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2021-02-09s390/entry: use cpu alternative for stck/stckfHeiko Carstens
Use a cpu alternative to switch between stck and stckf instead of making it compile time dependent. This will also make kernels compiled for old machines, but running on newer machines, use stckf. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-01-19s390: convert to generic entrySven Schnelle
This patch converts s390 to use the generic entry infrastructure from kernel/entry/*. There are a few special things on s390: - PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't know about our PIF flags in exit_to_user_mode_loop(). - The old code had several ways to restart syscalls: a) PIF_SYSCALL_RESTART, which was only set during execve to force a restart after upgrading a process (usually qemu-kvm) to pgste page table extensions. b) PIF_SYSCALL, which is set by do_signal() to indicate that the current syscall should be restarted. This is changed so that do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use PIF_SYSCALL doesn't work with the generic code, and changing it to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART more unique. - On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by executing a svc instruction on the process stack which causes a fault. While handling that fault the fault code sets PIF_SYSCALL to hand over processing to the syscall code on exit to usermode. The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets a return value for a syscall. The s390x ptrace ABI uses r2 both for the syscall number and return value, so ptrace cannot set the syscall number + return value at the same time. The flag makes handling that a bit easier. do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET is set. CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY. CR1/7/13 will be checked both on kernel entry and exit to contain the correct asces. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-12-18Merge tag 's390-5.11-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: "This is mainly to decouple udelay() and arch_cpu_idle() and simplify both of them. Summary: - Always initialize kernel stack backchain when entering the kernel, so that unwinding works properly. - Fix stack unwinder test case to avoid rare interrupt stack corruption. - Simplify udelay() and just let it busy loop instead of implementing a complex logic. - arch_cpu_idle() cleanup. - Some other minor improvements" * tag 's390-5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: convert comma to semicolon s390/idle: allow arch_cpu_idle() to be kprobed s390/idle: remove raw_local_irq_save()/restore() from arch_cpu_idle() s390/idle: merge enabled_wait() and arch_cpu_idle() s390/delay: remove udelay_simple() s390/irq: select HAVE_IRQ_EXIT_ON_IRQ_STACK s390/delay: simplify udelay s390/test_unwind: use timer instead of udelay s390/test_unwind: fix CALL_ON_STACK tests s390: make calls to TRACE_IRQS_OFF/TRACE_IRQS_ON balanced s390: always clear kernel stack backchain before calling functions
2020-12-16Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe: "This sits on top of of the core entry/exit and x86 entry branch from the tip tree, which contains the generic and x86 parts of this work. Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL. With that done, we can get rid of JOBCTL_TASK_WORK from task_work and signal.c, and also remove a deadlock work-around in io_uring around knowing that signal based task_work waking is invoked with the sighand wait queue head lock. The motivation for this work is to decouple signal notify based task_work, of which io_uring is a heavy user of, from sighand. The sighand lock becomes a huge contention point, particularly for threaded workloads where it's shared between threads. Even outside of threaded applications it's slower than it needs to be. Roman Gershman <romger@amazon.com> reported that his networked workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all spent hammering on the sighand lock, showing 57% of the CPU time there [1]. There are further cleanups possible on top of this. One example is TIF_PATCH_PENDING, where a patch already exists to use TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more consolidation, but the work stands on its own as well" [1] https://github.com/axboe/liburing/issues/215 * tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits) io_uring: remove 'twa_signal_ok' deadlock work-around kernel: remove checking for TIF_NOTIFY_SIGNAL signal: kill JOBCTL_TASK_WORK io_uring: JOBCTL_TASK_WORK is no longer used by task_work task_work: remove legacy TWA_SIGNAL path sparc: add support for TIF_NOTIFY_SIGNAL riscv: add support for TIF_NOTIFY_SIGNAL nds32: add support for TIF_NOTIFY_SIGNAL ia64: add support for TIF_NOTIFY_SIGNAL h8300: add support for TIF_NOTIFY_SIGNAL c6x: add support for TIF_NOTIFY_SIGNAL alpha: add support for TIF_NOTIFY_SIGNAL xtensa: add support for TIF_NOTIFY_SIGNAL arm: add support for TIF_NOTIFY_SIGNAL microblaze: add support for TIF_NOTIFY_SIGNAL hexagon: add support for TIF_NOTIFY_SIGNAL csky: add support for TIF_NOTIFY_SIGNAL openrisc: add support for TIF_NOTIFY_SIGNAL sh: add support for TIF_NOTIFY_SIGNAL um: add support for TIF_NOTIFY_SIGNAL ...
2020-12-16s390/delay: simplify udelayHeiko Carstens
udelay is implemented by using quite subtle details to make it possible to load an idle psw and waiting for an interrupt even in irq context or when interrupts are disabled. Also handling (or better: no handling) of softirqs is taken into account. All this is done to optimize for something which should in normal circumstances never happen: calling udelay to busy wait. Therefore get rid of the whole complexity and just busy loop like other architectures are doing it also. It could have been possible to use diag 0x44 instead of cpu_relax() in the busy loop, however we have seen too many bad things happen with diag 0x44 that it seems to be better to simply busy loop. Also note that with this new implementation kernel preemption does work when within the udelay loop. This did not work before. To get a feeling what the former code optimizes for: IPL'ing a kernel with 'defconfig' and afterwards compiling a kernel ends with a total of zero udelay calls. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-16s390: make calls to TRACE_IRQS_OFF/TRACE_IRQS_ON balancedHeiko Carstens
In case of udelay CIF_IGNORE_IRQ is set. This leads to an unbalanced call of TRACE_IRQS_OFF and TRACE_IRQS_ON. That is: from lockdep's point of view TRACE_IRQS_ON is called one time too often. This doesn't fix any real bug, just makes the calls balanced. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-16s390: always clear kernel stack backchain before calling functionsHeiko Carstens
Clear the kernel stack backchain before potentially calling the lockdep trace_hardirqs_off/on functions. Without this walking the kernel backchain, e.g. during a panic, might stop too early. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-14Merge tag 's390-5.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add support for the hugetlb_cma command line option to allocate gigantic hugepages using CMA - Add arch_get_random_long() support. - Add ap bus userspace notifications. - Increase default size of vmalloc area to 512GB and otherwise let it increase dynamically by the size of physical memory. This should fix all occurrences where the vmalloc area was not large enough. - Completely get rid of set_fs() (aka select SET_FS) and rework address space handling while doing that; making address space handling much more simple. - Reimplement getcpu vdso syscall in C. - Add support for extended SCLP responses (> 4k). This allows e.g. to handle also potential large system configurations. - Simplify KASAN by removing 3-level page table support and only supporting 4-levels from now on. - Improve debug-ability of the kernel decompressor code, which now prints also stack traces and symbols in case of problems to the console. - Remove more power management leftovers. - Other various fixes and improvements all over the place. * tag 's390-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (62 commits) s390/mm: add support to allocate gigantic hugepages using CMA s390/crypto: add arch_get_random_long() support s390/smp: perform initial CPU reset also for SMT siblings s390/mm: use invalid asce for user space when switching to init_mm s390/idle: fix accounting with machine checks s390/idle: add missing mt_cycles calculation s390/boot: add build-id to decompressor s390/kexec_file: fix diag308 subcode when loading crash kernel s390/cio: fix use-after-free in ccw_device_destroy_console s390/cio: remove pm support from ccw bus driver s390/cio: remove pm support from css-bus driver s390/cio: remove pm support from IO subchannel drivers s390/cio: remove pm support from chsc subchannel driver s390/vmur: remove unused pm related functions s390/tape: remove unsupported PM functions s390/cio: remove pm support from eadm-sch drivers s390: remove pm support from console drivers s390/dasd: remove unused pm related functions s390/zfcp: remove pm support from zfcp driver s390/ap: let bus_register() add the AP bus sysfs attributes ...
2020-12-09s390/idle: fix accounting with machine checksSven Schnelle
When a machine check interrupt is triggered during idle, the code is using the async timer/clock for idle time calculation. It should use the machine check enter timer/clock which is passed to the macro. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09s390/idle: add missing mt_cycles calculationSven Schnelle
During removal of the critical section cleanup the calculation of mt_cycles during idle was removed. This causes invalid accounting on systems with SMT enabled. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02s390: fix irq state tracingHeiko Carstens
With commit 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") common code calls arch_cpu_idle() with a lockdep state that tells irqs are on. This doesn't work very well for s390: psw_idle() will enable interrupts to wait for an interrupt. As soon as an interrupt occurs the interrupt handler will verify if the old context was psw_idle(). If that is the case the interrupt enablement bits in the old program status word will be cleared. A subsequent test in both the external as well as the io interrupt handler checks if in the old context interrupts were enabled. Due to the above patching of the old program status word it is assumed the old context had interrupts disabled, and therefore a call to TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in turn makes lockdep incorrectly "think" that interrupts are enabled within the interrupt handler. Fix this by unconditionally calling TRACE_IRQS_OFF when entering interrupt handlers. Also call unconditionally TRACE_IRQS_ON when leaving interrupts handlers. This leaves the special psw_idle() case, which now returns with interrupts disabled, but has an "irqs on" lockdep state. So callers of psw_idle() must adjust the state on their own, if required. This is currently only __udelay_disabled(). Fixes: 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: add debug user asce supportHeiko Carstens
Verify on exit to user space that always - the primary ASCE (cr1) is set to kernel ASCE - the secondary ASCE (cr7) is set to user ASCE If this is not the case: panic since something went terribly wrong. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: remove set_fs / rework address space handlingHeiko Carstens
Remove set_fs support from s390. With doing this rework address space handling and simplify it. As a result address spaces are now setup like this: CPU running in | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE ----------------------------|-----------|-----------|----------- user space | user | user | kernel kernel, normal execution | kernel | user | kernel kernel, kvm guest execution | gmap | user | kernel To achieve this the getcpu vdso syscall is removed in order to avoid secondary address mode and a separate vdso address space in for user space. The getcpu vdso syscall will be implemented differently with a subsequent patch. The kernel accesses user space always via secondary address space. This happens in different ways: - with mvcos in home space mode and directly read/write to secondary address space - with mvcs/mvcp in primary space mode and copy from primary space to secondary space or vice versa - with e.g. cs in secondary space mode and access secondary space Switching translation modes happens with sacf before and after instructions which access user space, like before. Lazy handling of control register reloading is removed in the hope to make everything simpler, but at the cost of making kernel entry and exit a bit slower. That is: on kernel entry the primary asce is always changed to contain the kernel asce, and on kernel exit the primary asce is changed again so it contains the user asce. In kernel mode there is only one exception to the primary asce: when kvm guests are executed the primary asce contains the gmap asce (which describes the guest address space). The primary asce is reset to kernel asce whenever kvm guest execution is interrupted, so that this doesn't has to be taken into account for any user space accesses. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23Merge branch 'fixes' into featuresHeiko Carstens
* fixes: s390: fix fpu restore in entry.S Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390: fix fpu restore in entry.SSven Schnelle
We need to disable interrupts in load_fpu_regs(). Otherwise an interrupt might come in after the registers are loaded, but before CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns, CIF_FPU will be cleared and the registers will never be restored. The entry.S code usually saves the interrupt state in __SF_EMPTY on the stack when disabling/restoring interrupts. sie64a however saves the pointer to the sie control block in __SF_SIE_CONTROL, which references the same location. This is non-obvious to the reader. To avoid thrashing the sie control block pointer in load_fpu_regs(), move the __SIE_* offsets eight bytes after __SF_EMPTY on the stack. Cc: <stable@vger.kernel.org> # 5.8 Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Reported-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20s390: add separate program check exit pathHeiko Carstens
System call and program check handler both use the system call exit path when returning to previous context. However the program check handler jumps right to the end of the system call exit path if the previous context is kernel context. This lead to the quite odd double disabling of interrupts in the system call exit path introduced with commit ce9dfafe29be ("s390: fix system call exit path"). To avoid that have a separate program check handler exit path if the previous context is kernel context. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-09s390: add support for TIF_NOTIFY_SIGNALJens Axboe
Wire up TIF_NOTIFY_SIGNAL handling for s390. Cc: linux-s390@vger.kernel.org Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-09s390: fix system call exit pathHeiko Carstens
The system call exit path is running with interrupts enabled while checking for TIF/PIF/CIF bits which require special handling. If all bits have been checked interrupts are disabled and the kernel exits to user space. The problem is that after checking all bits and before interrupts are disabled bits can be set already again, due to interrupt handling. This means that the kernel can exit to user space with some TIF/PIF/CIF bits set, which should never happen. E.g. TIF_NEED_RESCHED might be set, which might lead to additional latencies, since that bit will only be recognized with next exit to user space. Fix this by checking the corresponding bits only when interrupts are disabled. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Acked-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-26s390: convert to GENERIC_VDSOSven Schnelle
Convert s390 to generic vDSO. There are a few special things on s390: - vDSO can be called without a stack frame - glibc did this in the past. So we need to allocate a stackframe on our own. - The former assembly code used stcke to get the TOD clock and applied time steering to it. We need to do the same in the new code. This is done in the architecture specific __arch_get_hw_counter function. The steering information is stored in an architecure specific area in the vDSO data. - CPUCLOCK_VIRT is now handled with a syscall fallback, which might be slower/less accurate than the old implementation. The getcpu() function stays as an assembly function because there is no generic implementation and the code is just a few lines. Performance number from my system do 100 mio gettimeofday() calls: Plain syscall: 8.6s Generic VDSO: 1.3s old ASM VDSO: 1s So it's a bit slower but still much faster than syscalls. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-07-10s390: fix comment regarding interrupts in svcChristian Borntraeger
With the removal of the critical section cleanup, we now enter the svc interrupt handler with interrupts disabled. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-06-23s390: fix system call single steppingSven Schnelle
When single stepping an svc instruction on s390, the kernel is entered with a PER program check interruption. The program check handler than jumps to the system call handler by reloading the PSW. The code didn't set GPR13 to the thread pointer in struct task_struct. This made the kernel access invalid memory while trying to fetch the syscall function address. Fix this by always assigned GPR13 after .Lsysc_per. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2020-06-16s390/ptrace: pass invalid syscall numbers to tracingSven Schnelle
tracing expects to see invalid syscalls, so pass it through. The syscall path in entry.S checks the syscall number before looking up the handler, so it is still safe. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-28s390: remove critical section cleanup from entry.SSven Schnelle
The current code is rather complex and caused a lot of subtle and hard to debug bugs in the past. Simplify the code by calling the system_call handler with interrupts disabled, save machine state, and re-enable them later. This requires significant changes to the machine check handling code as well. When the machine check interrupt arrived while being in kernel mode the new code will signal pending machine checks with a SIGP external call. When userspace was interrupted, the handler will switch to the kernel stack and directly execute s390_handle_mcck(). Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-03-10s390: prevent leaking kernel address in BEARSven Schnelle
When userspace executes a syscall or gets interrupted, BEAR contains a kernel address when returning to userspace. This make it pretty easy to figure out where the kernel is mapped even with KASLR enabled. To fix this, add lpswe to lowcore and always execute it there, so userspace sees only the lowcore address of lpswe. For this we have to extend both critical_cleanup and the SWITCH_ASYNC macro to also check for lpswe addresses in lowcore. Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: <stable@vger.kernel.org> # v5.2+ Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-08sched/rt, s390: Use CONFIG_PREEMPTIONThomas Gleixner
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 <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: linux-s390@vger.kernel.org Link: https://lore.kernel.org/r/20191015191821.11479-18-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-07s390: enforce CONFIG_SMPHeiko Carstens
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 <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-05-02s390: add missing ENDPROC statements to assembler functionsMartin Schwidefsky
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 <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: convert SYSCALL and PGM_CHECK handlers to .quadGerald Schaefer
With a relocatable kernel that could reside at any place in memory, the storage size for the SYSCALL and PGM_CHECK handlers needs to be increased from .long to .quad. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-01-18s390: autogenerate compat syscall wrappersArnd Bergmann
Any system call that takes a pointer argument on s390 requires a wrapper function to do a 31-to-64 zero-extension, these are currently generated in arch/s390/kernel/compat_wrapper.c. On arm64 and x86, we already generate similar wrappers for all system calls in the place of their definition, just for a different purpose (they load the arguments from pt_regs). We can do the same thing here, by adding an asm/syscall_wrapper.h file with a copy of all the relevant macros to override the generic version. Besides the addition of the compat entry point, these also rename the entry points with a __s390_ or __s390x_ prefix, similar to what we do on arm64 and x86. This in turn requires renaming a few things, and adding a proper ni_syscall() entry point. In order to still compile system call definitions that pass an loff_t argument, the __SC_COMPAT_CAST() macro checks for that and forces an -ENOSYS error, which was the best I could come up with. Those functions must obviously not get called from user space, but instead require hand-written compat_sys_*() handlers, which fortunately already exist. Link: https://lore.kernel.org/lkml/20190116131527.2071570-5-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> [heiko.carstens@de.ibm.com: compile fix for !CONFIG_COMPAT] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-11-02s390/kasan: increase instrumented stack size to 64kVasily Gorbik
Increase kasan instrumented kernel stack size from 32k to 64k. Other architectures seems to get away with just doubling kernel stack size under kasan, but on s390 this appears to be not enough due to bigger frame size. The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting stack overflow is fs sync on xfs filesystem: #0 [9a0681e8] 704 bytes check_usage at 34b1fc #1 [9a0684a8] 432 bytes check_usage at 34c710 #2 [9a068658] 1048 bytes validate_chain at 35044a #3 [9a068a70] 312 bytes __lock_acquire at 3559fe #4 [9a068ba8] 440 bytes lock_acquire at 3576ee #5 [9a068d60] 104 bytes _raw_spin_lock at 21b44e0 #6 [9a068dc8] 1992 bytes enqueue_entity at 2dbf72 #7 [9a069590] 1496 bytes enqueue_task_fair at 2df5f0 #8 [9a069b68] 64 bytes ttwu_do_activate at 28f438 #9 [9a069ba8] 552 bytes try_to_wake_up at 298c4c #10 [9a069dd0] 168 bytes wake_up_worker at 23f97c #11 [9a069e78] 200 bytes insert_work at 23fc2e #12 [9a069f40] 648 bytes __queue_work at 2487c0 #13 [9a06a1c8] 200 bytes __queue_delayed_work at 24db28 #14 [9a06a290] 248 bytes mod_delayed_work_on at 24de84 #15 [9a06a388] 24 bytes kblockd_mod_delayed_work_on at 153e2a0 #16 [9a06a3a0] 288 bytes __blk_mq_delay_run_hw_queue at 158168c #17 [9a06a4c0] 192 bytes blk_mq_run_hw_queue at 1581a3c #18 [9a06a580] 184 bytes blk_mq_sched_insert_requests at 15a2192 #19 [9a06a638] 1024 bytes blk_mq_flush_plug_list at 1590f3a #20 [9a06aa38] 704 bytes blk_flush_plug_list at 1555028 #21 [9a06acf8] 320 bytes schedule at 219e476 #22 [9a06ae38] 760 bytes schedule_timeout at 21b0aac #23 [9a06b130] 408 bytes wait_for_common at 21a1706 #24 [9a06b2c8] 360 bytes xfs_buf_iowait at fa1540 #25 [9a06b430] 256 bytes __xfs_buf_submit at fadae6 #26 [9a06b530] 264 bytes xfs_buf_read_map at fae3f6 #27 [9a06b638] 656 bytes xfs_trans_read_buf_map at 10ac9a8 #28 [9a06b8c8] 304 bytes xfs_btree_kill_root at e72426 #29 [9a06b9f8] 288 bytes xfs_btree_lookup_get_block at e7bc5e #30 [9a06bb18] 624 bytes xfs_btree_lookup at e7e1a6 #31 [9a06bd88] 2664 bytes xfs_alloc_ag_vextent_near at dfa070 #32 [9a06c7f0] 144 bytes xfs_alloc_ag_vextent at dff3ca #33 [9a06c880] 1128 bytes xfs_alloc_vextent at e05fce #34 [9a06cce8] 584 bytes xfs_bmap_btalloc at e58342 #35 [9a06cf30] 1336 bytes xfs_bmapi_write at e618de #36 [9a06d468] 776 bytes xfs_iomap_write_allocate at ff678e #37 [9a06d770] 720 bytes xfs_map_blocks at f82af8 #38 [9a06da40] 928 bytes xfs_writepage_map at f83cd6 #39 [9a06dde0] 320 bytes xfs_do_writepage at f85872 #40 [9a06df20] 1320 bytes write_cache_pages at 73dfe8 #41 [9a06e448] 208 bytes xfs_vm_writepages at f7f892 #42 [9a06e518] 88 bytes do_writepages at 73fe6a #43 [9a06e570] 872 bytes __writeback_single_inode at a20cb6 #44 [9a06e8d8] 664 bytes writeback_sb_inodes at a23be2 #45 [9a06eb70] 296 bytes __writeback_inodes_wb at a242e0 #46 [9a06ec98] 928 bytes wb_writeback at a2500e #47 [9a06f038] 848 bytes wb_do_writeback at a260ae #48 [9a06f388] 536 bytes wb_workfn at a28228 #49 [9a06f5a0] 1088 bytes process_one_work at 24a234 #50 [9a06f9e0] 1120 bytes worker_thread at 24ba26 #51 [9a06fe40] 104 bytes kthread at 26545a #52 [9a06fea8] kernel_thread_starter at 21b6b62 To be able to increase the stack size to 64k reuse LLILL instruction in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE (65192) value as unsigned. Reported-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09s390: add support for virtually mapped kernel stacksMartin Schwidefsky
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 <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-07-04s390: wire up rseq system callHeiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-25s390: Correct register corruption in critical section cleanupChristian Borntraeger
In the critical section cleanup we must not mess with r1. For march=z9 or older, larl + ex (instead of exrl) are used with r1 as a temporary register. This can clobber r1 in several interrupt handlers. Fix this by using r11 as a temp register. r11 is being saved by all callers of cleanup_critical. Fixes: 6dd85fbb87 ("s390: move expoline assembler macros to a header") Cc: stable@vger.kernel.org #v4.16 Reported-by: Oliver Kurz <okurz@suse.com> Reported-by: Petr Tesařík <ptesarik@suse.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-05-07s390: move expoline assembler macros to a headerMartin Schwidefsky
To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: - Improvements for the spectre defense: * The spectre related code is consolidated to a single file nospec-branch.c * Automatic enable/disable for the spectre v2 defenses (expoline vs. nobp) * Syslog messages for specve v2 are added * Enable CONFIG_GENERIC_CPU_VULNERABILITIES and define the attribute functions for spectre v1 and v2 - Add helper macros for assembler alternatives and use them to shorten the code in entry.S. - Add support for persistent configuration data via the SCLP Store Data interface. The H/W interface requires a page table that uses 4K pages only, the code to setup such an address space is added as well. - Enable virtio GPU emulation in QEMU. To do this the depends statements for a few common Kconfig options are modified. - Add support for format-3 channel path descriptors and add a binary sysfs interface to export the associated utility strings. - Add a sysfs attribute to control the IFCC handling in case of constant channel errors. - The vfio-ccw changes from Cornelia. - Bug fixes and cleanups. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (40 commits) s390/kvm: improve stack frame constants in entry.S s390/lpp: use assembler alternatives for the LPP instruction s390/entry.S: use assembler alternatives s390: add assembler macros for CPU alternatives s390: add sysfs attributes for spectre s390: report spectre mitigation via syslog s390: add automatic detection of the spectre defense s390: move nobp parameter functions to nospec-branch.c s390/cio: add util_string sysfs attribute s390/chsc: query utility strings via fmt3 channel path descriptor s390/cio: rename struct channel_path_desc s390/cio: fix unbind of io_subchannel_driver s390/qdio: split up CCQ handling for EQBS / SQBS s390/qdio: don't retry EQBS after CCQ 96 s390/qdio: restrict buffer merging to eligible devices s390/qdio: don't merge ERROR output buffers s390/qdio: simplify math in get_*_buffer_frontier() s390/decompressor: trim uncompressed image head during the build s390/crypto: Fix kernel crash on aes_s390 module remove. s390/defkeymap: fix global init to zero ...
2018-03-28s390/kvm: improve stack frame constants in entry.SMartin Schwidefsky
The code in sie64a uses the stack frame passed to the function to store some temporary data in the empty1 array (see struct stack_frame in asm/processor.h. Replace the __SF_EMPTY+x constants with a properly defined offset: s/__SF_EMPTY/__SF_SIE_CONTROL/, s/__SF_EMPTY+8/__SF_SIE_SAVEAREA/, s/__SF_EMPTY+16/__SF_SIE_REASON/, s/__SF_EMPTY+24/__SF_SIE_FLAGS/. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28s390/lpp: use assembler alternatives for the LPP instructionMartin Schwidefsky
With the new macros for CPU alternatives the MACHINE_FLAG_LPP check around the LPP instruction can be optimized. After this is done the flag can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28s390/entry.S: use assembler alternativesMartin Schwidefsky
Replace the open coded alternatives for the BPOFF, BPON, BPENTER, and BPEXIT macros with the new magic from asm/alternatives-asm.h to make the code easier to read. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-06s390/entry.S: fix spurious zeroing of r0Christian Borntraeger
when a system call is interrupted we might call the critical section cleanup handler that re-does some of the operations. When we are between .Lsysc_vtime and .Lsysc_do_svc we might also redo the saving of the problem state registers r0-r7: .Lcleanup_system_call: [...] 0: # update accounting time stamp mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER # set up saved register r11 lg %r15,__LC_KERNEL_STACK la %r9,STACK_FRAME_OVERHEAD(%r15) stg %r9,24(%r11) # r11 pt_regs pointer # fill pt_regs mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC ---> stmg %r0,%r7,__PT_R0(%r9) The problem is now, that we might have already zeroed out r0. The fix is to move the zeroing of r0 after sysc_do_svc. Reported-by: Farhan Ali <alifm@linux.vnet.ibm.com> Fixes: 7041d28115e91 ("s390: scrub registers on kernel entry and KVM exit") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-22s390: do not bypass BPENTER for interrupt system callsMartin Schwidefsky
The system call path can be interrupted before the switch back to the standard branch prediction with BPENTER has been done. The critical section cleanup code skips forward to .Lsysc_do_svc and bypasses the BPENTER. In this case the kernel and all subsequent code will run with the limited branch prediction. Fixes: eacf67eb9b32 ("s390: run user space and KVM guests with modified branch prediction") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-22s390/clean-up: use CFI_* macros in entry.SHendrik Brueckner
Commit f19fbd5ed642 ("s390: introduce execute-trampolines for branches") introduces .cfi_* assembler directives. Instead of using the directives directly, use the macros from asm/dwarf.h. This also ensures that the dwarf debug information are created in the .debug_frame section. Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-07s390: introduce execute-trampolines for branchesMartin Schwidefsky
Add CONFIG_EXPOLINE to enable the use of the new -mindirect-branch= and -mfunction_return= compiler options to create a kernel fortified against the specte v2 attack. With CONFIG_EXPOLINE=y all indirect branches will be issued with an execute type instruction. For z10 or newer the EXRL instruction will be used, for older machines the EX instruction. The typical indirect call basr %r14,%r1 is replaced with a PC relative call to a new thunk brasl %r14,__s390x_indirect_jump_r1 The thunk contains the EXRL/EX instruction to the indirect branch __s390x_indirect_jump_r1: exrl 0,0f j . 0: br %r1 The detour via the execute type instruction has a performance impact. To get rid of the detour the new kernel parameter "nospectre_v2" and "spectre_v2=[on,off,auto]" can be used. If the parameter is specified the kernel and module code will be patched at runtime. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05s390: run user space and KVM guests with modified branch predictionMartin Schwidefsky
Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary plumbing in entry.S to be able to run user space and KVM guests with limited branch prediction. To switch a user space process to limited branch prediction the s390_isolate_bp() function has to be call, and to run a vCPU of a KVM guest associated with the current task with limited branch prediction call s390_isolate_bp_guest(). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05s390: add options to change branch prediction behaviour for the kernelMartin Schwidefsky
Add the PPA instruction to the system entry and exit path to switch the kernel to a different branch prediction behaviour. The instructions are added via CPU alternatives and can be disabled with the "nospec" or the "nobp=0" kernel parameter. If the default behaviour selected with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be used to enable the changed kernel branch prediction. Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05s390: scrub registers on kernel entry and KVM exitMartin Schwidefsky
Clear all user space registers on entry to the kernel and all KVM guest registers on KVM guest exit if the register does not contain either a parameter or a result value. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23s390/syscalls: use generated syscall_table.h and unistd.h header filesHendrik Brueckner
Update the uapi/asm/unistd.h to include the generated compat and 64-bit version of the unistd.h and, as well as, the unistd_nr.h header file. Also remove the arch/s390/kernel/syscalls.S file and use the generated system call table, syscall_table.h, instead. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-20s390: rework __switch_to() to allow larger task_struct offsetsHeiko Carstens
If GCC_PLUGIN_RANDSTRUCT is enabled the members of task_struct will be shuffled around. The offsets of the "pid" and "stack" members within task_struct may not necessarily fit into 12 bits anymore, which causes compile errors within __switch_to, since instructions are used, which only have a 12 bit displacement field. Therefore rework __switch_to, to allow for larger offsets. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-14s390: remove all code using the access register modeMartin Schwidefsky
The vdso code for the getcpu() and the clock_gettime() call use the access register mode to access the per-CPU vdso data page with the current code. An alternative to the complicated AR mode is to use the secondary space mode. This makes the vdso faster and quite a bit simpler. The downside is that the uaccess code has to be changed quite a bit. Which instructions are used depends on the machine and what kind of uaccess operation is requested. The instruction dictates which ASCE value needs to be loaded into %cr1 and %cr7. The different cases: * User copy with MVCOS for z10 and newer machines The MVCOS instruction can copy between the primary space (aka user) and the home space (aka kernel) directly. For set_fs(KERNEL_DS) the kernel ASCE is loaded into %cr1. For set_fs(USER_DS) the user space is already loaded in %cr1. * User copy with MVCP/MVCS for older machines To be able to execute the MVCP/MVCS instructions the kernel needs to switch to primary mode. The control register %cr1 has to be set to the kernel ASCE and %cr7 to either the kernel ASCE or the user ASCE dependent on set_fs(KERNEL_DS) vs set_fs(USER_DS). * Data access in the user address space for strnlen / futex To use "normal" instruction with data from the user address space the secondary space mode is used. The kernel needs to switch to primary mode, %cr1 has to contain the kernel ASCE and %cr7 either the user ASCE or the kernel ASCE, dependent on set_fs. To load a new value into %cr1 or %cr7 is an expensive operation, the kernel tries to be lazy about it. E.g. for multiple user copies in a row with MVCP/MVCS the replacement of the vdso ASCE in %cr7 with the user ASCE is done only once. On return to user space a CPU bit is checked that loads the vdso ASCE again. To enable and disable the data access via the secondary space two new functions are added, enable_sacf_uaccess and disable_sacf_uaccess. The fact that a context is in secondary space uaccess mode is stored in the mm_segment_t value for the task. The code of an interrupt may use set_fs as long as it returns to the previous state it got with get_fs with another call to set_fs. The code in finish_arch_post_lock_switch simply has to do a set_fs with the current mm_segment_t value for the task. For CPUs with MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode, lazy | user | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | For CPUs without MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode lazy | kernel | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | The lines with "lazy" refer to the state after a copy via the secondary space with a delayed reload of %cr1 and %cr7. There are three hardware address spaces that can cause a DAT exception, primary, secondary and home space. The exception can be related to four different fault types: user space fault, vdso fault, kernel fault, and the gmap faults. Dependent on the set_fs state and normal vs. sacf mode there are a number of fault combinations: 1) user address space fault via the primary ASCE 2) gmap address space fault via the primary ASCE 3) kernel address space fault via the primary ASCE for machines with MVCOS and set_fs(KERNEL_DS) 4) vdso address space faults via the secondary ASCE with an invalid address while running in secondary space in problem state 5) user address space fault via the secondary ASCE for user-copy based on the secondary space mode, e.g. futex_ops or strnlen_user 6) kernel address space fault via the secondary ASCE for user-copy with secondary space mode with set_fs(KERNEL_DS) 7) kernel address space fault via the primary ASCE for user-copy with secondary space mode with set_fs(USER_DS) on machines without MVCOS. 8) kernel address space fault via the home space ASCE Replace user_space_fault() with a new function get_fault_type() that can distinguish all four different fault types. With these changes the futex atomic ops from the kernel and the strnlen_user will get a little bit slower, as well as the old style uaccess with MVCP/MVCS. All user accesses based on MVCOS will be as fast as before. On the positive side, the user space vdso code is a lot faster and Linux ceases to use the complicated AR mode. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-14s390/mm,kvm: improve detection of KVM guest faultsMartin Schwidefsky
The identification of guest fault currently relies on the PF_VCPU flag. This is set in guest_entry_irqoff and cleared in guest_exit_irqoff. Both functions are called by __vcpu_run, the PF_VCPU flag is set for quite a lot of kernel code outside of the guest execution. Replace the PF_VCPU scheme with the PIF_GUEST_FAULT in the pt_regs and make the program check handler code in entry.S set the bit only for exception that occurred between the .Lsie_gmap and .Lsie_done labels. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request for the v4.15 merge window this time from me. Besides a lot of cleanups and bug fixes these are the most important changes: - a new regset for runtime instrumentation registers - hardware accelerated AES-GCM support for the aes_s390 module - support for the new CEX6S crypto cards - support for FORTIFY_SOURCE - addition of missing z13 and new z14 instructions to the in-kernel disassembler - generate opcode tables for the in-kernel disassembler out of a simple text file instead of having to manually maintain those tables - fast memset16, memset32 and memset64 implementations - removal of named saved segment support - hardware counter support for z14 - queued spinlocks and queued rwlocks implementations for s390 - use the stack_depth tracking feature for s390 BPF JIT - a new s390_sthyi system call which emulates the sthyi (store hypervisor information) instruction - removal of the old KVM virtio transport - an s390 specific CPU alternatives implementation which is used in the new spinlock code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (88 commits) MAINTAINERS: add virtio-ccw.h to virtio/s390 section s390/noexec: execute kexec datamover without DAT s390: fix transactional execution control register handling s390/bpf: take advantage of stack_depth tracking s390: simplify transactional execution elf hwcap handling s390/zcrypt: Rework struct ap_qact_ap_info. s390/virtio: remove unused header file kvm_virtio.h s390: avoid undefined behaviour s390/disassembler: generate opcode tables from text file s390/disassembler: remove insn_to_mnemonic() s390/dasd: avoid calling do_gettimeofday() s390: vfio-ccw: Do not attempt to free no-op, test and tic cda. s390: remove named saved segment support s390/archrandom: Reconsider s390 arch random implementation s390/pci: do not require AIS facility s390/qdio: sanitize put_indicator s390/qdio: use atomic_cmpxchg s390/nmi: avoid using long-displacement facility s390: pass endianness info to sparse s390/decompressor: remove informational messages ...
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