linux/arch/s390
Heiko Carstens 00de54c803 s390/mem_detect: fix memory type of first block
Fix a long-standing but currently irrelevant bug: the memory detection
code performs a tprot instruction on address zero to figure out if the
first memory chunk is readable or writable. Due to low address
protection the result is "read-only". If the memory detection code
would actually care, it would have to ignore the first memory
increment, but it adds the memory increment to writable memory anyway.

If memblock debugging is enabled this leads to an extra rather
surprising call which registers memory. To avoid this get rid of the
first misleading tprot call and simply assume that the first memory
increment is writable. Otherwise we wouldn't have reached the memory
detection code anyway.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-16 07:27:54 +01:00
..
appldata Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
boot Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
configs s390: update defconfigs 2017-01-16 07:27:48 +01:00
crypto Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hypfs s390: hypfs: make inode explicitly non-modular 2016-10-31 17:55:40 +01:00
include s390/pci: use proper endianness annotations 2017-01-16 07:27:53 +01:00
kernel s390/setup: call memblock_reserve only for size > 0 2017-01-16 07:27:53 +01:00
kvm ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
lib s390/lib: improve memmove, memset and memcpy 2017-01-16 07:27:51 +01:00
mm s390/mem_detect: fix memory type of first block 2017-01-16 07:27:54 +01:00
net bpf: xdp: Allow head adjustment in XDP prog 2016-12-08 14:25:13 -05:00
numa s390/numa: pin all possible cpus to nodes early 2016-12-07 07:23:33 +01:00
oprofile s390/dumpstack: restore reliable indicator for call traces 2016-10-17 14:44:30 +02:00
pci s390/pci: use proper endianness annotations 2017-01-16 07:27:53 +01:00
tools s390: remove unneeded dependency for gen_facilities 2016-11-08 10:30:28 +01:00
defconfig s390: update defconfigs 2017-01-16 07:27:48 +01:00
Kbuild s390/numa: add core infrastructure 2015-08-03 18:40:25 +02:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2016-12-13 16:33:33 -08:00
Kconfig.debug arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug 2016-01-09 06:30:49 -08:00
Makefile s390: add assembler include path for vx-insn.h 2016-09-06 11:00:04 +02:00