BACKPORT: FROMGIT: binder: perform page installation outside of locks

Split out the insertion of pages to be outside of the alloc->mutex in a
separate binder_install_buffer_pages() routine. Since this is no longer
serialized, we must look at the full range of pages used by the buffers.
The installation is protected with mmap_sem in write mode since multiple
tasks might race to install the same page.

Besides avoiding unnecessary nested locking this helps in preparation of
switching the alloc->mutex into a spinlock_t in subsequent patches.

Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231201172212.1813387-20-cmllamas@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 254650075
Bug: 320576997
(cherry picked from commit 37ebbb4f
 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git


 char-misc-next)
Change-Id: I7b0684310b8824194d7e4a51a1fd67944f8ec06a
[cmllamas: fixed conflicts due to missing e66b77e5]
Signed-off-by: Carlos Llamas <cmllamas@google.com>