s390/asm-offsets: Remove ASM_OFFSETS_C

Remove ASM_OFFSETS_C which is used as guard in thread_info.h to decide if
asm-offsets can be included or not.

There is no reason to include asm-offsets.h in t

s390/asm-offsets: Remove ASM_OFFSETS_C

Remove ASM_OFFSETS_C which is used as guard in thread_info.h to decide if
asm-offsets can be included or not.

There is no reason to include asm-offsets.h in thread_info.h anymore.
Remove the define and the not needed include. Explicitly include
asm-offsets.h in all header files which require it, and where it used
to be included implicitly via thread_info.h.

This reduces header dependencies.

Acked-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390: Rely on generic printing of preemption model

die() invokes later show_regs() -> show_regs_print_info() which prints
the current preemption model.
Remove it from the initial line.

Signed-off-b

s390: Rely on generic printing of preemption model

die() invokes later show_regs() -> show_regs_print_info() which prints
the current preemption model.
Remove it from the initial line.

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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s390: Replace S390_lowcore by get_lowcore()

Replace all S390_lowcore usages in arch/s390/ by get_lowcore().

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Sven Schnelle <[email protected]

s390: Replace S390_lowcore by get_lowcore()

Replace all S390_lowcore usages in arch/s390/ by get_lowcore().

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Sven Schnelle <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390/dumpstack: simplify in stack logic code

The pattern for all in_<type>_stack() functions is the same; especially
also the size of all stacks is the same. Simplify the code by passing only
the st

s390/dumpstack: simplify in stack logic code

The pattern for all in_<type>_stack() functions is the same; especially
also the size of all stacks is the same. Simplify the code by passing only
the stack address to the generic in_stack() helper, which then can assume a
THREAD_SIZE sized stack.

Reviewed-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390/dumpstack: resolve userspace last_break

report_user_fault() currently does not show which library last_break
points to. Call print_vma_addr() to find out; the output now looks
like this:

L

s390/dumpstack: resolve userspace last_break

report_user_fault() currently does not show which library last_break
points to. Call print_vma_addr() to find out; the output now looks
like this:

Last Breaking-Event-Address:
[<000003ffaa2a56e4>] libc.so.6[3ffaa180000+251000]

For kernel it's unchanged:

Last Breaking-Event-Address:
[<000000000030fd06>] trace_hardirqs_on+0x56/0xc8

Signed-off-by: Ilya Leoshkevich <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

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exit: Add and use make_task_dead.

There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something c

exit: Add and use make_task_dead.

There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <[email protected]>

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s390/ptrace: add last_break member to pt_regs

Instead of using args[0] for the value of the last breaking event
address register, add a member to make things more obvious.

Signed-off-by: Sven Schne

s390/ptrace: add last_break member to pt_regs

Instead of using args[0] for the value of the last breaking event
address register, add a member to make things more obvious.

Signed-off-by: Sven Schnelle <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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exit: Remove calls of do_exit after noreturn versions of die

On nds32, openrisc, s390, sh, and xtensa the function die never
returns. Mark die __noreturn so that no one expects die to return.
Remov

exit: Remove calls of do_exit after noreturn versions of die

On nds32, openrisc, s390, sh, and xtensa the function die never
returns. Mark die __noreturn so that no one expects die to return.
Remove the do_exit calls after die as they will never be reached.

Cc: Jonas Bonn <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: [email protected]
Cc: Nick Hu <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: [email protected]
Cc: Yoshinori Sato <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Chris Zankel <[email protected]>
Cc: Max Filippov <[email protected]>
Fixes: 2.3.16
Fixes: 2.3.99-pre8
Fixes: 3f65ce4d141e ("[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 5")
Fixes: 664eec400bf8 ("nds32: MMU fault handling and page table management")
Fixes: 61e85e367535 ("OpenRISC: Memory management")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Eric W. Biederman <[email protected]>

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s390/unwind: add machine check handler stack

Fixes: b61b1595124a ("s390: add stack for machine check handler")
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <hca@lin

s390/unwind: add machine check handler stack

Fixes: b61b1595124a ("s390: add stack for machine check handler")
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

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kernel: rename show_stack_loglvl() => show_stack()

Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
a

kernel: rename show_stack_loglvl() => show_stack()

Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().

Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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s390: add show_stack_loglvl()

Currently, the log-level of show_stack() depends on a platform
realization. It creates situations where the headers are printed with
lower log level or higher than the

s390: add show_stack_loglvl()

Currently, the log-level of show_stack() depends on a platform
realization. It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side. In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages. And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers. Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/[email protected]/T/#u

Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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sched/rt, s390: Use CONFIG_PREEMPTION

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONF

sched/rt, s390: Use CONFIG_PREEMPTION

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the preemption and entry code over to use CONFIG_PREEMPTION. Add
PREEMPT_RT output to die().

[bigeasy: +Kconfig, dumpstack.c]

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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s390/unwind: add stack pointer alignment sanity checks

ABI requires SP to be aligned 8 bytes, report unwinding error otherwise.

Link: https://lkml.kernel.org/r/[email protected]

s390/unwind: add stack pointer alignment sanity checks

ABI requires SP to be aligned 8 bytes, report unwinding error otherwise.

Link: https://lkml.kernel.org/r/[email protected]
Reviewed-by: Heiko Carstens <[email protected]>
Tested-by: Miroslav Benes <[email protected]>
Signed-off-by: Miroslav Benes <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390/test_unwind: print verbose unwinding results

Add stack name, sp and reliable information into test unwinding
results. Also consider ip outside of kernel text as failure if the
state is reported

s390/test_unwind: print verbose unwinding results

Add stack name, sp and reliable information into test unwinding
results. Also consider ip outside of kernel text as failure if the
state is reported reliable.

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390/unwind: unify task is current checks

Avoid mixture of task == NULL and task == current meaning the same
thing and simply always initialize task with current in unwind_start.

Reviewed-by: Heiko

s390/unwind: unify task is current checks

Avoid mixture of task == NULL and task == current meaning the same
thing and simply always initialize task with current in unwind_start.

Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390/unwind: remove stack recursion warning

Remove pointless stack recursion on stack type ... warning, which
only confuses people. There is no way to make backchain unwinder 100%
reliable. When a t

s390/unwind: remove stack recursion warning

Remove pointless stack recursion on stack type ... warning, which
only confuses people. There is no way to make backchain unwinder 100%
reliable. When a task is interrupted in-between stack frame allocation
and backchain write instructions new stack frame backchain pointer is
left uninitialized (there are also sometimes additional instruction
in-between stack frame allocation and backchain write instructions due
to gcc shrink-wrapping). In attempt to unwind such stack the unwinder
would still try to use that invalid backchain value and perform all kind
of sanity checks on it to make sure we are not pointed out of stack. In
some cases that invalid backchain value would be 0 and we would falsely
treat next stackframe as pt_regs and again gprs[15] in those pt_regs
might happen to point at some address within the task's stack.

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

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s390: enforce CONFIG_SMP

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

s390: enforce CONFIG_SMP

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 <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

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s390/unwind: introduce stack unwind API

Rework the dump_trace() stack unwinder interface to support different
unwinding algorithms. The new interface looks like this:

struct unwind_state state;
u

s390/unwind: introduce stack unwind API

Rework the dump_trace() stack unwinder interface to support different
unwinding algorithms. The new interface looks like this:

struct unwind_state state;
unwind_for_each_frame(&state, task, regs, start_stack)
do_something(state.sp, state.ip, state.reliable);

The unwind_bc.c file contains the implementation for the classic
back-chain unwinder.

One positive side effect of the new code is it now handles ftraced
functions gracefully. It prints the real name of the return function
instead of 'return_to_handler'.

Signed-off-by: Martin Schwidefsky <[email protected]>

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s390/dumpstack: print psw mask and address again

With pointer obfuscation the output of show_registers() became quite useless:

Krnl PSW : (____ptrval____) (____ptrval____) (__list_add_valid+0x98/0x

s390/dumpstack: print psw mask and address again

With pointer obfuscation the output of show_registers() became quite useless:

Krnl PSW : (____ptrval____) (____ptrval____) (__list_add_valid+0x98/0xa8)

In order to print the psw mask and address use %px instead of %p.
And the output looks again like this:

Krnl PSW : 0404d00180000000 00000000007c0dd0 (__list_add_valid+0x98/0xa8)

Reviewed-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390/dumpstack: disable __dump_trace kasan instrumentation

Walking async_stack produces false positives. Disable __dump_trace
function instrumentation for now.

Signed-off-by: Vasily Gorbik <gor@lin

s390/dumpstack: disable __dump_trace kasan instrumentation

Walking async_stack produces false positives. Disable __dump_trace
function instrumentation for now.

Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390: unify stack size definitions

Remove STACK_ORDER and STACK_SIZE in favour of identical THREAD_SIZE_ORDER
and THREAD_SIZE definitions. THREAD_SIZE and THREAD_SIZE_ORDER naming is
misleading sinc

s390: unify stack size definitions

Remove STACK_ORDER and STACK_SIZE in favour of identical THREAD_SIZE_ORDER
and THREAD_SIZE definitions. THREAD_SIZE and THREAD_SIZE_ORDER naming is
misleading since it is used as general kernel stack size information. But
both those definitions are used in the common code and throughout
architectures specific code, so changing the naming is problematic.

Reviewed-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390: add support for virtually mapped kernel stacks

With virtually mapped kernel stacks the kernel stack overflow detection
is now fault based, every stack has a guard page in the vmalloc space.
Th

s390: add support for virtually mapped kernel stacks

With virtually mapped kernel stacks the kernel stack overflow detection
is now fault based, every stack has a guard page in the vmalloc space.
The panic_stack is renamed to nodat_stack and is used for all function
that need to run without DAT, e.g. memcpy_real or do_start_kdump.

The main effect is a reduction in the kernel image size as with vmap
stacks the old style overflow checking that adds two instructions per
function is not needed anymore. Result from bloat-o-meter:

add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042)

In regard to performance the micro-benchmark for fork has a hit of a
few microseconds, allocating 4 pages in vmalloc space is more expensive
compare to an order-2 page allocation. But with real workload I could
not find a noticeable difference.

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390: kernel: add SPDX identifiers to the remaining files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/kerne

s390: kernel: add SPDX identifiers to the remaining files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/kernel/ files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390/mm: use new mm defines instead of magic values

Reviewed-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefs

s390/mm: use new mm defines instead of magic values

Reviewed-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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s390: rename struct psw_bits members

Rename a couple of the struct psw_bits members so it is more obvious
for what they are good. Initially I thought using the single character
names from the PoP wo

s390: rename struct psw_bits members

Rename a couple of the struct psw_bits members so it is more obvious
for what they are good. Initially I thought using the single character
names from the PoP would be sufficient and obvious, but admittedly
that is not true.

The current implementation is not easy to use, if one has to look into
the source file to figure out which member represents the 'per' bit
(which is the 'r' member).

Therefore rename the members to sane names that are identical to the
uapi psw mask defines:

r -> per
i -> io
e -> ext
t -> dat
m -> mcheck
w -> wait
p -> pstate

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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