linux/arch
Vladimir Murzin 72cd4064fc ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care of
ARMv8M introduces support for Security extension to M class, among
other things it affects exception handling, especially, encoding of
EXC_RETURN.

The new bits have been added:

Bit [6]	Secure or Non-secure stack
Bit [5]	Default callee register stacking
Bit [0]	Exception Secure

which conflicts with hard-coded value of EXC_RETURN:

In fact, we only care of few bits:

Bit [3]	 Mode (0 - Handler, 1 - Thread)
Bit [2]	 Stack pointer selection (0 - Main, 1 - Process)

We can toggle only those bits and left other bits as they were on
exception entry.

It is basically, what patch does - saves EXC_RETURN when we do
transition form Thread to Handler mode (it is first svc), so later
saved value is used instead of EXC_RET_THREADMODE_PROCESSSTACK.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-01 21:44:19 +00:00
..
alpha Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
arc arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
arm ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care of 2019-02-01 21:44:19 +00:00
arm64 Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
c6x arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
csky arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
h8300 arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
hexagon arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
ia64 arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
m68k arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
microblaze arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
mips arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
nds32 arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
nios2 arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
openrisc arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
parisc arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
powerpc arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
riscv arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
s390 Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
sh Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
sparc arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
um Merge branch 'akpm' (patches from Andrew) 2019-01-05 09:16:18 -08:00
unicore32 arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
x86 Kbuild late updates for v4.21 2019-01-06 16:33:10 -08:00
xtensa arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
.gitignore
Kconfig jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00