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* [S390] Clean up smp code in preparation for some larger changes.Heiko Carstens2007-04-271-161/+100
| | | | | Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Switch etr from tasklet to workqueue.Martin Schwidefsky2007-04-271-17/+17
| | | | | | | | | The clock synchronization of the ETR code requires an smp_call_function to synchronize all cpus. Calling smp_call_function from a tasklet is illegal. Replace the tasklet with a job on the global workqueue. ETR work is rare and can be postponed to a be done by a kernel thread. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Processor degradation notification.Heiko Carstens2007-04-271-5/+43
| | | | | | | | | Generate uevents for all cpus if cpu capability changes. This can happen e.g. because the cpus are overheating. The cpu capability can be read via /sys/devices/system/cpu/cpuN/capability. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] vtime: cleanup per_cpu usage.Jan Glauber2007-04-271-9/+7
| | | | | | | | Replace per_cpu(... , smp_processor_id()) with __get_cpu_var() Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] zfcpdump support.Michael Holzheu2007-04-274-86/+318
| | | | | | | | | | | | | | s390 machines provide hardware support for creating Linux dumps on SCSI disks. For creating a dump a special purpose dump Linux is used. The first 32 MB of memory are saved by the hardware before the dump Linux is booted. Via an SCLP interface, the saved memory can be accessed from Linux. This patch exports memory and registers of the crashed Linux to userspace via a debugfs file. For more information refer to Documentation/s390/zfcpdump.txt, which is included in this patch. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Use generic bug.Heiko Carstens2007-04-273-5/+26
| | | | | | | | | | | | Generic bug implementation for s390. Will increase the value of the console output on BUG() statements since registers r0-r5,r14 will not be clobbered by a printk() call that was previously done before the illegal instruction of BUG() was hit. Also implements an architecture specific WARN_ON(). Output of that could be increased but requires common code change. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Improved oops output.Martin Schwidefsky2007-04-273-39/+1296
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds two improvements to the oops output. First it adds an additional line after the PSW which decodes the different fields of it. Second a disassembler is added that decodes the instructions surrounding the faulting PSW. The output of a test oops now looks like this: kernel BUG at init/main.c:419 illegal operation: 0001 [#1] CPU: 0 Not tainted Process swapper (pid: 0, task: 0000000000464968, ksp: 00000000004be000) Krnl PSW : 0700000180000000 00000000000120b6 (rest_init+0x36/0x38) R:0 T:1 IO:1 EX:1 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 EA:3 Krnl GPRS: 0000000000000003 00000000004ba017 0000000000000022 0000000000000001 000000000003a5f6 0000000000000000 00000000004be6a8 0000000000000000 0000000000000000 00000000004b8200 0000000000003a50 0000000000008000 0000000000516368 000000000033d008 00000000000120b2 00000000004bdee0 Krnl Code: 00000000000120a6: e3e0f0980024 stg %r14,152(%r15) 00000000000120ac: c0e500014296 brasl %r14,3a5d8 00000000000120b2: a7f40001 brc 15,120b4 >00000000000120b6: 0707 bcr 0,%r7 00000000000120b8: eb7ff0500024 stmg %r7,%r15,80(%r15) 00000000000120be: c0d000195825 larl %r13,33d108 00000000000120c4: a7f13f00 tmll %r15,16128 00000000000120c8: a7840001 brc 8,120ca Call Trace: ([<00000000000120b2>] rest_init+0x32/0x38) [<00000000004be614>] start_kernel+0x37c/0x410 [<0000000000012020>] _ehead+0x20/0x80 Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] System call cleanup.Martin Schwidefsky2007-04-278-225/+162
| | | | | | | | | | | Remove system call glue for sys_clone, sys_fork, sys_vfork, sys_execve, sys_sigreturn, sys_rt_sigreturn and sys_sigaltstack. Call do_execve from kernel_execve directly, move pt_regs to the right place and branch to sysc_return to start the user space program. This removes the last in-kernel system call. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] cio/ipl: Clean interface between cio and ipl code.Heiko Carstens2007-04-271-1/+22
| | | | | | | Clean interface between cio and ipl code, so Peter stops complaining. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] memory detection: stop at first memory hole.Heiko Carstens2007-04-271-4/+3
| | | | | | | | If both sclp and diag memory detection don't work stop at the first memory hole. Otherwise the code might loop forever... Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] kprobes: Align probe address.David Wilder2007-03-261-1/+1
| | | | | | | | | | | | | | | Running a probe on s390 with a probe address that is not 4 byte aligned results in a Kernel BUG. The problem is that the stura instruction used by swap_instruction requires the destination address to be 4 byte aligned. As stura only writes 4 bytes, aligning to the next 4 byte aligned address results in the breakpoint instruction being stored past the probe address. The fix is to align the address backward (to the previous 4 byte aligned address) and writing the two byte breakpoint instruction in the appropriate bytes. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Wire up sys_utimes.Heiko Carstens2007-03-192-0/+7
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] reboot from and dump to SCSI under z/VM fails.Michael Holzheu2007-03-191-5/+4
| | | | | | | | | We used wrong length values for ipl and dump hardware structures. Since z/VM checks the ipl parameters more accurately than LPAR, the operations fail there. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Wire up compat_sys_epoll_pwait.Heiko Carstens2007-03-192-1/+12
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] strlcpy is smart enoughJean Delvare2007-03-191-1/+1
| | | | | | | | | strlcpy already accounts for the trailing zero in its length computation, so there is no need to substract one to the buffer size. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] memory detection: fix off by one bug.Heiko Carstens2007-03-191-2/+8
| | | | | | | | | | | diag 260 returns the address of the last addressable byte and not the size of memory. Since we want the size we have to add 1 to the return value. Disable diag 260 for non z/Arch mode since it doesn't work there anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fixed handling of access register mode faults.Gerald Schaefer2007-03-052-6/+16
| | | | | | | | | | | | | | | | | | | Replaced check_user_space() + __check_access_register with the new check_space(). The old functions made wrong assumptions about kernel and user space when the kernel and user address spaces are switched (kernel in home space, user in primary/secondary space). Secondly the user process can switch to the accress register mode if it is running in primary or secondary mode. In addition it can load an arbitrary value to the access registers. If any other value than 0 for primary space or 1 for secondary space is loaded and memory is accessed using the base register related to the access register, the program should be terminated with a SIGSEGV. To achieve that the DUALD pointer in the DUCT and the PSALD pointer in the PASTE need to point to an array of 8 invalid access-list entries to get a ALEN-translation exception if an invalid alet is used. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] nss: disable kexec.Heiko Carstens2007-03-051-0/+5
| | | | | | | | nss and kexec don't work together since kexec wants to write to the read-only text section of the shared kernel image. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] reipl: move dump_prefix_page out of text section.Heiko Carstens2007-03-053-12/+18
| | | | | | | | | | | Reipl doesn't work on older machines were s390_reset_machine() gets called. The reason is that the text section is read-only but the variable dump_prefix_page is there. Since s390_reset_machine() writes to it we get a protection exception. Therefore move dump_prefix_page to the bss section. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] smp: disable preemption in smp_call_function/smp_call_function_onHeiko Carstens2007-03-051-7/+8
| | | | | | | | | | Avoid sprinkling a _lot_ of preempt_disable/preempt_enable pairs. This would be necessary for e.g. the iucv driver. Also this way we are more consistent with other architectures which disable preemption at least for smp_call_function. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] kprobes breaks BUG_ONMartin Schwidefsky2007-03-051-14/+7
| | | | | | | | | | | | The illegal operation handler calls the die notifier with DIE_BPT to let kprobes pick up its breakpoint. If kprobes does not find its breakpoint it returns NOTIFY_STOP instead of NOTIFY_DONE. Since we use stop_machine_run on s390 to arm/disarm the kprobes breakpoints the race that kprobe_handler tries to solve by checking for the kprobes breakpoints does not exist. Removing the check makes BUG_ON working again. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] nss: Free unused memory in kernel image.Heiko Carstens2007-02-214-28/+17
| | | | | | | | | | With CONFIG_SHARED_KERNEL the kernel text segment that might be in a read only memory sections starts at 1MB. Memory between 0x12000 and 0x100000 is unused then. Free this, so we have appr. an extra MB of memory available. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] bss section clearing.Heiko Carstens2007-02-211-1/+1
| | | | | | | | Clear only memory from __bss_start to __bss_stop when clearing the bss section. Not until _end, which currently happens to be the same. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Remove BUG() statementMichael Holzheu2007-02-211-1/+1
| | | | | | | | To avoid ugly warings for older gccs, we replace BUG() with "return NULL", which is just as well. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] New header file ipl.hMichael Holzheu2007-02-214-22/+5
| | | | | | | | | Setup.h has been misused for ipl related stuff in the past. We now move everything, which has to do with ipl and reipl to a new header file named "ipl.h". Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] New get_cpu_id() inline assemblyMichael Holzheu2007-02-212-2/+2
| | | | | | | Replace two stidp inline assemblies with one global implementation. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] etr: Add barrier() to etr_sync_cpu_start().Heiko Carstens2007-02-211-1/+9
| | | | | | | | | | Force reading of *in_sync in while loop. Loops where the content that is checked for is changed by a different cpu always should have some sort of barrier() semantics. Otherwise this might lead to very subtle bugs. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] smp_call_function cleanupJan Glauber2007-02-211-104/+77
| | | | | | | | | | | | Introduce __smp_call_function_map which calls a function on all cpus given with a cpumask_t. Use it to implement smp_call_function and smp_call_function_on. Replace smp_ext_bitcall_others with smp_ext_bitcall and a for_each_cpu_mask loop. Use a cpumask_t instead of an atomic_t for cpu counting and print a warning if preempt is on in __smp_call_function_map(). Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [PATCH] clocksource: fixup is_continous changes on S390Thomas Gleixner2007-02-161-1/+1
| | | | | | | | | | | | Fixup the is_contionous replacement by a flag field. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: remove insert_at_head from register_sysctlEric W. Biederman2007-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The semantic effect of insert_at_head is that it would allow new registered sysctl entries to override existing sysctl entries of the same name. Which is pain for caching and the proc interface never implemented. I have done an audit and discovered that none of the current users of register_sysctl care as (excpet for directories) they do not register duplicate sysctl entries. So this patch simply removes the support for overriding existing entries in the sys_sysctl interface since no one uses it or cares and it makes future enhancments harder. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@muc.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Corey Minyard <minyard@acm.org> Cc: Neil Brown <neilb@suse.de> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Jan Kara <jack@ucw.cz> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: David Chinner <dgc@sgi.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: s390: remove unnecessary use of insert_at_headEric W. Biederman2007-02-141-1/+1
| | | | | | | Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: s390: move sysctl definitions to sysctl.hEric W. Biederman2007-02-141-1/+0
| | | | | | | | | | We need to have the the definition of all top level sysctl directories registers in sysctl.h so we don't conflict by accident and cause abi problems. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds2007-02-121-6/+9
|\ | | | | | | | | | | | | | | * 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: [S390] remove __io_virt and mmiowb. [S390] cio: use ARRAY_SIZE in device_id.c [S390] cio: Fixup interface for setting options on ccw devices. [S390] smp_call_function/smp_call_function_on locking.
| * [S390] smp_call_function/smp_call_function_on locking.Heiko Carstens2007-02-121-6/+9
| | | | | | | | | | | | | | | | | | | | smp_call_function and smp_call_function_on share the same lock and smp_call_function_on disables softirq's so it can be called from softirq context as well. Hence smp_call_function muss disable softirqs as well to avoid deadlocks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | [PATCH] mark struct file_operations const 2Arjan van de Ven2007-02-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. [akpm@osdl.org: sparc64 fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | [PATCH] Dynamic kernel command-line: s390Alon Bar-Lev2007-02-121-1/+1
|/ | | | | | | | | | Rename saved_command_line into boot_command_line. Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Common compat_sys_sysinfoKyle McMartin2007-02-113-49/+4
| | | | | | | | | | | | | | | | I noticed that almost all architectures implemented exactly the same sys32_sysinfo... except parisc, where a bug was to be found in handling of the uptime. So let's remove a whole whack of code for fun and profit. Cribbed compat_sys_sysinfo from x86_64's implementation, since I figured it would be the best tested. This patch incorporates Arnd's suggestion of not using set_fs/get_fs, but instead extracting out the common code from sys_sysinfo. Cc: Christoph Hellwig <hch@infradead.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] disable init/initramfs.c: architecturesJean-Paul Saman2007-02-111-0/+3
| | | | | | | | | | | | Update all arch/*/kernel/vmlinux.lds.S to not include space for initramfs when CONFIG_BLK_DEV_INITRAMFS is not selected. This saves another 4 kbytes on most platfoms (some reserve PAGE_SIZE for initramfs). Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [S390] Avoid excessive inlining.Heiko Carstens2007-02-056-17/+17
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Mark kernel text section read-only.Heiko Carstens2007-02-053-6/+25
| | | | | | | | | | | Set read-only flag in the page table entries for the kernel image text section. This will catch all instruction caused corruptions withing the text section. Instruction replacement via kprobes still works, since it bypasses now dynamic address translation. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Convert memory detection into C code.Heiko Carstens2007-02-058-570/+467
| | | | | | | | | | | | | | Hopefully this will make it more maintainable and less error prone. Code makes use of search_exception_tables(). Since it calls this function before the kernel exeception table is sorted, there is an early call to sort_main_extable(). This way it's easy to use the already present infrastructure of fixup sections. Also this would allows to easily convert the rest of head[31|64].S into C code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Calibrate delay and bogomips.Martin Schwidefsky2007-02-051-0/+1
| | | | | | | | | Preset the bogomips number to the cpu capacity value reported by store system information in SYSIB 1.2.2. This value is constant for a particular machine model and can be used to determine relative performance differences between machines. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] boot from NSS supportHongjie Yang2007-02-055-64/+275
| | | | | | | Add support to boot from a named saved segment (NSS). Signed-off-by: Hongjie Yang <hongjie@us.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] ETR support.Martin Schwidefsky2007-02-054-72/+1126
| | | | | | | | | | | | | This patch adds support for clock synchronization to an external time reference (ETR). The external time reference sends an oscillator signal and a synchronization signal every 2^20 microseconds to keep the TOD clocks of all connected servers in sync. For availability two ETR units can be connected to a machine. If the clock deviates for more than the sync-check tolerance all cpus get a machine check that indicates that the clock is out of sync. For the lovely details how to get the clock back in sync see the code below. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] noexec protectionGerald Schaefer2007-02-059-48/+111
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] kretprobe_trampoline_holder() in wrong section.Heiko Carstens2007-02-051-1/+1
| | | | | | | | | kretprobe_trampoline_holder() is in kprobes section but used to register a kprobe in arch_init_kprobes(). Hence register_kprobe() and therefore arch_init_kprobes() will fail. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fix kprobes breakpoint handling.Heiko Carstens2007-02-051-2/+9
| | | | | | | | In case of an illegal op the die notifier gets called with DIE_TRAP instead of DIE_BPT first. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fix FCP dump feature detection.Heiko Carstens2007-02-051-1/+5
| | | | | | | | | | FCP dump feature detection works only if the sclp command in head.S was succesful. Since the sclp command is skipped if diag260 works, we don't have any dump feature detection anymore. Bug was introduced with d57de5a36791cb1b7285649c62f183b0d3505f7d. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cpcmd with vmalloc addresses.Christian Borntraeger2007-02-051-7/+7
| | | | | | | | | | | | | | | | Change the bounce buffer logic of cpcmd. diag8 needs _real_ memory below 2GB. Therefore vmalloced data does not work. As the data might cross a page boundary, we cannot use virt_to_page either. The solution is to use virt_to_page only in the check for a bounce buffer. There was a redundant check for response==NULL. response < 2GB contains this check as well. I also removed the rlen==0 check, since rlen=0 and response!=NULL would be a caller bug and response==NULL is already checked. Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Remove pointless/unreliable kernel messages.Heiko Carstens2007-02-051-3/+0
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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