linux.git/arch/s390, branch v5.4.64

s390: don't trace preemption in percpu macros

2020-09-09T17:12:22+00:00

[ Upstream commit 1196f12a2c960951d02262af25af0bb1775ebcc2 ]

Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context}
to per-cpu variables") the lockdep code itself uses percpu variables. This
leads to recursions because the percpu macros are calling preempt_enable()
which might call trace_preempt_on().

Signed-off-by: Sven Schnelle 
Reviewed-by: Vasily Gorbik 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Sasha Levin

s390/numa: set node distance to LOCAL_DISTANCE

2020-09-03T09:26:50+00:00

[ Upstream commit 535e4fc623fab2e09a0653fc3a3e17f382ad0251 ]

The node distance is hardcoded to 0, which causes a trouble
for some user-level applications. In particular, "libnuma"
expects the distance of a node to itself as LOCAL_DISTANCE.
This update removes the offending node distance override.

Cc:  # 4.4
Fixes: 3a368f742da1 ("s390/numa: add core infrastructure")
Signed-off-by: Alexander Gordeev 
Signed-off-by: Heiko Carstens 
Signed-off-by: Sasha Levin

s390/ptrace: fix storage key handling

2020-08-26T08:41:02+00:00

[ Upstream commit fd78c59446b8d050ecf3e0897c5a486c7de7c595 ]

The key member of the runtime instrumentation control block contains
only the access key, not the complete storage key. Therefore the value
must be shifted by four bits. Since existing user space does not
necessarily query and set the access key correctly, just ignore the
user space provided key and use the correct one.
Note: this is only relevant for debugging purposes in case somebody
compiles a kernel with a default storage access key set to a value not
equal to zero.

Fixes: 262832bc5acd ("s390/ptrace: add runtime instrumention register get/set")
Reported-by: Claudio Imbrenda 
Signed-off-by: Heiko Carstens 
Signed-off-by: Sasha Levin

s390/runtime_instrumentation: fix storage key handling

2020-08-26T08:41:02+00:00

[ Upstream commit 9eaba29c7985236e16468f4e6a49cc18cf01443e ]

The key member of the runtime instrumentation control block contains
only the access key, not the complete storage key. Therefore the value
must be shifted by four bits.
Note: this is only relevant for debugging purposes in case somebody
compiles a kernel with a default storage access key set to a value not
equal to zero.

Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation")
Reported-by: Claudio Imbrenda 
Signed-off-by: Heiko Carstens 
Signed-off-by: Sasha Levin

s390/gmap: improve THP splitting

2020-08-19T06:16:29+00:00

commit ba925fa35057a062ac98c3e8138b013ce4ce351c upstream.

During s390_enable_sie(), we need to take care of splitting all qemu user
process THP mappings. This is currently done with follow_page(FOLL_SPLIT),
by simply iterating over all vma ranges, with PAGE_SIZE increment.

This logic is sub-optimal and can result in a lot of unnecessary overhead,
especially when using qemu and ASAN with large shadow map. Ilya reported
significant system slow-down with one CPU busy for a long time and overall
unresponsiveness.

Fix this by using walk_page_vma() and directly calling split_huge_pmd()
only for present pmds, which greatly reduces overhead.

Cc:  # v5.4+
Reported-by: Ilya Leoshkevich 
Tested-by: Ilya Leoshkevich 
Acked-by: Christian Borntraeger 
Signed-off-by: Gerald Schaefer 
Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

s390/maccess: add no DAT mode to kernel_write

2020-07-16T06:16:48+00:00

[ Upstream commit d6df52e9996dcc2062c3d9c9123288468bb95b52 ]

To be able to patch kernel code before paging is initialized do plain
memcpy if DAT is off. This is required to enable early jump label
initialization.

Reviewed-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Heiko Carstens 
Signed-off-by: Sasha Levin

s390: Change s390_kernel_write() return type to match memcpy()

2020-07-16T06:16:48+00:00

[ Upstream commit cb2cceaefb4c4dc28fc27ff1f1b2d258bfc10353 ]

s390_kernel_write()'s function type is almost identical to memcpy().
Change its return type to "void *" so they can be used interchangeably.

Cc: linux-s390@vger.kernel.org
Cc: heiko.carstens@de.ibm.com
Signed-off-by: Josh Poimboeuf 
Acked-by: Joe Lawrence 
Acked-by: Miroslav Benes 
Acked-by: Gerald Schaefer  # s390
Signed-off-by: Jiri Kosina 
Signed-off-by: Sasha Levin

s390/mm: fix huge pte soft dirty copying

2020-07-16T06:16:47+00:00

commit 528a9539348a0234375dfaa1ca5dbbb2f8f8e8d2 upstream.

If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty).
This fixes some cases for guest migration with huge page backings.

Cc:  # 4.8
Fixes: bc29b7ac1d9f ("s390/mm: clean up pte/pmd encoding")
Reviewed-by: Christian Borntraeger 
Reviewed-by: Gerald Schaefer 
Signed-off-by: Janosch Frank 
Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

s390/setup: init jump labels before command line parsing

2020-07-16T06:16:46+00:00

commit 95e61b1b5d6394b53d147c0fcbe2ae70fbe09446 upstream.

Command line parameters might set static keys. This is true for s390 at
least since commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1
and init_on_free=1 boot options"). To avoid the following WARN:

static_key_enable_cpuslocked(): static key 'init_on_alloc+0x0/0x40' used
before call to jump_label_init()

call jump_label_init() just before parse_early_param().
jump_label_init() is safe to call multiple times (x86 does that), doesn't
do any memory allocations and hence should be safe to call that early.

Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Cc:  # 5.3: d6df52e9996d: s390/maccess: add no DAT mode to kernel_write
Cc:  # 5.3
Reviewed-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

s390/kasan: fix early pgm check handler execution

2020-07-16T06:16:35+00:00

[ Upstream commit 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 ]

Currently if early_pgm_check_handler is called it ends up in pgm check
loop. The problem is that early_pgm_check_handler is instrumented by
KASAN but executed without DAT flag enabled which leads to addressing
exception when KASAN checks try to access shadow memory.

Fix that by executing early handlers with DAT flag on under KASAN as
expected.

Reported-and-tested-by: Alexander Egorenkov 
Reviewed-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Heiko Carstens 
Signed-off-by: Sasha Levin