• Linus Torvalds's avatar
    Revert "mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default" · 14d7c92f
    Linus Torvalds authored
    This reverts commit 3afb76a6.
    
    This was a wrongheaded workaround for an issue that had already been
    fixed much better by commit 4ef9ad19 ("mm: huge_memory: don't force
    huge page alignment on 32 bit").
    
    Asking users questions at kernel compile time that they can't make sense
    of is not a viable strategy.  And the fact that even the kernel VM
    maintainers apparently didn't catch that this "fix" is not a fix any
    more pretty much proves the point that people can't be expected to
    understand the implications of the question.
    
    It may well be the case that we could improve things further, and that
    __thp_get_unmapped_area() should take the mapping randomization into
    account even for 64-bit kernels.  Maybe we should not be so eager to use
    THP mappings.
    
    But in no case should this be a kernel config option.
    
    Cc: Rafael Aquini <aquini@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Jiri Slaby <jirislaby@kernel.org>
    Cc: Suren Baghdasaryan <surenb@google.com>
    Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    14d7c92f
Kconfig 49 KB