From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 7/7] arm64: Enable CONFIG_ARM64_TTBR0_PAN
Date: Fri, 2 Sep 2016 16:02:13 +0100 [thread overview]
Message-ID: <1472828533-28197-8-git-send-email-catalin.marinas@arm.com> (raw)
In-Reply-To: <1472828533-28197-1-git-send-email-catalin.marinas@arm.com>
This patch adds the Kconfig option to enable support for TTBR0 PAN. The
option is default off because of a slight performance hit when enabled,
caused by the additional TTBR0_EL1 switching during user access
operations or exception entry/exit code.
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/Kconfig | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index bc3f00f586f1..3fb9a6ce464d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -785,6 +785,14 @@ config SETEND_EMULATION
If unsure, say Y
endif
+config ARM64_TTBR0_PAN
+ bool "Priviledged Access Never using TTBR0_EL1 switching"
+ help
+ Enabling this option prevents the kernel from accessing
+ user-space memory directly by pointing TTBR0_EL1 to a reserved
+ zeroed area and reserved ASID. The user access routines
+ restore the valid TTBR0_EL1 temporarily.
+
menu "ARMv8.1 architectural features"
config ARM64_HW_AFDBM
next prev parent 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 [PATCH v2 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching Catalin Marinas
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 ` Catalin Marinas [this message]
2016-09-02 15:47 ` [PATCH v2 7/7] arm64: Enable CONFIG_ARM64_TTBR0_PAN 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=1472828533-28197-8-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).