kexec loading fails without kernel code address in /proc/iomem

Dave Young dyoung at redhat.com
Thu Apr 14 05:03:21 PDT 2016


Hi, Linus

Zhengyu Zhang <zhezhang at redhat.com> found a kexec failure caused by below commit:

commit c4004b02f8e5b9ce357a0bb1641756cc86962664
Author: Linus Torvalds <torvalds at linux-foundation.org>
Date:   Wed Apr 6 13:45:07 2016 -0700

    x86: remove the kernel code/data/bss resources from /proc/iomem
    
    Let's see if anybody even notices.  I doubt anybody uses this, and it
    does expose addresses that should be randomized, so let's just remove
    the code.  It's old and traditional, and it used to be cute, but we
    should have removed this long ago.
    
    If it turns out anybody notices and this breaks something, we'll have to
    revert this, and maybe we'll end up using other approaches instead
    (using %pK or similar).  But removing unnecessary code is always the
    preferred option.
    
    Noted-by: Emrah Demir <ed at abdsec.com>
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>


Probably we should revert the commit and do it in other way ..

Thanks
Dave



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