tree 8e8b3935f044b34a4d7fe6e5151d131388632f5c
parent a569eb4925e16378b6470185516dc676c47a6618
author dcashman <dcashman@google.com> 1451427879 -0800
committer Kees Cook <keescook@google.com> 1458856899 -0700

FROMLIST: mm: mmap: Add new /proc tunable for mmap_base ASLR.

(cherry picked from commit https://lkml.org/lkml/2015/12/21/337)

ASLR  only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such
a way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.

Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>

Bug: 27796957
Patchset: ASLR sysctl

Change-Id: Iaf2c4ca27146a7d9ed03f34aefab82cd0735368e
Signed-off-by: Kees Cook <keescook@google.com>