Staging: android: binder: Allow using highmem for binder buffers

The default kernel mapping for the pages allocated for the binder
buffers is never used. Set the __GFP_HIGHMEM flag when allocating
these pages so we don't needlessly use low memory pages that may
be required elsewhere.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: Fix two checkpatch issues in binder.c

This fixes two instances of
"static const char * array should probably be static const char * const"

I have seen other commits doing this in other files, so I am
assuming it should be done here as well.

Please tell me if this is wrong :)

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[neo: actually there are three]
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
binder: search for receiving context pid in global namespace

If binder cannot find the receiving task in the sender's namespace it
will default to a null PID which thus breaks communication in our
container-based scenario. This patch extends binder to first look in the
senders namespace and if unsuccesfull search in the global namespace.

Signed-off-by: Ricardo Mendoza <ricardo.mendoza@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
binder: NULL pointer reference

This fix handles a possible NULL pointer reference in
debug message.

Signed-off-by: Paresh Nakhe <pnakhe@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Staging: android: binder: Add some tracepoints

Add tracepoints:
- ioctl entry and exit
- Main binder lock: lock, locked and unlock
- Command and return buffer opcodes
- Transaction: create and receive
- Transaction buffer: create and free
- Object and file descriptor transfer
- binder_update_page_range

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
drivers: staging: android: binder.c: fix printk macros

Change printk() messages to pr_* macros.

Signed-off-by: Sherwin Soltani <sherwin@wybc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Staging: android: binder: Remove an inconsequential conditional macro

Removes an inconsequential conditional macro.

Cc: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
new helper: iterate_fd()

iterates through the opened files in given descriptor table,
calling a supplied function; we stop once non-zero is returned.
Callback gets struct file *, descriptor number and const void *
argument passed to iterator.  It is called with files->file_lock
held, so it is not allowed to block.

tty_io, netprio_cgroup and selinux flush_unauthorized_files()
converted to its use.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
make get_unused_fd_flags() a function

... and get_unused_fd() a macro around it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
take rlimit check to callers of expand_files()

... except for one in android, where the check is different
and already done in caller.  No need to recalculate rlimit
many times in alloc_fd() either.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mm: correctly synchronize rss-counters at exit/exec

do_exit() and exec_mmap() call sync_mm_rss() before mm_release() does
put_user(clear_child_tid) which can update task->rss_stat and thus make
mm->rss_stat inconsistent.  This triggers the "BUG:" printk in check_mm().

Let's fix this bug in the safest way, and optimize/cleanup this later.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
posix_types.h: Cleanup stale __NFDBITS and related definitions

Recently, glibc made a change to suppress sign-conversion warnings in
FD_SET (glibc commit ceb9e56b3d1).  This uncovered an issue with the
kernel's definition of __NFDBITS if applications #include
<linux/types.h> after including <sys/select.h>.  A build failure would
be seen when passing the -Werror=sign-compare and -D_FORTIFY_SOURCE=2
flags to gcc.

It was suggested that the kernel should either match the glibc
definition of __NFDBITS or remove that entirely.  The current in-kernel
uses of __NFDBITS can be replaced with BITS_PER_LONG, and there are no
uses of the related __FDELT and __FDMASK defines.  Given that, we'll
continue the cleanup that was started with commit 8b3d1cda4f5f
("posix_types: Remove fd_set macros") and drop the remaining unused
macros.

Additionally, linux/time.h has similar macros defined that expand to
nothing so we'll remove those at the same time.

Reported-by: Jeff Law <law@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
[ .. and fix up whitespace as per akpm ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
wait: fix reparent_leader() vs EXIT_DEAD->EXIT_ZOMBIE race

wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and
drops tasklist_lock.  If this task is not the natural child and it is
traced, we change its state back to EXIT_ZOMBIE for ->real_parent.

The last transition is racy, this is even documented in 50b8d257486a
"ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE
race".  wait_consider_task() tries to detect this transition and clear
->notask_error but we can't rely on ptrace_reparented(), debugger can
exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE.

And there is another problem which were missed before: this transition
can also race with reparent_leader() which doesn't reset >exit_signal if
EXIT_DEAD, assuming that this task must be reaped by someone else.  So
the tracee can be re-parented with ->exit_signal != SIGCHLD, and if
/sbin/init doesn't use __WALL it becomes unreapable.

Change reparent_leader() to update ->exit_signal even if EXIT_DEAD.
Note: this is the simple temporary hack for -stable, it doesn't try to
solve all problems, it will be reverted by the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Reported-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Michal Schmidt <mschmidt@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Staging: android: binder: Make task_get_unused_fd_flags function static

Silence the following warning:
drivers/staging/android/binder.c:368:5: warning:
symbol 'task_get_unused_fd_flags' was not declared. Should it be static?

Cc: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
binder: don't allow mmap() by process other than proc->tsk

we really shouldn't do get_files_struct() on a different process
and use it to modify the sucker later on.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
new helper: __alloc_fd()

Essentially, alloc_fd() in a files_struct we own a reference to.
Most of the time wanting to use it is a sign of lousy API
design (such as android/binder).  It's *not* a general-purpose
interface; better that than open-coding its guts, but again,
playing with other process' descriptor table is a sign of bad
design.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
move files_struct-related bits from kernel/exit.c to fs/file.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
don't bother with call_rcu() in put_files_struct()

At that point nobody can see us anyway; everything that
looks at files_fdtable(files) is separated from the
guts of put_files_struct(files) - either since files is
current->files or because we fetched it under task_lock()
and hadn't dropped that yet, or because we'd bumped
files->count while holding task_lock()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
trim free_fdtable_rcu()

embedded case isn't hit anymore

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
move put_unused_fd() and fd_install() to fs/file.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>