commit	7a3df10417b7cff573a2e9490652cc52164ce6cc	[log] [tgz]
author	Per Larsen <perl@immunant.com>	Wed Oct 21 00:35:21 2020 -0700
committer	Per Larsen <perl@immunant.com>	Tue Dec 01 13:52:56 2020 -0800
tree	e1819a35af5e49101df356cc675b498dbaf33204
parent	ede41f020d0a0ef78d0d32a934a31bdaab26f460 [diff]

[arch][arm64] Support user shadow call stack

Make the platform register (x18) point to the shadow call stack when
entering user space via the arch_enter_uspace function.

The DEFAULT_SHADOW_STACK_SIZE is PAGE_SIZE unless its size
is specified via the CUSTOM_DEFAULT_SHADOW_STACK_SIZE flag.
This mirrors the flags controlling the regular stack size.

Shadow call stack can be toggled via the USER_SCS_ENABLED flag. If
shadow call stack is disabled or unsupported, the stack protector
is enabled as a fallback mitigation.

Test: build.py qemu-generic-arm64-test-debug
Bug: 79994372
Change-Id: Idb345cd0eba3434cd9e9bf170de4be1297fa160c

9 files changed

tree: e1819a35af5e49101df356cc675b498dbaf33204

README.md

LK

The LK embedded kernel. An SMP-aware kernel designed for small systems.

See https://github.com/littlekernel/lk for the latest version.

See https://github.com/littlekernel/lk/wiki for documentation.

Builds

To build and test for ARM on linux

install or build qemu. v2.4 and above is recommended.
install gcc for embedded arm (see note 1)
run scripts/do-qemuarm (from the lk directory)
you should see ‘welcome to lk/MP’

This will get you a interactive prompt into LK which is running in qemu arm machine ‘virt’ emulation. type ‘help’ for commands.

note 1: for ubuntu: sudo apt-get install gcc-arm-none-eabi or fetch a prebuilt toolchain from http://newos.org/toolchains/arm-eabi-5.3.0-Linux-x86_64.tar.xz