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Message-Id: <20170718223333.110371-1-thgarnie@google.com>
Date: Tue, 18 Jul 2017 15:33:11 -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>,
Matthias Kaehlcke <mka@...omium.org>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>,
Juergen Gross <jgross@...e.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Radim Krčmář <rkrcmar@...hat.com>,
Joerg Roedel <joro@...tes.org>,
Andy Lutomirski <luto@...nel.org>,
Borislav Petkov <bp@...en8.de>,
"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
Brian Gerst <brgerst@...il.com>,
Borislav Petkov <bp@...e.de>,
Christian Borntraeger <borntraeger@...ibm.com>,
"Rafael J . Wysocki" <rjw@...ysocki.net>,
Len Brown <len.brown@...el.com>,
Pavel Machek <pavel@....cz>,
Tejun Heo <tj@...nel.org>,
Christoph Lameter <cl@...ux.com>,
Kees Cook <keescook@...omium.org>,
Paul Gortmaker <paul.gortmaker@...driver.com>,
Chris Metcalf <cmetcalf@...lanox.com>,
"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Christopher Li <sparse@...isli.org>,
Dou Liyang <douly.fnst@...fujitsu.com>,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
Daniel Borkmann <daniel@...earbox.net>,
Markus Trippelsdorf <markus@...ppelsdorf.de>,
Peter Foley <pefoley2@...oley.com>,
Steven Rostedt <rostedt@...dmis.org>,
Tim Chen <tim.c.chen@...ux.intel.com>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Catalin Marinas <catalin.marinas@....com>,
Matthew Wilcox <mawilcox@...rosoft.com>,
Michal Hocko <mhocko@...e.com>,
Rob Landley <rob@...dley.net>,
Jiri Kosina <jkosina@...e.cz>,
"H . J . Lu" <hjl.tools@...il.com>,
Paul Bolle <pebolle@...cali.nl>,
Baoquan He <bhe@...hat.com>,
Daniel Micay <danielmicay@...il.com>
Cc: x86@...nel.org,
linux-crypto@...r.kernel.org,
linux-kernel@...r.kernel.org,
xen-devel@...ts.xenproject.org,
kvm@...r.kernel.org,
linux-pm@...r.kernel.org,
linux-arch@...r.kernel.org,
linux-sparse@...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.
The patches:
- 1-3, 5-15: Change in assembly code to be PIE compliant.
- 4: Add a new _ASM_GET_PTR macro to fetch a symbol address generically.
- 16: Adapt percpu design to work correctly when PIE is enabled.
- 17: Provide an option to default visibility to hidden except for key symbols.
It removes errors between compilation units.
- 18: Adapt relocation tool to handle PIE binary correctly.
- 19: Add the CONFIG_X86_PIE option (off by default)
- 20: Adapt relocation tool to generate a 64-bit relocation table.
- 21: Add options to build modules as mcmodel=large and dynamically create a
PLT for relative references out of range (adapted from arm64).
- 22: Add the CONFIG_RANDOMIZE_BASE_LARGE option to increase relocation range
from 1G to 3G (off by default).
Performance/Size impact:
Hackbench (50% and 1600% loads):
- PIE disabled: no significant change (-0.50% / +0.50%)
- PIE enabled: 7% to 8% on half load, 10% on heavy load.
These results are aligned with the different research on user-mode PIE
impact on cpu intensive benchmarks (around 10% on x86_64).
slab_test (average of 10 runs):
- PIE disabled: no significant change (-1% / +1%)
- PIE enabled: 3% to 4%
Kernbench (average of 10 Half and Optimal runs):
Elapsed Time:
- PIE disabled: no significant change (-0.22% / +0.06%)
- PIE enabled: around 0.50%
System Time:
- PIE disabled: no significant change (-0.99% / -1.28%)
- PIE enabled: 5% to 6%
Size of vmlinux (Ubuntu configuration):
File size:
- PIE disabled: 472928672 bytes (-0.000169% from baseline)
- PIE enabled: 216878461 bytes (-54.14% from baseline)
.text sections:
- PIE disabled: 9373572 bytes (+0.04% from baseline)
- PIE enabled: 9499138 bytes (+1.38% from baseline)
The big decrease in vmlinux file size is due to the lower number of
relocations appended to the file.
diffstat:
arch/x86/Kconfig | 37 +++++
arch/x86/Makefile | 17 ++
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_64.S | 26 ++-
arch/x86/include/asm/asm.h | 13 +
arch/x86/include/asm/bug.h | 2
arch/x86/include/asm/jump_label.h | 8 -
arch/x86/include/asm/kvm_host.h | 6
arch/x86/include/asm/module.h | 16 ++
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/pm-trace.h | 2
arch/x86/include/asm/processor.h | 8 -
arch/x86/include/asm/setup.h | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/acpi/wakeup_64.S | 31 ++--
arch/x86/kernel/cpu/common.c | 4
arch/x86/kernel/head64.c | 28 +++
arch/x86/kernel/head_64.S | 47 +++++-
arch/x86/kernel/kvm.c | 6
arch/x86/kernel/module-plts.c | 198 +++++++++++++++++++++++++++
arch/x86/kernel/module.c | 18 +-
arch/x86/kernel/module.lds | 4
arch/x86/kernel/relocate_kernel_64.S | 2
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/power/hibernate_asm_64.S | 4
arch/x86/tools/relocs.c | 134 +++++++++++++++---
arch/x86/tools/relocs.h | 4
arch/x86/tools/relocs_common.c | 15 +-
arch/x86/xen/xen-asm.S | 12 -
arch/x86/xen/xen-asm.h | 3
arch/x86/xen/xen-head.S | 9 -
include/asm-generic/sections.h | 6
include/linux/compiler.h | 8 +
init/Kconfig | 9 +
kernel/kallsyms.c | 16 +-
54 files changed, 868 insertions(+), 282 deletions(-)
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