summaryrefslogtreecommitdiffstats
path: root/arch/s390/mm/fault.c
Commit message (Collapse)AuthorAgeFilesLines
* s390/mm,tlb: correct tlb flush on page table upgradeMartin Schwidefsky2013-11-041-37/+0
| | | | | | | | | | | | The IDTE instruction used to flush TLB entries for a specific address space uses the address-space-control element (ASCE) to identify affected TLB entries. The upgrade of a page table adds a new top level page table which changes the ASCE. The TLB entries associated with the old ASCE need to be flushed and the ASCE for the address space needs to be replaced synchronously on all CPUs which currently use it. The concept of a lazy ASCE update with an exception handler is broken. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: always run the kernel in home spaceMartin Schwidefsky2013-10-241-7/+2
| | | | | | | Simplify the uaccess code by removing the user_mode=home option. The kernel will now always run in the home space mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner2013-09-121-0/+2
| | | | | | | | | | | | | | | | | | | | Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/irq: rework irq subclass handlingHeiko Carstens2013-09-041-1/+1
| | | | | | | | | | | Let's not add a function for every external interrupt subclass for which we need reference counting. Just have two register/unregister functions which have a subclass parameter: void irq_subclass_register(enum irq_subclass subclass); void irq_subclass_unregister(enum irq_subclass subclass); Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390: delete __cpuinit usage from all s390 filesPaul Gortmaker2013-07-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/s390 uses of the __cpuinit macros from all C files. Currently s390 does not have any __CPUINIT used in assembly files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* s390/mm: protection exception PSW for aborted transactionMartin Schwidefsky2013-04-171-2/+7
| | | | | | | | | | | | Protection exception usually are suppressing and the fault handler needs to rewind the PSW by the instruction length to get the correct fault address. Except for protection exceptions while the CPU is in the middle of a transaction. The CPU stores the transaction abort PSW at the start of the transaction, if the transaction is aborted the PSW is already correct and may not be modified by the fault handler. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/irq: remove split irq fields from /proc/statHeiko Carstens2013-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | Now that irq sum accounting for /proc/stat's "intr" line works again we have the oddity that the sum field (first field) contains only the sum of the second (external irqs) and third field (I/O interrupts). The reason for that is that these two fields are already sums of all other fields. So if we would sum up everything we would count every interrupt twice. This is broken since the split interrupt accounting was merged two years ago: 052ff461c8427629aee887ccc27478fc7373237c "[S390] irq: have detailed statistics for interrupt types". To fix this remove the split interrupt fields from /proc/stat's "intr" line again and only have them in /proc/interrupts. This restores the old behaviour, seems to be the only sane fix and mimics a behaviour from other architectures where /proc/interrupts also contains more than /proc/stat's "intr" line does. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/ptrace: race of single stepping vs signal deliveryMartin Schwidefsky2012-11-231-6/+13
| | | | | | | | | | | | | | | | | | 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>
* s390/mm: keep fault_init() private to fault.cHeiko Carstens2012-11-231-4/+8
| | | | | | | | | | | Just convert fault_init() to an early initcall. That's still early enough since it only needs be called before user space processes get executed. No reason to externalize it. Also add the function to the init section and move the store_indication variable to the read_mostly section. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* readahead: fault retry breaks mmap file read random detectionShaohua Li2012-10-091-0/+1
| | | | | | | | | | | | | | | | | | | .fault now can retry. The retry can break state machine of .fault. In filemap_fault, if page is miss, ra->mmap_miss is increased. In the second try, since the page is in page cache now, ra->mmap_miss is decreased. And these are done in one fault, so we can't detect random mmap file access. Add a new flag to indicate .fault is tried once. In the second try, skip ra->mmap_miss decreasing. The filemap_fault state machine is ok with it. I only tested x86, didn't test other archs, but looks the change for other archs is obvious, but who knows :) Signed-off-by: Shaohua Li <shaohua.li@fusionio.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/exceptions: switch to relative exception table entriesHeiko Carstens2012-09-261-1/+1
| | | | | | | | | 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>
* s390/mm: rename addressing_mode to s390_user_modeHeiko Carstens2012-09-261-1/+1
| | | | | | | | | | | | | Renaming the globally visible variable "user_mode" to "addressing_mode" in order to fix a name clash was not a good idea. (Commit 37fe1d73 "s390/mm: rename user_mode variable to addressing_mode") Looking at the code after a couple of weeks one thinks: addressing mode of what? So rename the variable again. This time to s390_user_mode. Which hopefully makes more sense. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cpu hotplug: mask out CPU_TASKS_FROZEN in cu hotplug notifiersHeiko Carstens2012-09-261-2/+1
| | | | | | | | | Unify all our cpu hotplug notifiers to mask out the CPU_TASKS_FROZEN bit, so we don't have to add all the *_FROZEN variant cases to the notifiers. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: make use of user_mode() macro where possibleHeiko Carstens2012-07-301-4/+4
| | | | | | | | | We use the user_mode() helper already at several places but also have the open coded variant at other places. Convert the code to always use the helper function. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: rename user_mode variable to addressing_modeHeiko Carstens2012-07-301-1/+1
| | | | | | | Fix name clash with user_mode() define which is also used in common code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: fix fault handling for page table walk caseHeiko Carstens2012-07-301-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure the kernel does not incorrectly create a SIGBUS signal during user space accesses: For user space accesses in the switched addressing mode case the kernel may walk page tables and access user address space via the kernel mapping. If a page table entry is invalid the function __handle_fault() gets called in order to emulate a page fault and trigger all the usual actions like paging in a missing page etc. by calling handle_mm_fault(). If handle_mm_fault() returns with an error fixup handling is necessary. For the switched addressing mode case all errors need to be mapped to -EFAULT, so that the calling uaccess function can return -EFAULT to user space. Unfortunately the __handle_fault() incorrectly calls do_sigbus() if VM_FAULT_SIGBUS is set. This however should only happen if a page fault was triggered by a user space instruction. For kernel mode uaccesses the correct action is to only return -EFAULT. So user space may incorrectly see SIGBUS signals because of this bug. For current machines this would only be possible for the switched addressing mode case in conjunction with futex operations. Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: make page faults killableHeiko Carstens2012-07-301-1/+11
| | | | | | | This is the s390 variant of 37b23e05 "x86,mm: make pagefault killable". Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/comments: unify copyright messages and remove file namesHeiko Carstens2012-07-201-3/+1
| | | | | | | | | | | | | | 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>
* s390/pfault: add sanity checkHeiko Carstens2012-05-161-0/+3
| | | | | | | | | | | | If the task that was found on an initial interrupt doesn't match the current task execute a WARN_ON_ONCE() and don't put the task to sleep. When this happened something went wrong between the interface of the hypervisor and the kernel. In such a case keep the tasks alive to avoid a hanging system. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/pfault: use __set_task_stateHeiko Carstens2012-05-161-2/+2
| | | | | | | | Use __set_task_state() instead of set_task_state(). Saves a couple of instructions, since the memory barrier is not needed here. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/pfault: always search for task with reported pidHeiko Carstens2012-05-161-14/+10
| | | | | | | | Make the code a bit more symmetric and always search for the task of the reported pid. This simplifies the code a bit. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/pfault: fix task state raceHeiko Carstens2012-05-161-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | When setting the current task state to TASK_UNINTERRUPTIBLE this can race with a different cpu. The other cpu could set the task state after it inspected it (while it was still TASK_RUNNING) to TASK_RUNNING which would change the state from TASK_UNINTERRUPTIBLE to TASK_RUNNING again. This race was always present in the pfault interrupt code but didn't cause anything harmful before commit f2db2e6c "[S390] pfault: cpu hotplug vs missing completion interrupts" which relied on the fact that after setting the task state to TASK_UNINTERRUPTIBLE the task would really sleep. Since this is not necessarily the case the result may be a list corruption of the pfault_list or, as observed, a use-after-free bug while trying to access the task_struct of a task which terminated itself already. To fix this, we need to get a reference of the affected task when receiving the initial pfault interrupt and add special handling if we receive yet another initial pfault interrupt when the task is already enqueued in the pfault list. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> # needed for v3.0 and newer Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: replace TIF_SIE with PF_VCPUMartin Schwidefsky2012-05-161-1/+1
| | | | | | | 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>
* Disintegrate asm/system.h for S390David Howells2012-03-281-1/+1
| | | | | | | Disintegrate asm/system.h for S390. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-s390@vger.kernel.org
* [S390] irq: external interrupt code passingHeiko Carstens2012-03-111-2/+2
| | | | | | | | | | | | | | | The external interrupt handlers have a parameter called ext_int_code. Besides the name this paramter does not only contain the ext_int_code but in addition also the "cpu address" (POP) which caused the external interrupt. To make the code a bit more obvious pass a struct instead so the called function can easily distinguish between external interrupt code and cpu address. The cpu address field however is named "subcode" since some external interrupt sources do not pass a cpu address but a different parameter (or none at all). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* compat: fix compile breakage on s390Heiko Carstens2012-02-271-1/+0
| | | | | | | | | | | The new is_compat_task() define for the !COMPAT case in include/linux/compat.h conflicts with a similar define in arch/s390/include/asm/compat.h. This is the minimal patch which fixes the build issues. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [S390] cleanup trap handlingMartin Schwidefsky2011-12-271-55/+46
| | | | | | | | | | | | 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>
* [S390] disable MACHINE_IS_VM check for pfaultCarsten Otte2011-12-271-4/+2
| | | | | | | | | | This patch disables the check for MACHINE_IS_VM when initializing the pfault infrastructure. The code checks for successful completion of diag 258 anyway, thus it's safe to try initialization on LPAR anyway. This is needed to use pfault on kvm Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: ignore leftover completion interruptsHeiko Carstens2011-11-141-2/+7
| | | | | | | | | | | Ignore completion interrupts if the initial interrupt hasn't been received and the addressed task is not running. This case can only happen if leftover (pending) completion interrupt gets delivered which wasn't removed with the PFAULT CANCEL operation during cpu hotplug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] take mmap_sem when walking guest page tableCarsten Otte2011-10-301-1/+1
| | | | | | | | | | | | | | | gmap_fault needs to walk the guest page table. However, parts of that may change if some other thread does munmap. In that case gmap_unmap_notifier will also unmap the corresponding parts from the guest page table. We need to take mmap_sem in order to serialize these operations. do_exception now calls __gmap_fault with mmap_sem held which does not get exported to modules. The exported function, which is called from KVM, now takes mmap_sem. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup psw related bits and piecesMartin Schwidefsky2011-10-301-1/+1
| | | | | | | | | | Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] addressing mode limits and psw address wrappingMartin Schwidefsky2011-10-301-1/+1
| | | | | | | | | An instruction with an address right below the adress limit for the current addressing mode will wrap. The instruction restart logic in the protection fault handler and the signal code need to follow the wrapping rules to find the correct instruction address. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] kvm guest address space mappingMartin Schwidefsky2011-07-241-1/+17
| | | | | | | | | | | | | | | | | | Add code that allows KVM to control the virtual memory layout that is seen by a guest. The guest address space uses a second page table that shares the last level pte-tables with the process page table. If a page is unmapped from the process page table it is automatically unmapped from the guest page table as well. The guest address space mapping starts out empty, KVM can map any individual 1MB segments from the process virtual memory to any 1MB aligned location in the guest virtual memory. If a target segment in the process virtual memory does not exist or is unmapped while a guest mapping exists the desired target address is stored as an invalid segment table entry in the guest page table. The population of the guest page table is fault driven. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* perf: Remove the nmi parameter from the swevent and overflow interfacePeter Zijlstra2011-07-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nmi parameter indicated if we could do wakeups from the current context, if not, we would set some state and self-IPI and let the resulting interrupt do the wakeup. For the various event classes: - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from the PMI-tail (ARM etc.) - tracepoint: nmi=0; since tracepoint could be from NMI context. - software: nmi=[0,1]; some, like the schedule thing cannot perform wakeups, and hence need 0. As one can see, there is very little nmi=1 usage, and the down-side of not using it is that on some platforms some software events can have a jiffy delay in wakeup (when arch_irq_work_raise isn't implemented). The up-side however is that we can remove the nmi parameter and save a bunch of conditionals in fast paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Michael Cree <mcree@orcon.net.nz> Cc: Will Deacon <will.deacon@arm.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: Anton Blanchard <anton@samba.org> Cc: Eric B Munson <emunson@mgebm.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [S390] mm: add page fault retry handlingHeiko Carstens2011-05-261-13/+28
| | | | | | | s390 arch backend for d065bd81 "mm: retry page fault when blocking on disk transfer". Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] mm: handle kernel caused page fault oom situationsHeiko Carstens2011-05-261-7/+9
| | | | | | | | | | | | | | If e.g. copy_from_user() generates a page fault and the kernel runs into an OOM situation the system might lock up. If the OOM killer sends a SIG_KILL to the current process it can't handle it since it is stuck in a copy_from_user() - page fault loop. Fix this by adding the same fix as other architectures have. E.g. the x86 variant f86268 "x86/mm: Handle mm_fault_error() in kernel space" Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] irq: merge irq.c and s390_ext.cHeiko Carstens2011-05-261-1/+1
| | | | | | | | Merge irq.c and s390_ext.c into irq.c. That way all external interrupt related functions are together. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] irq: fix service signal external interrupt handlingHeiko Carstens2011-05-261-1/+1
| | | | | | | | | | | | | | | | | Interrupt sources like pfault, sclp, dasd_diag and virtio all use the service signal external interrupt subclass mask in control register 0 to enable and disable the corresponding interrupt. Because no reference counting is implemented each subsystem thinks it is the only user of subclass and sets and clears the bit like it wants. This leads to case that unloading the dasd diag module under z/VM causes both sclp and pfault interrupts to be masked. The result will be locked up system sooner or later. Fix this by introducing a new way to set (register) and clear (unregister) the service signal subclass mask bit in cr0. Also convert all drivers. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: always enable service signal interruptHeiko Carstens2011-05-261-2/+1
| | | | | | | | | Always enable the service signal subclass mask bit in cr0, if pfault is available. That way we use the normal cpu hotplug way to propagate the subclass mask bit in cr0 instead of open coding it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: cleanup codeHeiko Carstens2011-05-231-30/+37
| | | | | | | Small code cleanup. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: cpu hotplug vs missing completion interruptsHeiko Carstens2011-05-231-24/+65
| | | | | | | | | | | | | | | | | 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>
* [S390] Remove data execution protectionMartin Schwidefsky2011-05-231-39/+0
| | | | | | | | | | | | | | | | | | The noexec support on s390 does not rely on a bit in the page table entry but utilizes the secondary space mode to distinguish between memory accesses for instructions vs. data. The noexec code relies on the assumption that the cpu will always use the secondary space page table for data accesses while it is running in the secondary space mode. Up to the z9-109 class machines this has been the case. Unfortunately this is not true anymore with z10 and later machines. The load-relative-long instructions lrl, lgrl and lgfrl access the memory operand using the same addressing-space mode that has been used to fetch the instruction. This breaks the noexec mode for all user space binaries compiled with march=z10 or later. The only option is to remove the current noexec support. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] irqstats: fix counting of pfault, dasd diag and virtio irqsHeiko Carstens2011-04-291-1/+1
| | | | | | | | | | | | | pfault, dasd diag and virtio all use the same external interrupt number. The respective interrupt handlers decide by the subcode if they are meant to handle the interrupt. Counting is currently done before looking at the subcode which means each handler counts an interrupt even if it is not handling it. Fix this by moving the kstat code after the code which looks at the subcode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: fix token handlingHeiko Carstens2011-04-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | f6649a7e "[S390] cleanup lowcore access from external interrupts" changed handling of external interrupts. Instead of letting the external interrupt handlers accessing the per cpu lowcore the entry code of the kernel reads already all fields that are necessary and passes them to the handlers. The pfault interrupt handler was incorrectly converted. It tries to dereference a value which used to be a pointer to a lowcore field. After the conversion however it is not anymore the pointer to the field but its content. So instead of a dereference only a cast is needed to get the task pointer that caused the pfault. Fixes a NULL pointer dereference and a subsequent kernel crash: Unable to handle kernel pointer dereference at virtual kernel address (null) Oops: 0004 [#1] SMP Modules linked in: nfsd exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc loop qeth_l3 qeth vmur ccwgroup ext3 jbd mbcache dm_mod dasd_eckd_mod dasd_diag_mod dasd_mod CPU: 0 Not tainted 2.6.38-2-s390x #1 Process cron (pid: 1106, task: 000000001f962f78, ksp: 000000001fa0f9d0) Krnl PSW : 0404200180000000 000000000002c03e (pfault_interrupt+0xa2/0x138) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3 Krnl GPRS: 0000000000000000 0000000000000001 0000000000000000 0000000000000001 000000001f962f78 0000000000518968 0000000090000002 000000001ff03280 0000000000000000 000000000064f000 000000001f962f78 0000000000002603 0000000006002603 0000000000000000 000000001ff7fe68 000000001ff7fe48 Krnl Code: 000000000002c036: 5820d010 l %r2,16(%r13) 000000000002c03a: 1832 lr %r3,%r2 000000000002c03c: 1a31 ar %r3,%r1 >000000000002c03e: ba23d010 cs %r2,%r3,16(%r13) 000000000002c042: a744fffc brc 4,2c03a 000000000002c046: a7290002 lghi %r2,2 000000000002c04a: e320d0000024 stg %r2,0(%r13) 000000000002c050: 07f0 bcr 15,%r0 Call Trace: ([<000000001f962f78>] 0x1f962f78) [<000000000001acda>] do_extint+0xf6/0x138 [<000000000039b6ca>] ext_no_vtime+0x30/0x34 [<000000007d706e04>] 0x7d706e04 Last Breaking-Event-Address: [<0000000000000000>] 0x0 For stable maintainers: the first kernel which contains this bug is 2.6.37. Reported-by: Stephen Powell <zlinuxman@wowway.com> Cc: Jonathan Nieder <jrnieder@gmail.com> Cc: stable@kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* [S390] ptrace cleanupMartin Schwidefsky2011-01-051-3/+3
| | | | | | | Overhaul program event recording and the code dealing with the ptrace user space interface. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] pfault: delay register of pfault interruptHeiko Carstens2011-01-051-12/+15
| | | | | | | | | | Use an early init call to initialize pfault. That way it is possible to use the register_external_interrupt() instead of the early variant. No need to enable pfault any earlier since it has only effect if user space processes are running. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] irq: have detailed statistics for interrupt typesHeiko Carstens2011-01-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | Up to now /proc/interrupts only has statistics for external and i/o interrupts but doesn't split up them any further. This patch adds a line for every single interrupt source so that it is possible to easier tell what the machine is/was doing. Part of the output now looks like this; CPU0 CPU2 CPU4 EXT: 3898 4232 2305 I/O: 782 315 245 CLK: 1029 1964 727 [EXT] Clock Comparator IPI: 2868 2267 1577 [EXT] Signal Processor TMR: 0 0 0 [EXT] CPU Timer TAL: 0 0 0 [EXT] Timing Alert PFL: 0 0 0 [EXT] Pseudo Page Fault [...] NMI: 0 1 1 [NMI] Machine Checks Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup facility list handlingMartin Schwidefsky2010-10-251-6/+1
| | | | | | | Store the facility list once at system startup with stfl/stfle and reuse the result for all facility tests. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup lowcore access from external interruptsMartin Schwidefsky2010-10-251-3/+8
| | | | | | | 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>
OpenPOWER on IntegriCloud