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Jonathan T. Looney beb2406556 amd64: Protect the kernel text, data, and BSS by setting the RW/NX bits
correctly for the data contained on each memory page.

There are several components to this change:
 * Add a variable to indicate the start of the R/W portion of the
   initial memory.
 * Stop detecting NX bit support for each AP.  Instead, use the value
   from the BSP and, if supported, activate the feature on the other
   APs just before loading the correct page table.  (Functionally, we
   already assume that the BSP and all APs had the same support or
   lack of support for the NX bit.)
 * Set the RW and NX bits correctly for the kernel text, data, and
   BSS (subject to some caveats below).
 * Ensure DDB can write to memory when necessary (such as to set a
   breakpoint).
 * Ensure GDB can write to memory when necessary (such as to set a
   breakpoint).  For this purpose, add new MD functions gdb_begin_write()
   and gdb_end_write() which the GDB support code can call before and
   after writing to memory.

This change is not comprehensive:
 * It doesn't do anything to protect modules.
 * It doesn't do anything for kernel memory allocated after the kernel
   starts running.
 * In order to avoid excessive memory inefficiency, it may let multiple
   types of data share a 2M page, and assigns the most permissions
   needed for data on that page.

Reviewed by:	jhb, kib
Discussed with:	emaste
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D14282
2018-03-06 14:28:37 +00:00
bin chflags: Add -x option to not traverse mount points. 2018-03-05 01:56:07 +00:00
cddl ZFS: fix adding vdevs to very large pools 2018-03-02 21:26:48 +00:00
contrib Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to 2018-03-04 17:06:37 +00:00
crypto Add declaration of SSL_get_selected_srtp_profile() for OpenSSL. 2018-01-25 23:38:05 +00:00
etc rc.d/jail: avoid misinterpreting expr arguments 2018-02-28 17:20:10 +00:00
gnu When lld is ld, install bfd's man page as ld.bfd.1 2018-03-04 01:37:49 +00:00
include Vendor import of clang 6.0.0 release r326565: 2018-03-04 15:06:36 +00:00
kerberos5 various: general adoption of SPDX licensing ID tags. 2017-11-27 15:37:16 +00:00
lib Move softfloat symbol map entries to softfloat/Symbol.map. 2018-03-05 20:51:23 +00:00
libexec rpc.sprayd: raise WARNS to 6 2018-03-05 16:11:07 +00:00
release Bump the size of virtual machine disk images from 20G to 30G, 2018-02-26 19:26:59 +00:00
rescue Avoid referencing private lib names directly. 2017-11-10 07:53:02 +00:00
sbin Clarify and clean up some language, and add an explicit example. 2018-03-02 19:07:32 +00:00
secure Remove c_rehash(1) to not confuse users. We do not install the Perl script. 2018-02-08 19:55:03 +00:00
share Mention that CTLFLAG_MPSAFE is only for _PROC entries. 2018-03-04 06:19:41 +00:00
stand lualoader: Use FILESDIR instead of BINDIR 2018-03-05 01:18:32 +00:00
sys amd64: Protect the kernel text, data, and BSS by setting the RW/NX bits 2018-03-06 14:28:37 +00:00
targets Remove libreadline from the source tree, all consumers but gdb 2018-02-06 12:22:42 +00:00
tests Add tests for lagg(4) and other cloned network interfaces 2018-02-23 18:18:42 +00:00
tools Add --globals printc to lua-lint 2018-03-02 16:51:43 +00:00
usr.bin Fix build post r330299 2018-03-02 23:31:55 +00:00
usr.sbin spray: fix the spelling in an output string 2018-03-05 16:13:29 +00:00
.arcconfig callsign isn't required anymore 2016-09-29 06:19:45 +00:00
.arclint arc lint: ignore /tests/ in chmod 2017-12-19 03:38:06 +00:00
.gitattributes .git*: add gitattributes and gitignore 2017-12-25 21:07:54 +00:00
.gitignore .git*: add gitattributes and gitignore 2017-12-25 21:07:54 +00:00
COPYRIGHT Happy New Year 2018 my friends! 2017-12-31 16:48:04 +00:00
LOCKS Explicitly require Security Officer's approval for kernel PRNG bits. 2013-09-17 14:19:05 +00:00
MAINTAINERS MAINTAINERS: add myself for Allwinner and 64bits RockChip 2018-02-26 21:50:13 +00:00
Makefile Don't read SRC_ENV_CONF for MAKEOBJDIRPREFIX guard. 2018-03-03 23:23:23 +00:00
Makefile.inc1 Improve wording of error message when CROSS_TOOLCHAIN is not found. 2018-02-26 19:02:11 +00:00
Makefile.libcompat X_COMPILER_* may not be defined. 2018-01-24 18:08:37 +00:00
Makefile.sys.inc AUTO_OBJ: For all top-level targets enforce using an OBJDIR. 2017-12-05 21:29:47 +00:00
ObsoleteFiles.inc Move devmatch to sbin from usr/sbin. 2018-02-12 14:44:21 +00:00
README Document the sys/boot -> stand move in hier.7 and the top-level README. 2017-12-03 20:36:36 +00:00
README.md Fix README.md formatting. 2018-03-02 14:42:08 +00:00
UPDATING Add Lua as a scripting langauge to /boot/loader 2018-02-12 15:31:53 +00:00

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