Revert "x86 get_unmapped_area(): use proper mmap base for bottom-up direction"
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 22 Aug 2013 16:13:06 +0000 (09:13 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 29 Aug 2013 16:47:39 +0000 (09:47 -0700)
commitbd4b69c1f7f58fc28fb636a3be006770edf58d68
tree982ae0cb3049d76520cdf6f2f7172dda836fb6cc
parent32b8d5f874e1c6ca88ec4f2d10cd885b3d70cf17
Revert "x86 get_unmapped_area(): use proper mmap base for bottom-up direction"

commit 5ea80f76a56605a190a7ea16846c82aa63dbd0aa upstream.

This reverts commit df54d6fa54275ce59660453e29d1228c2b45a826.

The commit isn't necessarily wrong, but because it recalculates the
random mmap_base every time, it seems to confuse user memory allocators
that expect contiguous mmap allocations even when the mmap address isn't
specified.

In particular, the MATLAB Java runtime seems to be unhappy. See

  https://bugzilla.kernel.org/show_bug.cgi?id=60774

So we'll want to apply the random offset only once, and Radu has a patch
for that.  Revert this older commit in order to apply the other one.

Reported-by: Jeff Shorey <shoreyjeff@gmail.com>
Cc: Radu Caragea <sinaelgl@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kernel/sys_x86_64.c
arch/x86/mm/mmap.c
include/linux/sched.h