From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Fri, 17 Jul 2015 18:30:15 +0100 Subject: [PATCH v2 0/6] arm64: kernel: Add support for Privileged Access Never Message-ID: <1437154221-5736-1-git-send-email-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This series adds support for Privileged Access Never (PAN; part of the ARMv8.1 Extensions). When enabled, this feature causes a permission fault if the kernel attempts to access memory that is also accessible by userspace - instead the PAN bit must be cleared when accessing userspace memory. (or use the ldt*/stt* instructions). This series detects and enables this feature, and uses alternatives to change {get,put}_user() et al to clear the PAN bit while they do their work. Changes since v1: * Copied cpuid_feature_extract_field() from arch/arm as a new patch, suggested by Russell King [1]. * Changed feature-detection patch to use cpuid_feature_extract_field() for sign extension, and '>='. * Moved SCTLR_EL1_* from asm/cputype.h to asm/sysreg.h * Added PSR_PAN_BIT in uapi/asm/ptrace.h * Removed the setting of PSTATE_PAN in kernel/process.c [1] http://www.spinics.net/lists/arm-kernel/msg432518.html James Morse (6): arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension arm64: kernel: preparatory: Move config_sctlr_el1 arm64: kernel: Add cpufeature 'enable' callback arm64: kernel: Add min_register_value and use '>=' for feature detection arm64: kernel: Add optional CONFIG_ parameter to ALTERNATIVE() arm64: kernel: Add support for Privileged Access Never arch/arm64/Kconfig | 14 +++++++++++++ arch/arm64/include/asm/alternative.h | 28 ++++++++++++++++++++++--- arch/arm64/include/asm/cpufeature.h | 21 ++++++++++++++++--- arch/arm64/include/asm/cputype.h | 3 --- arch/arm64/include/asm/futex.h | 8 ++++++++ arch/arm64/include/asm/processor.h | 2 ++ arch/arm64/include/asm/sysreg.h | 21 +++++++++++++++++++ arch/arm64/include/asm/uaccess.h | 11 ++++++++++ arch/arm64/include/uapi/asm/ptrace.h | 1 + arch/arm64/kernel/armv8_deprecated.c | 11 +--------- arch/arm64/kernel/cpufeature.c | 40 +++++++++++++++++++++++++++++++++--- 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/fault.c | 23 +++++++++++++++++++++ 16 files changed, 193 insertions(+), 22 deletions(-) -- 2.1.4