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2011-02-15s390: remove task_show_regsMartin Schwidefsky
task_show_regs used to be a debugging aid in the early bringup days of Linux on s390. /proc/<pid>/status is a world readable file, it is not a good idea to show the registers of a process. The only correct fix is to remove task_show_regs. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12[S390] Randomize PIEsHeiko Carstens
Randomize ELF_ET_DYN_BASE, which is used when loading position independent executables. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-12[S390] Randomise the brk regionHeiko Carstens
Randomize heap address like other architectures do already. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-12[S390] Randomize lower bits of stack addressHeiko Carstens
Randomize the lower bits of the stack address like x86 and powerpc. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-12[S390] vdso: dont map at mmap_baseHeiko Carstens
The vdso object is currently always mapped with mm->mmap_base used as requested address. In case of flexible mmap layout this means it gets mapped above mmap_base and therefore potentially stealing a bit of address space that is reserved for the stack. In case of flexible mmap layout the object should be mapped below mmap base. For legacy mmap layout above. To fix this just don't request any specific address and let the mmap code figure out an address that fits. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] prevent unneccesary loops_per_jiffy recalculationHeiko Carstens
When the seqfile /proc/cpuinfo gets accesses for each possible cpu loops_per_jiffy gets recalculated. However its value is only needed on first access. In addition loops_per_jiffy should be recalculated when the machine reports a capability change. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] cpuinfo: use get_online_cpus() instead of preempt_disable()Heiko Carstens
Use get_online_cpus() instead of preempt_disable() to make sure cpus don't go offline while accessing their per cpu data. The preempt_disable() stuff is old code which was used before get_online_cpus() was available. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] smp: remove cpu hotplug messagesHeiko Carstens
Get rid of messages that indicate if a cpu went online or offline. There is nothing special about this anymore and these messages might flood the kernel log buffer which makes debugging harder since more important messages might be overwritten. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] cleanup ftrace backend functionsMartin Schwidefsky
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] smp/idle: call init_idle() before starting a new cpuHeiko Carstens
Call init_idle() which (re-)initializes the idle task structure before it gets used on a new cpu. That way we can also get rid of the odd preempt_enable_no_resched() call we have in the cpu offline path within cpu_idle(). That call prevented preempt count imbalances between cpu hotplug operations. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] smp: delay idle task creationHeiko Carstens
Delay idle task creation until a cpu gets set online instead of creating them for all possible cpus at system startup. For one cpu system this should safe more than 1 MB. On my debug system with lots of debug stuff enabled this saves 2 MB. Same as on x86. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] nmi: enable machine checks earlyHeiko Carstens
Until now machine checks for the swapper process of the IPL cpu are just implicitly (and more or less accidently) enabled when the first time the idle process goes into idle state and loads an enabled wait psw. Before that machine checks are disabled. So let's enable them explicitly in trap_init() so we have a well defined time when machine checks are enabled. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] 31 bit entry.S update.Martin Schwidefsky
Make the code in the 31 bit entry.S code as similar as possible to the 64 bit version in entry64.S. That makes it easier to add new code to the first level interrupt handler that affects both 31 and 64 bit kernels. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] extint: get rid of early code plus cleanupHeiko Carstens
Get rid of register/unregister_early_external_interrupt() and clean up the code while at it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] pfault: delay register of pfault interruptHeiko Carstens
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>
2011-01-05[S390] ap bus: add support for irq statisticsHolger Dengler
Add support for AP Bus I/O interrupt statistics in /proc/interrupts. Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com> Signed-off-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] ctc: add support for irq statisticsHeiko Carstens
Add support for CTC I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] claw: add support for irq statisticsHeiko Carstens
Add support for CLAW I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] lcs: add support for irq statisticsHeiko Carstens
Add support for LCS I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] vmur: add support for irq statisticsHeiko Carstens
Add support for VMUR I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] tape: add support for irq statisticsHeiko Carstens
Add support for ccw based tape I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] 3270: add support for irq statisticsHeiko Carstens
Add support for 3270 I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] 3215: add support for irq statisticsHeiko Carstens
Add support for 3215 I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: add support for irq statisticsHeiko Carstens
Add support for DASD I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] qdio: add qdio interrupts to interrupt statisticsJan Glauber
Count traditional qdio interrupts and adapter interrupts for qdio in the interrupt statistics. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] irq: have detailed statistics for interrupt typesHeiko Carstens
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>
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>
2011-01-05[S390] kprobes: coding styleMartin Schwidefsky
Correct some minor coding style issues. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: restructure handler functionMartin Schwidefsky
Restructure the kprobe breakpoint handler function. Add comments to make it more comprehensible and add a sanity check for re-entering kprobes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: jprobe save and restoreMartin Schwidefsky
Register %r14 and %r15 are already stored in jprobe_saved_regs, no need to store them a second time in jprobe_saved_r14 / jprobe_saved_r15. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: insn slotsMartin Schwidefsky
The s390 architecture can execute code on kmalloc/vmalloc memory. No need for the __ARCH_WANT_KPROBES_INSN_SLOT detour. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: activation and deactivationMartin Schwidefsky
Replace set_current_kprobe/reset_current_kprobe/save_previous_kprobe/ restore_previous_kprobe with a simpler scheme push_kprobe/pop_kprobe. The mini kprobes stack can store up to two active kprobes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: instruction fixupMartin Schwidefsky
Determine instruction fixup details in resume_execution, no need to do it beforehand. Remove fixup, ilen and reg from arch_specific_insn. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: instruction swapMartin Schwidefsky
Move the definition of the helper structure ins_replace_args to the only place where it is used and drop the old member as it is not needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: single step cleanupMartin Schwidefsky
The saved interrupt mask and the saved control registers are only relevant while single stepping is set up. A secondary kprobe while kprobe single stepping is active may not occur. That makes is safe to remove the save and restore of kprobe_saved_imask / kprobe_save_ctl from save_previous_kprobe and restore_previous_kprobe. Move all single step related code to two functions, enable_singlestep and disable_singlestep. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] kprobes: single stepped breakpointMartin Schwidefsky
Remove special case of a kprobe on a breakpoint while a relocated instruction is single stepped. The only instruction that may cause a fault while kprobe single stepping is active is the relocated instruction. There is no kprobe on the instruction slot retrieved with get_insn_slot(). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-12-01[S390] nohz/s390: fix arch_needs_cpu() return value on offline cpusHeiko Carstens
This fixes the same problem as described in the patch "nohz: fix printk_needs_cpu() return value on offline cpus" for the arch_needs_cpu() primitive: arch_needs_cpu() may return 1 if called on offline cpus. When a cpu gets offlined it schedules the idle process which, before killing its own cpu, will call tick_nohz_stop_sched_tick(). That function in turn will call arch_needs_cpu() in order to check if the local tick can be disabled. On offline cpus this function should naturally return 0 since regardless if the tick gets disabled or not the cpu will be dead short after. That is besides the fact that __cpu_disable() should already have made sure that no interrupts on the offlined cpu will be delivered anyway. In this case it prevents tick_nohz_stop_sched_tick() to call select_nohz_load_balancer(). No idea if that really is a problem. However what made me debug this is that on 2.6.32 the function get_nohz_load_balancer() is used within __mod_timer() to select a cpu on which a timer gets enqueued. If arch_needs_cpu() returns 1 then the nohz_load_balancer cpu doesn't get updated when a cpu gets offlined. It may contain the cpu number of an offline cpu. In turn timers get enqueued on an offline cpu and not very surprisingly they never expire and cause system hangs. This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses get_nohz_timer_target() which doesn't have that problem. However there might be other problems because of the too early exit tick_nohz_stop_sched_tick() in case a cpu goes offline. This specific bug was indrocuded with 3c5d92a0 "nohz: Introduce arch_needs_cpu". In this case a cpu hotplug notifier is used to fix the issue in order to keep the normal/fast path small. All we need to do is to clear the condition that makes arch_needs_cpu() return 1 since it is just a performance improvement which is supposed to keep the local tick running for a short period if a cpu goes idle. Nothing special needs to be done except for clearing the condition. Cc: stable@kernel.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-25[S390] nmi: fix clock comparator revalidationHeiko Carstens
On each machine check all registers are revalidated. The save area for the clock comparator however only contains the upper most seven bytes of the former contents, if valid. Therefore the machine check handler uses a store clock instruction to get the current time and writes that to the clock comparator register which in turn will generate an immediate timer interrupt. However within the lowcore the expected time of the next timer interrupt is stored. If the interrupt happens before that time the handler won't be called. In turn the clock comparator won't be reprogrammed and therefore the interrupt condition stays pending which causes an interrupt loop until the expected time is reached. On NOHZ machines this can result in unresponsive machines since the time of the next expected interrupted can be a couple of days in the future. To fix this just revalidate the clock comparator register with the expected value. In addition the special handling for udelay must be changed as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-10[S390] kprobes: Fix the return address of multiple kretprobesMartin Schwidefsky
Analog to git commit 737480a0d525dae13306296da08029dff545bc72 fix the return address of subsequent kretprobes when multiple kretprobes are set on the same function. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-10[S390] kprobes: disable interrupts throughoutMartin Schwidefsky
Execute the kprobe exception and fault handler with interrupts disabled. To disable the interrupts only while a single step is in progress is not good enough, a kprobe from interrupt context while another kprobe is handled can confuse the internal house keeping. 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>
2010-10-29[S390] vdso: get rid of redefinition warningsHeiko Carstens
The CLOCK_* defines in asm-offsets.c are only used for the vdso code however in the meantime they cause other trouble. Just rename them to get permanently rid of this: In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0, from arch/s390/mm/fault.c:33: include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined include/linux/time.h:286:0: note: this is the location of the previous definition include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined include/linux/time.h:287:0: note: this is the location of the previous definition Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] facility detection: remove unused variableHeiko Carstens
arch/s390/kernel/early.c: In function 'setup_hpage': arch/s390/kernel/early.c:285:15: warning: unused variable 'facilities' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] topology: fix cpu masks for topology=off caseHeiko Carstens
Fix cpu masks for 'topology=off' case. Folding of the scheduling domains happen in such a way that everything belongs to the MC domain instead of the CPU doimain. This should fix a performance regression introduced with eafd2b6d "[S390] topology: use default MC domain initializer" and also makes sure we have the same behavious as if CONFIG_SCHED_MC was not selected at all. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] topology: add SCHED_MC config optionHeiko Carstens
This allows us to easily check for performance differences seen with !CONFIG_SCHED_MC and topology=off. Actually there shouldn't be any (besides a small overhead because of additional code). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] Add z196 machine type to setup_hwcapsHeiko Carstens
Add machine type for zEnterprise 196 to elf platform detection. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-27ptrace: change signature of arch_ptrace()Namhyung Kim
Fix up the arguments to arch_ptrace() to take account of the fact that @addr and @data are now unsigned long rather than long as of a preceding patch in this series. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: <linux-arch@vger.kernel.org> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25[S390] topology: export cpu topology via proc/sysinfoHeiko Carstens
Export the cpu configuration topology via sysinfo. Two new lines are introduced: CPU Topology HW: 0 0 0 4 6 4 CPU Topology SW: 0 0 0 0 4 24 The HW line describes the cpu topology nesting levels when the maximum nesting level is used to get the corresponding SYSIB. The SW line describes what Linux is actually using. In this case it supports only two levels (CONFIG_SCHED_BOOK off) and therefore the hardware folded the two lower levels in the SYSIB response block. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>