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2013-03-05s390: critical section cleanup vs. machine checksMartin Schwidefsky
The current machine check code uses the registers stored by the machine in the lowcore at __LC_GPREGS_SAVE_AREA as the registers of the interrupted context. The registers 0-7 of a user process can get clobbered if a machine checks interrupts the execution of a critical section in entry[64].S. The reason is that the critical section cleanup code may need to modify the PSW and the registers for the previous context to get to the end of a critical section. If registers 0-7 have to be replaced the relevant copy will be in the registers, which invalidates the copy in the lowcore. The machine check handler needs to explicitly store registers 0-7 to the stack. Cc: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-14s390/cleanup: rename SPP to LPPHendrik Brueckner
The set-program-parameter (SPP) instruction has been renamed to load-program-parameter (LPP) (see SA23-2260). Reflect this change and rename all macro/instruction references. Also remove the duplicate SPP/LPP entry in the kernel disassembler instruction list. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 update from Martin Schwidefsky: "Add support to generate code for the latest machine zEC12, MOD and XOR instruction support for the BPF jit compiler, the dasd safe offline feature and the big one: the s390 architecture gets PCI support!! Right before the world ends on the 21st ;-)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits) s390/qdio: rename the misleading PCI flag of qdio devices s390/pci: remove obsolete email addresses s390/pci: speed up __iowrite64_copy by using pci store block insn s390/pci: enable NEED_DMA_MAP_STATE s390/pci: no msleep in potential IRQ context s390/pci: fix potential NULL pointer dereference in dma_free_seg_table() s390/pci: use kmem_cache_zalloc instead of kmem_cache_alloc/memset s390/bpf,jit: add support for XOR instruction s390/bpf,jit: add support MOD instruction s390/cio: fix pgid reserved check vga: compile fix, disable vga for s390 s390/pci: add PCI Kconfig options s390/pci: s390 specific PCI sysfs attributes s390/pci: PCI hotplug support via SCLP s390/pci: CHSC PCI support for error and availability events s390/pci: DMA support s390/pci: PCI adapter interrupts for MSI/MSI-X s390/bitops: find leftmost bit instruction support s390/pci: CLP interface s390/pci: base support ...
2012-11-23s390/kvm: Fix address space mixupChristian Borntraeger
I was chasing down a bug of random validity intercepts on s390. (guest prefix page not mapped in the host virtual aspace). Turns out that the problem was a wrong address space control element. The cause was quite complex: During paging activity a DAT protection during SIE caused a program interrupt. Normally, the sie retry loop tries to catch all interrupts during and shortly before sie to rerun the setup. The problem is now that protection causes a suppressing program interrupt, causing the PSW to point to the instruction AFTER SIE in case of DAT protection. This confused the logic of the retry loop to not trigger, instead we jumped directly back to SIE after return from the program interrupt. (the protection fault handler itself did a rewind of the psw). This usually works quite well, but: If now the protection fault handler has to wait, another program might be scheduled in. Later on the sie process will be schedules in again. In that case the content of CR1 (primary address space) will be wrong because switch_to will put the user space ASCE into CR1 and not the guest ASCE. In addition the program parameter is also wrong for every protection fault of a guest, since we dont issue the SPP instruction. So lets also check for PSW == instruction after SIE in the program check handler. Instead of expensively checking all program interruption codes that might be suppressing we assume that a program interrupt pointing after SIE was always a program interrupt in SIE. (Otherwise we have a kernel bug anyway). We also have to compensate the rewinding, since the C-level handlers will do that. Therefore we need to add a nop with the same length as SIE before the sie_loop. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> CC: stable@vger.kernel.org CC: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-11-23s390/ptrace: race of single stepping vs signal deliveryMartin Schwidefsky
The current single step code is racy in regard to concurrent delivery of signals. If a signal is delivered after a PER program check occurred but before the TIF_PER_TRAP bit has been checked in entry[64].S the code clears TIF_PER_TRAP and then calls do_signal. This is wrong, if the instruction completed (or has been suppressed) a SIGTRAP should be delivered to the debugger in any case. Only if the instruction has been nullified the SIGTRAP may not be send. The new logic always sets TIF_PER_TRAP if the program check indicates PER tracing but removes it again for all program checks that are nullifying. The effect is that for each change in the PSW address we now get a single SIGTRAP. Reported-by: Andreas Arnez <arnez@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-23s390/traps: preinitialize program check tableHeiko Carstens
Preinitialize the program check table, so we can put it into the read-only data section. Also use only four byte entries for the table, since each program check handler resides within the first 2GB. Therefore this reduces the size of the table by 50% on 64 bit builds. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-10-29s390: switch to saner kernel_execve() semanticsAl Viro
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull second s390 update from Martin Schwidefsky: "The big thing in this pull request is the UAPI patch from David, and worth mentioning is the page table dumper. The rest are small improvements and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/entry: fix svc number for TIF_SYSCALL system call restart s390/mm,vmem: fix vmem_add_mem()/vmem_remove_range() s390/vmalloc: have separate modules area s390/zcrypt: remove duplicated include from zcrypt_pcixcc.c s390/css_chars: remove superfluous ifdef s390/chsc: make headers usable s390/mm: let kernel text section always begin at 1MB s390/mm: fix mapping of read-only kernel text section s390/mm: add page table dumper s390: add support to start the kernel in 64 bit mode. s390/mm,pageattr: remove superfluous EXPORT_SYMBOLs s390/mm,pageattr: add more page table walk sanity checks s390/mm: fix pmd_huge() usage for kernel mapping s390/dcssblk: cleanup device attribute usage s390/mm: use pfmf instruction to initialize storage keys s390/facilities: cleanup PFMF and HPAGE machine facility detection UAPI: (Scripted) Disintegrate arch/s390/include/asm
2012-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
2012-10-09s390/entry: fix svc number for TIF_SYSCALL system call restartMartin Schwidefsky
The load of the svc number in the TIF_SYSCALL restart path needs to be done with an instruction that loads all 64 bits of %r1, 'lh' only loads 32 bits. If the upper half of %r1 is not zero and has the msb set, entry64.S will try to execute an svc with a really large number. What will be in the upper half of %r1 depends on the code generated by gcc for the functions on the do_signal() callchain. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-30s390: convert to generic kernel_execve()Al Viro
same situation as with alpha and arm - only massage needed Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30s390: fold kernel_thread_helper() into ret_from_fork()Al Viro
... and don't bother with syscall return path in case of kernel threads. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30s390: fold execve_tail() into start_thread(), convert to generic sys_execve()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26s390/exceptions: switch to relative exception table entriesHeiko Carstens
This is the s390 port of 70627654 "x86, extable: Switch to relative exception table entries". Reduces the size of our exception tables by 50% on 64 bit builds. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26s390: add support for transactional memoryMartin Schwidefsky
Allow user-space processes to use transactional execution (TX). If the TX facility is available user space programs can use transactions for fine-grained serialization based on the data objects that are referenced during a transaction. This is useful for lockless data structures and speculative compiler optimizations. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-20s390/vtimer: rework virtual timer interfaceMartin Schwidefsky
The current virtual timer interface is inherently per-cpu and hard to use. The sole user of the interface is appldata which uses it to execute a function after a specific amount of cputime has been used over all cpus. Rework the virtual timer interface to hook into the cputime accounting. This makes the interface independent from the CPU timer interrupts, and makes the virtual timers global as opposed to per-cpu. Overall the code is greatly simplified. The downside is that the accuracy is not as good as the original implementation, but it is still good enough for appldata. Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-20s390/comments: unify copyright messages and remove file namesHeiko Carstens
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-06-14s390/smp: make absolute lowcore / cpu restart parameter accesses more robustHeiko Carstens
Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-06-05s390/sigp: use sigp order code defines in assembly codeHeiko Carstens
Use sigp order code defines in assembly code as well. With this change all places that use sigp constants should have been converted to use self describing defines instead of directly using constants. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-06-05s390/kvm: get rid of duplicate instructionChristian Borntraeger
After commit 5e8010cb50d3de7202641c0088c211f7c9593ebc s390: replace TIF_SIE with PF_VCPU there is no need to load the thread info before sie_loop where it is also loaded. Get rid of this duplicate instruction. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390: fix race on TIF_MCCK_PENDINGMartin Schwidefsky
There is a small race window in the __switch_to code in regard to the transfer of the TIF_MCCK_PENDING bit from the previous to the next task. The bit is transferred before the task struct pointer and the thread-info pointer for the next task has been stored to lowcore. If a machine check sets the TIF_MCCK_PENDING bit between the transfer code and the store of current/thread_info the bit is still set for the previous task. And if the previous task has terminated it can get lost. The effect is that a pending CRW is not retrieved until the next machine checks sets TIF_MCCK_PENDING. To fix this reorder __switch_to to first store the task struct and thread-info pointer and then do the transfer of the bit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390/time: simply Kconfig dependencyHeiko Carstens
Use HAVE_MARCH_Z9_109_FEATURES to figure out if stckf is available at compile time. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390/entry64: avoid SPP code duplicationHeiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390/time: always use stckf instead of stck if availableHeiko Carstens
The store clock fast instruction saves a couple of instructions compared to the store clock instruction. Always use stckf instead of stck if it is available. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390: replace TIF_SIE with PF_VCPUMartin Schwidefsky
Replace the check for TIF_SIE in the fault handler by a check for PF_VCPU. With the last user of TIF_SIE gone we can now remove the bit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390: make sie intercept independent of thread_infoMartin Schwidefsky
HANDLE_SIE_INTERCEPT is called early, use supervisor state and instruction address to decide if the reset of the PSW to sie_loop is required. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390: initialize backchain for ext_int_handler()Michael Holzheu
To allow correct stack backtraces the backchain for the external interrupt handler is now initialized with zero like it is already done for example by io_int_handler(). Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] rework idle codeMartin Schwidefsky
Whenever the cpu loads an enabled wait PSW it will appear as idle to the underlying host system. The code in default_idle calls vtime_stop_cpu which does the necessary voodoo to get the cpu time accounting right. The udelay code just loads an enabled wait PSW. To correct this rework the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts to entry[64].S, vtime_stop_cpu can now be called from anywhere and vtime_start_cpu is gone. The correction of the cpu time during wakeup from an enabled wait PSW is done with a critical section in entry[64].S. As vtime_start_cpu is gone, s390_idle_check can be removed as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] rework smp codeMartin Schwidefsky
Define struct pcpu and merge some of the NR_CPUS arrays into it, including __cpu_logical_map, current_set and smp_cpu_state. Split smp related functions to those operating on physical cpus and the functions operating on a logical cpu number. Make the functions for physical cpus use a pointer to a struct pcpu. This hides the knowledge about cpu addresses in smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header. The PSW restart mechanism is used to start secondary cpus, calling a function on an online cpu, calling a function on the ipl cpu, and for the nmi signal. Replace the different assembler functions with a single function restart_int_handler. The new entry point calls a function whose pointer is stored in the lowcore of the target cpu and it can wait for the source cpu to stop. This covers all existing use cases. Overall the code is now simpler and there are ~380 lines less code. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] rename lowcore fieldMartin Schwidefsky
The 16 bit value at the lowcore location with offset 0x84 is the cpu address that is associated with an external interrupt. Rename the field from cpu_addr to ext_cpu_addr to make that clear. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] cleanup trap handlingMartin Schwidefsky
Move the program interruption code and the translation exception identifier to the pt_regs structure as 'int_code' and 'int_parm_long' and make the first level interrupt handler in entry[64].S store the two values. That makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct and to reduce the number of arguments to a lot of functions. Finally un-inline do_trap. Overall this saves 5812 bytes in the .text section of the 64 bit kernel. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] entry[64].S improvementsMartin Schwidefsky
Another round of cleanup for entry[64].S, in particular the program check handler looks more reasonable now. The code size for the 31 bit kernel has been reduced by 616 byte and by 528 byte for the 64 bit version. Even better the code is a bit faster as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] kvm: move cmf host id constant out of lowcoreMartin Schwidefsky
There is no reason for the cpu-measurement-facility host id constant to reside in the lowcore where space is precious. Use an entry in the literal pool in HANDLE_SIE_INTERCEPT and a stack slot in sie64a. While we are at it replace the id -1 with 0 to indicate host execution. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] load user asce on sie_faultCarsten Otte
On sie_fault we need to switch back to user ASCE. Otherwise we get interresting effects when exiting to "userspace" while the guest space is still active. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] add TIF_SYSCALL thread flagMartin Schwidefsky
Add an explicit TIF_SYSCALL bit that indicates if a task is inside a system call. The svc_code in the pt_regs structure is now only valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC can be replaced with TIF_SYSCALL. Overall do_signal is a bit more readable and it saves a few lines of code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] signal race with restarting system callsMartin Schwidefsky
For a ERESTARTNOHAND/ERESTARTSYS/ERESTARTNOINTR restarting system call do_signal will prepare the restart of the system call with a rewind of the PSW before calling get_signal_to_deliver (where the debugger might take control). For A ERESTART_RESTARTBLOCK restarting system call do_signal will set -EINTR as return code. There are two issues with this approach: 1) strace never sees ERESTARTNOHAND, ERESTARTSYS, ERESTARTNOINTR or ERESTART_RESTARTBLOCK as the rewinding already took place or the return code has been changed to -EINTR 2) if get_signal_to_deliver does not return with a signal to deliver the restart via the repeat of the svc instruction is left in place. This opens a race if another signal is made pending before the system call instruction can be reexecuted. The original system call will be restarted even if the second signal would have ended the system call with -EINTR. These two issues can be solved by dropping the early rewind of the system call before get_signal_to_deliver has been called and by using the TIF_RESTART_SVC magic to do the restart if no signal has to be delivered. The only situation where the system call restart via the repeat of the svc instruction is appropriate is when a SA_RESTART signal is delivered to user space. Unfortunately this breaks inferior calls by the debugger again. The system call number and the length of the system call instruction is lost over the inferior call and user space will see ERESTARTNOHAND/ ERESTARTSYS/ERESTARTNOINTR/ERESTART_RESTARTBLOCK. To correct this a new ptrace interface is added to save/restore the system call number and system call instruction length. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] lowcore cleanupMartin Schwidefsky
Remove the save_area_64 field from the 0xe00 - 0xf00 area in the lowcore. Use a free slot in the save_area array instead. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-09-20[S390] kvm: fix address mode switchingChristian Borntraeger
598841ca9919d008b520114d8a4378c4ce4e40a1 ([S390] use gmap address spaces for kvm guest images) changed kvm to use a separate address space for kvm guests. This address space was switched in __vcpu_run In some cases (preemption, page fault) there is the possibility that this address space switch is lost. The typical symptom was a huge amount of validity intercepts or random guest addressing exceptions. Fix this by doing the switch in sie_loop and sie_exit and saving the address space in the gmap structure itself. Also use the preempt notifier. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Avi Kivity <avi@redhat.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-08-03[S390] Add PSW restart shutdown triggerMichael Holzheu
With this patch a new S390 shutdown trigger "restart" is added. If under z/VM "systerm restart" is entered or under the HMC the "PSW restart" button is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded. Now we execute do_restart() that processes the restart action that is defined under /sys/firmware/shutdown_actions/on_restart. Currently the following actions are possible: reipl (default), stop, vmcmd, dump, and dump_reipl. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-07-24[S390] fix s390 assembler code alignmentsJan Glauber
The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24[S390] move sie code to entry.SMartin Schwidefsky
The entry to / exit from sie has subtle dependencies to the first level interrupt handler. Move the sie assembler code to entry64.S and replace the SIE_HOOK callback with a test and the new _TIF_SIE bit. In addition this patch fixes several problems in regard to the check for the_TIF_EXIT_SIE bits. The old code checked the TIF bits before executing the interrupt handler and it only modified the instruction address if it pointed directly to the sie instruction. In both cases it could miss a TIF bit that normally would cause an exit from the guest and would reenter the guest context. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23[S390] pfault: cpu hotplug vs missing completion interruptsHeiko Carstens
On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor which in turn will cancel all outstanding pfault requests that have been issued on that cpu (the same happens with a SIGP cpu reset). The result is that we end up with uninterruptible processes where the interrupt that would wake up these processes never arrives. In order to solve this all processes which wait for a pfault completion interrupt get woken up after a cpu hot remove. The worst case that could happen is that they fault again and in turn need to wait again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-10[S390] kernel: Initialize register 14 when starting new CPUMichael Holzheu
When starting a new CPU we currently jump to start_secondary() without setting register 14 (the return address) correctly. Therefore on the stack frame for start_secondary an invalid return address is stored. This leads to wrong stack back traces in kernel dumps. Example: #00 [1f33fe48] cpu_idle at 10614a #01 [1f33fe90] start_secondary at 54fa88 #02 [1f33feb8] (null) at 0 <--- invalid To fix this start_secondary() is called now with basr/brasl that sets register 14 correctly. The output of the stack backtrace looks then like the following: #00 [1f33fe48] cpu_idle at 10614a #01 [1f33fe90] start_secondary at 54fa88 #02 [1f33feb8] restart_base at 54f41e <--- correct Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] ptrace cleanupMartin Schwidefsky
Overhaul program event recording and the code dealing with the ptrace user space interface. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] add kprobes annotationsMartin Schwidefsky
Add kprobes annotations to get the massive 'probe kernel.function("*") {}' stress test working. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] fix kprobes single steppingMartin Schwidefsky
Fix kprobes after git commit 1e54622e0403891b10f2105663e0f9dd595a1f17 broke it. The kprobe_handler is now called with interrupts in the state at the time of the breakpoint. The single step of the replaced instruction is done with interrupts off which makes it necessary to enable and disable the interupts in the kprobes code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] cleanup system call parameter setupMartin Schwidefsky
Do the setup of the stack overflow argument for the sixth system call parameter right before the branch to the system call function. That simplifies the system call parameter access code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] cleanup lowcore access from external interruptsMartin Schwidefsky
Read external interrupts parameters from the lowcore in the first level interrupt handler in entry[64].S. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] cleanup lowcore access from program checksMartin Schwidefsky
Read all required fields for program checks from the lowcore in the first level interrupt handler in entry[64].S. If the context that caused the fault was enabled for interrupts we can now re-enable the irqs in entry[64].S. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-07-27[S390] Fix IRQ tracing in case of PERHeiko Carstens
In case user space is single stepped (PER) the program check handler claims too early that IRQs are enabled on the return path. Subsequent checks will notice that the IRQ mask in the PSW and what lockdep thinks the IRQ mask should be do not correlate and therefore will print a warning to the console and disable lockdep. Fix this by doing all the work within the correct context. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>