Todd Poynor 077f6db973 staging: ashmem: Avoid deadlock between read and mmap calls
Avoid holding ashmem_mutex across code that can page fault.  Page faults
grab the mmap_sem for the process, which are also held by mmap calls
prior to calling ashmem_mmap, which locks ashmem_mutex.  The reversed
order of locking between the two can deadlock.

The calls that can page fault are read() and the ASHMEM_SET_NAME and
ASHMEM_GET_NAME ioctls.  Move the code that accesses userspace pages
outside the ashmem_mutex.

Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[jstultz: minor commit message tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 09:03:16 -08:00
..
2014-02-05 12:02:18 -08:00
2014-01-23 18:36:55 -08:00
2014-02-01 10:29:59 -08:00
2014-02-01 10:29:59 -08:00