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Date: Wed,  4 Oct 2017 14:19:36 -0700
From: Thomas Garnier <thgarnie@...gle.com>
To: Herbert Xu <herbert@...dor.apana.org.au>,
	"David S . Miller" <davem@...emloft.net>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H . Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Josh Poimboeuf <jpoimboe@...hat.com>,
	Thomas Garnier <thgarnie@...gle.com>,
	Arnd Bergmann <arnd@...db.de>,
	Kees Cook <keescook@...omium.org>,
	Matthias Kaehlcke <mka@...omium.org>,
	Tom Lendacky <thomas.lendacky@....com>,
	Andy Lutomirski <luto@...nel.org>,
	"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
	Borislav Petkov <bp@...e.de>,
	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>,
	Pavel Machek <pavel@....cz>,
	Juergen Gross <jgross@...e.com>,
	Chris Wright <chrisw@...s-sol.org>,
	Alok Kataria <akataria@...are.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Tejun Heo <tj@...nel.org>,
	Christoph Lameter <cl@...ux.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Alexey Dobriyan <adobriyan@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Chris Metcalf <cmetcalf@...lanox.com>,
	"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>,
	Borislav Petkov <bp@...en8.de>,
	"Luis R . Rodriguez" <mcgrof@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Christopher Li <sparse@...isli.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Jason Baron <jbaron@...mai.com>,
	Dou Liyang <douly.fnst@...fujitsu.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	Lukas Wunner <lukas@...ner.de>,
	Masahiro Yamada <yamada.masahiro@...ionext.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Markus Trippelsdorf <markus@...ppelsdorf.de>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krčmář <rkrcmar@...hat.com>,
	Joerg Roedel <joro@...tes.org>,
	Rik van Riel <riel@...hat.com>,
	David Howells <dhowells@...hat.com>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Waiman Long <longman@...hat.com>,
	Kyle Huey <me@...ehuey.com>,
	Andrey Ryabinin <aryabinin@...tuozzo.com>,
	Jonathan Corbet <corbet@....net>,
	Matthew Wilcox <mawilcox@...rosoft.com>,
	Michal Hocko <mhocko@...e.com>,
	Peter Foley <pefoley2@...oley.com>,
	Paul Bolle <pebolle@...cali.nl>,
	Jiri Kosina <jkosina@...e.cz>,
	Rob Landley <rob@...dley.net>,
	"H . J . Lu" <hjl.tools@...il.com>,
	Baoquan He <bhe@...hat.com>,
	Jan H . Schönherr <jschoenh@...zon.de>,
	Daniel Micay <danielmicay@...il.com>
Cc: x86@...nel.org,
	linux-crypto@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	virtualization@...ts.linux-foundation.org,
	xen-devel@...ts.xenproject.org,
	linux-arch@...r.kernel.org,
	linux-sparse@...r.kernel.org,
	kvm@...r.kernel.org,
	linux-doc@...r.kernel.org,
	kernel-hardening@...ts.openwall.com
Subject: x86: PIE support and option to extend KASLR randomization

These patches make the changes necessary to build the kernel as Position
Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below
the top 2G of the virtual address space. It allows to optionally extend the
KASLR randomization range from 1G to 3G.

Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler
changes, PIE support and KASLR in general. Thanks to Roland McGrath on his
feedback for using -pie versus --emit-relocs and details on compiler code
generation.

The patches:
 - 1-3, 5-1#, 17-18: Change in assembly code to be PIE compliant.
 - 4: Add a new _ASM_GET_PTR macro to fetch a symbol address generically.
 - 14: Adapt percpu design to work correctly when PIE is enabled.
 - 15: Provide an option to default visibility to hidden except for key symbols.
       It removes errors between compilation units.
 - 16: Adapt relocation tool to handle PIE binary correctly.
 - 19: Add support for global cookie.
 - 20: Support ftrace with PIE (used on Ubuntu config).
 - 21: Fix incorrect address marker on dump_pagetables.
 - 22: Add option to move the module section just after the kernel.
 - 23: Adapt module loading to support PIE with dynamic GOT.
 - 24: Make the GOT read-only.
 - 25: Add the CONFIG_X86_PIE option (off by default).
 - 26: Adapt relocation tool to generate a 64-bit relocation table.
 - 27: Add the CONFIG_RANDOMIZE_BASE_LARGE option to increase relocation range
       from 1G to 3G (off by default).

Performance/Size impact:

Size of vmlinux (Default configuration):
 File size:
 - PIE disabled: +0.000031%
 - PIE enabled: -3.210% (less relocations)
 .text section:
 - PIE disabled: +0.000644%
 - PIE enabled: +0.837%

Size of vmlinux (Ubuntu configuration):
 File size:
 - PIE disabled: -0.201%
 - PIE enabled: -0.082%
 .text section:
 - PIE disabled: same
 - PIE enabled: +1.319%

Size of vmlinux (Default configuration + ORC):
 File size:
 - PIE enabled: -3.167%
 .text section:
 - PIE enabled: +0.814%

Size of vmlinux (Ubuntu configuration + ORC):
 File size:
 - PIE enabled: -3.167%
 .text section:
 - PIE enabled: +1.26%

The size increase is mainly due to not having access to the 32-bit signed
relocation that can be used with mcmodel=kernel. A small part is due to reduced
optimization for PIE code. This bug [1] was opened with gcc to provide a better
code generation for kernel PIE.

Hackbench (50% and 1600% on thread/process for pipe/sockets):
 - PIE disabled: no significant change (avg +0.1% on latest test).
 - PIE enabled: between -0.50% to +0.86% in average (default and Ubuntu config).

slab_test (average of 10 runs):
 - PIE disabled: no significant change (-2% on latest run, likely noise).
 - PIE enabled: between -1% and +0.8% on latest runs.

Kernbench (average of 10 Half and Optimal runs):
 Elapsed Time:
 - PIE disabled: no significant change (avg -0.239%)
 - PIE enabled: average +0.07%
 System Time:
 - PIE disabled: no significant change (avg -0.277%)
 - PIE enabled: average +0.7%

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82303

diffstat:
 Documentation/x86/x86_64/mm.txt              |    3 
 arch/x86/Kconfig                             |   37 ++++
 arch/x86/Makefile                            |   14 +
 arch/x86/boot/boot.h                         |    2 
 arch/x86/boot/compressed/Makefile            |    5 
 arch/x86/boot/compressed/misc.c              |   10 +
 arch/x86/crypto/aes-x86_64-asm_64.S          |   45 +++--
 arch/x86/crypto/aesni-intel_asm.S            |   14 +
 arch/x86/crypto/aesni-intel_avx-x86_64.S     |    6 
 arch/x86/crypto/camellia-aesni-avx-asm_64.S  |   42 ++---
 arch/x86/crypto/camellia-aesni-avx2-asm_64.S |   44 ++---
 arch/x86/crypto/camellia-x86_64-asm_64.S     |    8 -
 arch/x86/crypto/cast5-avx-x86_64-asm_64.S    |   50 +++---
 arch/x86/crypto/cast6-avx-x86_64-asm_64.S    |   44 +++--
 arch/x86/crypto/des3_ede-asm_64.S            |   96 ++++++++----
 arch/x86/crypto/ghash-clmulni-intel_asm.S    |    4 
 arch/x86/crypto/glue_helper-asm-avx.S        |    4 
 arch/x86/crypto/glue_helper-asm-avx2.S       |    6 
 arch/x86/entry/entry_32.S                    |    3 
 arch/x86/entry/entry_64.S                    |   29 ++-
 arch/x86/include/asm/asm.h                   |   13 +
 arch/x86/include/asm/bug.h                   |    2 
 arch/x86/include/asm/ftrace.h                |   23 ++-
 arch/x86/include/asm/jump_label.h            |    8 -
 arch/x86/include/asm/kvm_host.h              |    6 
 arch/x86/include/asm/module.h                |   14 +
 arch/x86/include/asm/page_64_types.h         |    9 +
 arch/x86/include/asm/paravirt_types.h        |   12 +
 arch/x86/include/asm/percpu.h                |   25 ++-
 arch/x86/include/asm/pgtable_64_types.h      |    6 
 arch/x86/include/asm/pm-trace.h              |    2 
 arch/x86/include/asm/processor.h             |   12 +
 arch/x86/include/asm/sections.h              |    4 
 arch/x86/include/asm/setup.h                 |    2 
 arch/x86/include/asm/stackprotector.h        |   19 +-
 arch/x86/kernel/acpi/wakeup_64.S             |   31 ++--
 arch/x86/kernel/asm-offsets.c                |    3 
 arch/x86/kernel/asm-offsets_32.c             |    3 
 arch/x86/kernel/asm-offsets_64.c             |    3 
 arch/x86/kernel/cpu/common.c                 |    7 
 arch/x86/kernel/cpu/microcode/core.c         |    4 
 arch/x86/kernel/ftrace.c                     |  168 ++++++++++++++--------
 arch/x86/kernel/head64.c                     |   32 +++-
 arch/x86/kernel/head_32.S                    |    3 
 arch/x86/kernel/head_64.S                    |   41 ++++-
 arch/x86/kernel/kvm.c                        |    6 
 arch/x86/kernel/module.c                     |  204 ++++++++++++++++++++++++++-
 arch/x86/kernel/module.lds                   |    3 
 arch/x86/kernel/process.c                    |    5 
 arch/x86/kernel/relocate_kernel_64.S         |    8 -
 arch/x86/kernel/setup_percpu.c               |    2 
 arch/x86/kernel/vmlinux.lds.S                |   13 +
 arch/x86/kvm/svm.c                           |    4 
 arch/x86/lib/cmpxchg16b_emu.S                |    8 -
 arch/x86/mm/dump_pagetables.c                |   11 -
 arch/x86/power/hibernate_asm_64.S            |    4 
 arch/x86/tools/relocs.c                      |  170 ++++++++++++++++++++--
 arch/x86/tools/relocs.h                      |    4 
 arch/x86/tools/relocs_common.c               |   15 +
 arch/x86/xen/xen-asm.S                       |   12 -
 arch/x86/xen/xen-head.S                      |    9 -
 arch/x86/xen/xen-pvh.S                       |   13 +
 drivers/base/firmware_class.c                |    4 
 include/asm-generic/sections.h               |    6 
 include/asm-generic/vmlinux.lds.h            |   12 +
 include/linux/compiler.h                     |    8 +
 init/Kconfig                                 |    9 +
 kernel/kallsyms.c                            |   16 +-
 kernel/trace/trace.h                         |    4 
 lib/dynamic_debug.c                          |    4 
 70 files changed, 1109 insertions(+), 363 deletions(-)

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