From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching
Date: Fri, 2 Sep 2016 16:02:06 +0100 [thread overview]
Message-ID: <1472828533-28197-1-git-send-email-catalin.marinas@arm.com> (raw)
This is the second version of the arm64 PAN emulation by disabling
TTBR0_EL1 accesses. The major change from v1 is the use of a thread_info
member to store the real TTBR0_EL1 value. The advantage is slightly
simpler assembler macros for uaccess_enable with the downside that
switch_mm() must always update the saved ttbr0 even if there is no mm
switch.
Whether we could simplify these patches further to use some TCR_EL1.EPD0
tricks remains to be confirmed with the ARM architects. However, it is
unlikely that they would deem such idea architecturally safe, hence this
series only switches TTBR0_EL1 in accordance with the ARM ARM.
Changes since v1:
- Using thread_info instead of per-CPU variable for the real TTBR0_EL1
value (mentioned above)
- Factored out the cpu_do_switch_mm errata workaround to a separate
macro and avoided the "errata" argument to the uaccess_enable asm
macro
- Fix build error with allnoconfig by moving the uaccess_* asm macros to
asm/uaccess.h and avoid some cyclic header includes
- _PSR_PAN_BIT moved to the non-uapi ptrace.h
- Use x21 instead of lr as temporary register in entry.S
As per v1, the code requires more testing, especially for combinations
where hardware PAN and/or UAO are present.
The patches are also available on this branch:
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux ttbr0-pan
Thanks for reviewing/testing.
Catalin Marinas (7):
arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro
arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1
arm64: Disable TTBR0_EL1 during normal kernel execution
arm64: Handle faults caused by inadvertent user access with PAN enabled
arm64: xen: Enable user access before a privcmd hvc call
arm64: Enable CONFIG_ARM64_TTBR0_PAN
arch/arm64/Kconfig | 8 ++
arch/arm64/include/asm/assembler.h | 37 +++++++++
arch/arm64/include/asm/cpufeature.h | 6 ++
arch/arm64/include/asm/efi.h | 14 ++++
arch/arm64/include/asm/futex.h | 14 ++--
arch/arm64/include/asm/kernel-pgtable.h | 7 ++
arch/arm64/include/asm/mmu_context.h | 32 ++++++--
arch/arm64/include/asm/ptrace.h | 2 +
arch/arm64/include/asm/thread_info.h | 3 +
arch/arm64/include/asm/uaccess.h | 136 ++++++++++++++++++++++++++++++--
arch/arm64/kernel/armv8_deprecated.c | 10 +--
arch/arm64/kernel/asm-offsets.c | 3 +
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/kernel/entry.S | 71 ++++++++++++++++-
arch/arm64/kernel/head.S | 6 +-
arch/arm64/kernel/setup.c | 8 ++
arch/arm64/kernel/vmlinux.lds.S | 5 ++
arch/arm64/lib/clear_user.S | 8 +-
arch/arm64/lib/copy_from_user.S | 8 +-
arch/arm64/lib/copy_in_user.S | 8 +-
arch/arm64/lib/copy_to_user.S | 8 +-
arch/arm64/mm/context.c | 7 +-
arch/arm64/mm/fault.c | 22 ++++--
arch/arm64/mm/proc.S | 12 +--
arch/arm64/xen/hypercall.S | 19 +++++
25 files changed, 381 insertions(+), 74 deletions(-)
next reply other threads:[~2016-09-02 15:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-02 15:02 Catalin Marinas [this message]
2016-09-02 15:02 ` [PATCH v2 1/7] arm64: Factor out PAN enabling/disabling into separate uaccess_* macros Catalin Marinas
2016-09-05 15:38 ` Mark Rutland
2016-09-12 14:52 ` Catalin Marinas
2016-09-12 15:09 ` Mark Rutland
2016-09-12 16:26 ` Catalin Marinas
2016-09-02 15:02 ` [PATCH v2 2/7] arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro Catalin Marinas
2016-09-05 16:11 ` Mark Rutland
2016-09-02 15:02 ` [PATCH v2 3/7] arm64: Introduce uaccess_{disable, enable} functionality based on TTBR0_EL1 Catalin Marinas
2016-09-05 17:20 ` Mark Rutland
2016-09-06 10:27 ` Catalin Marinas
2016-09-06 10:45 ` Mark Rutland
2016-09-11 13:55 ` [kernel-hardening] " Ard Biesheuvel
2016-09-12 9:32 ` Catalin Marinas
2016-09-09 17:15 ` Catalin Marinas
2016-09-02 15:02 ` [PATCH v2 4/7] arm64: Disable TTBR0_EL1 during normal kernel execution Catalin Marinas
2016-09-06 17:31 ` Mark Rutland
2016-09-02 15:02 ` [PATCH v2 5/7] arm64: Handle faults caused by inadvertent user access with PAN enabled Catalin Marinas
2016-09-02 15:02 ` [PATCH v2 6/7] arm64: xen: Enable user access before a privcmd hvc call Catalin Marinas
2016-09-02 15:02 ` [PATCH v2 7/7] arm64: Enable CONFIG_ARM64_TTBR0_PAN Catalin Marinas
2016-09-02 15:47 ` Mark Rutland
2016-09-07 23:20 ` [PATCH v2 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching Kees Cook
2016-09-08 12:51 ` Catalin Marinas
2016-09-08 15:50 ` Kees Cook
2016-09-09 16:31 ` Mark Rutland
2016-09-09 18:24 ` Kees Cook
2016-09-09 23:40 ` [kernel-hardening] " David Brown
2016-09-10 9:51 ` Catalin Marinas
2016-09-10 10:56 ` Ard Biesheuvel
2016-09-11 12:16 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1472828533-28197-1-git-send-email-catalin.marinas@arm.com \
--to=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).