linux.git/arch/s390/lib, branch v5.3.2

s390/lib: add missing include

2019-07-29T16:05:02+00:00

Include  into arch/s390/lib/xor.c to expose xor_block_xc
declaration and avoid the following sparse warning:
arch/s390/lib/xor.c:128:27: warning: symbol 'xor_block_xc' was not declared. Should it be static?

Signed-off-by: Vasily Gorbik

s390: enforce CONFIG_SMP

2019-06-07T08:09:37+00:00

There never have been distributions that shiped with CONFIG_SMP=n for
s390. In addition the kernel currently doesn't even compile with
CONFIG_SMP=n for s390. Most likely it wouldn't even work, even if we
fix the compile error, since nobody tests it, since there is no use
case that I can think of.
Therefore simply enforce CONFIG_SMP and get rid of some more or
less unused code.

Reviewed-by: Christian Borntraeger 
Signed-off-by: Heiko Carstens

s390: add missing ENDPROC statements to assembler functions

2019-05-02T11:54:11+00:00

The assembler code in arch/s390 misses proper ENDPROC statements
to properly end functions in a few places. Add them.

Signed-off-by: Martin Schwidefsky

s390/kasan: improve string/memory functions checks

2019-01-18T08:34:18+00:00

Avoid using arch specific implementations of string/memory functions
with KASAN since gcc cannot instrument asm code memory accesses and
many bugs could be missed.

Acked-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Martin Schwidefsky

s390/kasan: avoid user access code instrumentation

2018-10-09T09:21:21+00:00

Kasan instrumentation adds "store" check for variables marked as
modified by inline assembly. With user pointers containing addresses
from another address space this produces false positives.

static inline unsigned long clear_user_xc(void __user *to, ...)
{
	asm volatile(
	...
	: "+a" (to) ...

User space access functions are wrapped by manually instrumented
functions in kasan common code, which should be sufficient to catch
errors. So, we just disable uaccess.o instrumentation altogether.

Reviewed-by: Martin Schwidefsky 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Martin Schwidefsky

s390/kasan: replace some memory functions

2018-10-09T09:21:18+00:00

Follow the common kasan approach:

    "KASan replaces memory functions with manually instrumented
    variants.  Original functions declared as weak symbols so strong
    definitions in mm/kasan/kasan.c could replace them. Original
    functions have aliases with '__' prefix in name, so we could call
    non-instrumented variant if needed."

Signed-off-by: Vasily Gorbik 
Signed-off-by: Martin Schwidefsky

s390/lib: use expoline for all bcr instructions

2018-08-07T11:38:13+00:00

The memove, memset, memcpy, __memset16, __memset32 and __memset64
function have an additional indirect return branch in form of a
"bzr" instruction. These need to use expolines as well.

Cc:  # v4.17+
Fixes: 97489e0663 ("s390/lib: use expoline for indirect branches")
Reviewed-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: introduce compile time check for empty .bss section

2018-05-09T08:55:01+00:00

Introduce compile time check for files which should avoid using .bss
section, because of the following reasons:
- .bss section has not been zeroed yet,
- initrd has not been moved to a safe location and could be overlapping
with .bss section.

Reviewed-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Martin Schwidefsky

s390/lib: use expoline for indirect branches

2018-05-07T07:07:36+00:00

The return from the memmove, memset, memcpy, __memset16, __memset32 and
__memset64 functions are done with "br %r14". These are indirect branches
as well and need to use execute trampolines for CONFIG_EXPOLINE=y.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

s390: fix preemption race in disable_sacf_uaccess

2017-12-15T14:05:21+00:00

With CONFIG_PREEMPT=y there is a possible race in disable_sacf_uaccess.

The new set_fs value needs to be stored the the task structure first,
the control register update needs to be second. Otherwise a preemptive
schedule may interrupt the code right after the control register update
has been done and the next time the task is scheduled we get an incorrect
value in the control register due to the old set_fs setting.

Fixes: 0aaba41b58 ("s390: remove all code using the access register mode")
Signed-off-by: Martin Schwidefsky