CVS commit: src/sys/arch/amd64/conf

["Maxime Villard" <maxv%netbsd.org@localhost>]

Module Name:    src
Committed By:   maxv
Date:           Tue Nov 14 10:15:40 UTC 2017

Modified Files:
        src/sys/arch/amd64/conf: Makefile.amd64 kern.ldscript.kaslr

Log Message:
Split each kernel section into sub-blocks of approximately 2MB. The newly
created sections are named .origname.i, for example:

        .text -> { .text .text.0 .text.1 .text.2 .text.3 .text.4 }

Each section is randomized independently by the prekern - and in a random
order obviously. As a result we can get intertwined mappings, of the type:

+-------+-----------+------+---------+-----------+-------+-------+------+-
| text1 | NOTMAPPED | bss0 | rodata1 | NOTMAPPED | data2 | text3 | bss1 |
+-------+-----------+------+---------+-----------+-------+-------+------+-

   ---------+-
    rodata0 | ...
   ---------+-

The CTF section is dropped completely, because (a) when split it becomes
enormous for some reason (that I don't quite understand, verily), and (b)
the kernel expects only one CTF and can't handle several of them.


To generate a diff of this commit:
cvs rdiff -u -r1.62 -r1.63 src/sys/arch/amd64/conf/Makefile.amd64
cvs rdiff -u -r1.2 -r1.3 src/sys/arch/amd64/conf/kern.ldscript.kaslr

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.