Will Deacon a14949e09a arm64: cmpxchg: truncate sub-word signed types before comparison ...

When performing a cmpxchg operation on a signed sub-word type (e.g. s8),
we need to ensure that the upper register bits of the "old" value used
for comparison are zeroed, otherwise we may erroneously fail the cmpxchg
which may even be interpreted as success by the caller (if the compiler
performs the truncation as part of its check). This has been observed
in mod_state, where negative values where causing problems with
this_cpu_cmpxchg.

This patch fixes the issue by explicitly casting 8-bit and 16-bit "old"
values using unsigned types in our cmpxchg wrappers. 32-bit types can be
left alone, since the underlying asm makes use of W registers in this
case.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

2015-07-30 20:16:53 +01:00

..

alpha

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

arc

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

arm

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

arm64

arm64: cmpxchg: truncate sub-word signed types before comparison

2015-07-30 20:16:53 +01:00

avr32

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

blackfin

atomic: Replace atomic_{set,clear}_mask() usage

2015-07-27 14:06:24 +02:00

c6x

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

cris

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

frv

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

h8300

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

hexagon

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

ia64

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

m32r

atomic: Replace atomic_{set,clear}_mask() usage

2015-07-27 14:06:24 +02:00

m68k

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

metag

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

microblaze

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

mips

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

mn10300

atomic: Replace atomic_{set,clear}_mask() usage

2015-07-27 14:06:24 +02:00

nios2

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

openrisc

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

parisc

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

powerpc

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

s390

atomic: Replace atomic_{set,clear}_mask() usage

2015-07-27 14:06:24 +02:00

score

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

sh

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

sparc

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

tile

atomic: Provide atomic_{or,xor,and}

2015-07-27 14:06:24 +02:00

um

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

unicore32

mm: clean up per architecture MM hook header files

2015-07-17 16:39:53 -07:00

x86

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

xtensa

atomic: Collapse all atomic_{set,clear}_mask definitions

2015-07-27 14:06:24 +02:00

.gitignore

…

Kconfig

x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86

2015-07-18 03:42:51 +02:00