 pieces to
to allow the proc lock to be held on entry to dequeue the
transaction stack, but no lock when kfree'ing the transaction.
Split into binder_pop_transaction_locked and binder_free_transaction
(the actual locks are still to be added).
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The log->next index for the transaction log was
not protected when incremented. This led to a
case where log->next++ resulted in an index
larger than ARRAY_SIZE(log->entry) and eventually
a bad access to memory.
Fixed by making the log index an atomic64 and
converting to an array by using "% ARRAY_SIZE(log->entry)"
Also added "complete" field to the log entry which is
written last to tell the print code whether the
entry is complete
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Display information about allocated/free space whenever
binder buffer allocation fails on synchronous
transactions.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Siqi Lin <siqilin@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds protection against malicious user code freeing
the same buffer at the same time which could cause
a crash. Cannot happen under normal use.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
