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2007-03-26[S390] kprobes: Align probe address.David Wilder
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>
2007-03-19[S390] Wire up sys_utimes.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-03-19[S390] reboot from and dump to SCSI under z/VM fails.Michael Holzheu
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>
2007-03-19[S390] Wire up compat_sys_epoll_pwait.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-03-19[S390] strlcpy is smart enoughJean Delvare
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>
2007-03-19[S390] memory detection: fix off by one bug.Heiko Carstens
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>
2007-03-14[PATCH] appldata build fixAl Viro
PGALLOC_DMA is defined only if we have CONFIG_ZONE_DMA Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[S390] Fixed handling of access register mode faults.Gerald Schaefer
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>
2007-03-05[S390] nss: disable kexec.Heiko Carstens
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>
2007-03-05[S390] reipl: move dump_prefix_page out of text section.Heiko Carstens
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>
2007-03-05[S390] smp: disable preemption in smp_call_function/smp_call_function_onHeiko Carstens
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>
2007-03-05[S390] kprobes breaks BUG_ONMartin Schwidefsky
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>
2007-02-21[S390] Replace $(ARCH) macros in MakefileMichael Holzheu
Since $(ARCH) is always "s390" we can replace it with "s390". Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-21[S390] nss: Free unused memory in kernel image.Heiko Carstens
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>
2007-02-21[S390] bss section clearing.Heiko Carstens
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>
2007-02-21[S390] Remove BUG() statementMichael Holzheu
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>
2007-02-21[S390] New header file ipl.hMichael Holzheu
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>
2007-02-21[S390] New get_cpu_id() inline assemblyMichael Holzheu
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>
2007-02-21[S390] etr: Add barrier() to etr_sync_cpu_start().Heiko Carstens
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>
2007-02-21[S390] Optional ZONE_DMA for s390.Heiko Carstens
Disable ZONE_DMA on 31-bit. All memory is addressable by all devices and we do not need any special memory pool. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-21[S390] smp_call_function cleanupJan Glauber
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>
2007-02-21[S390] prevent softirqs if delay is called disabledMartin Schwidefsky
The new delay implementation uses the clock comparator and an external interrupt even if it is called disabled for interrupts. To do this all external interrupt source except clock comparator are switched of before enabling external interrupts. The external interrupt at the end of the delay period may not execute softirqs or we can end up in a dead-lock. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-21[S390] update default configurationMartin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-16[PATCH] clocksource: fixup is_continous changes on S390Thomas Gleixner
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>
2007-02-14[PATCH] sysctl: remove insert_at_head from register_sysctlEric W. Biederman
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>
2007-02-14[PATCH] sysctl: s390: remove unnecessary use of insert_at_headEric W. Biederman
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>
2007-02-14[PATCH] sysctl: s390: move sysctl definitions to sysctl.hEric W. Biederman
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>
2007-02-12Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds
* '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.
2007-02-12[PATCH] mark struct file_operations const 2Arjan van de Ven
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>
2007-02-12[PATCH] Dynamic kernel command-line: s390Alon Bar-Lev
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>
2007-02-12[S390] smp_call_function/smp_call_function_on locking.Heiko Carstens
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>
2007-02-11[PATCH] Switch s390 to NO_IOMEMAl Viro
Martin Schwidefsky wrote: "s390 does not even need (in|out)b(_p|). I wondered what else from io.h do we not need. The answer is: almost nothing. With the devres patch from Al and the dma-mapping patch from Heiko we can get rid of iomem and all associated definitions." So we'll just need to replace NO_IOPORT with NO_IOMEM in Kconfig and kill arch/s390/mm/ioremap.c. BTW, there's an annoying bit of junk in there - IO_SPACE_LIMIT. We only need it for /proc/ioports, which AFAICS shouldn't even be there on s390 (or uml). OTOH, removing that thing would mean a user-visible change - we go from "empty file in /proc" to "no such file in /proc"... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] sort the devres mess outAl Viro
* Split the implementation-agnostic stuff in separate files. * Make sure that targets using non-default request_irq() pull kernel/irq/devres.o * Introduce new symbols (HAS_IOPORT and HAS_IOMEM) defaulting to positive; allow architectures to turn them off (we needed these symbols anyway for dependencies of quite a few drivers). * protect the ioport-related parts of lib/devres.o with CONFIG_HAS_IOPORT. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Consolidate bust_spinlocks()Kirill Korotaev
Part of long forgotten patch http://groups.google.com/group/fa.linux.kernel/msg/e98e941ce1cf29f6?dmode=source Since then, m32r grabbed two copies. Leave s390 copy because of important absence of CONFIG_VT, but remove references to non-existent timerlist_lock. ia64 also loses timerlist_lock. Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@muc.de> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Common compat_sys_sysinfoKyle McMartin
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>
2007-02-11[PATCH] disable init/initramfs.c: architecturesJean-Paul Saman
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>
2007-02-11[PATCH] optional ZONE_DMA: introduce CONFIG_ZONE_DMAChristoph Lameter
This patch simply defines CONFIG_ZONE_DMA for all arches. We later do special things with CONFIG_ZONE_DMA after the VM and an arch are prepared to work without ZONE_DMA. CONFIG_ZONE_DMA can be defined in two ways depending on how an architecture handles ISA DMA. First if CONFIG_GENERIC_ISA_DMA is set by the arch then we know that the arch needs ZONE_DMA because ISA DMA devices are supported. We can catch this in mm/Kconfig and do not need to modify arch code. Second, arches may use ZONE_DMA in an unknown way. We set CONFIG_ZONE_DMA for all arches that do not set CONFIG_GENERIC_ISA_DMA in order to insure backwards compatibility. The arches may later undefine ZONE_DMA if their arch code has been verified to not depend on ZONE_DMA. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <willy@debian.org> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-08[S390]: Add AF_IUCV socket supportJennifer Hunt
From: Jennifer Hunt <jenhunt@us.ibm.com> This patch adds AF_IUCV socket support. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08[S390]: Rewrite of the IUCV base code, part 2Martin Schwidefsky
Add rewritten IUCV base code to net/iucv. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08[S390]: Rewrite of the IUCV base code, part 1Martin Schwidefsky
Remove the old IUCV code from drivers/s390/net Remove approprirate IUCV entries from drivers/s390/net/Makefile, drivers/s390/net/Kconfig and arch/s390/defconfig Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-05[S390] Avoid excessive inlining.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05[S390] Mark kernel text section read-only.Heiko Carstens
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>
2007-02-05[S390] Convert memory detection into C code.Heiko Carstens
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>
2007-02-05[S390] Calibrate delay and bogomips.Martin Schwidefsky
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>
2007-02-05[S390] Hypervisor filesystem (s390_hypfs) for z/VMMichael Holzheu
This is an extension of the already existing hypfs for LPAR (DIAG 204). Data returned by DIAG 2fc is exported using the s390_hypfs when Linux is running under z/VM. Information about cpus and memory is provided. Data is put into different virtual files which can be accessed from user space. All values are represented as ASCII strings Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05[S390] boot from NSS supportHongjie Yang
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>
2007-02-05[S390] Support for s390 Pseudo Random Number GeneratorJan Glauber
Starting with the z9 the CPU Cryptographic Assist Facility comes with an integrated Pseudo Random Number Generator. The generator creates random numbers by an algorithm similar to the ANSI X9.17 standard. The pseudo-random numbers can be accessed via a character device driver node called /dev/prandom. Similar to /dev/urandom any amount of bytes can be read from the device without blocking. Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05[S390] ETR support.Martin Schwidefsky
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>
2007-02-05[S390] noexec protectionGerald Schaefer
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>
2007-02-05[S390] move crypto options and some cleanup.Jan Glauber
This patch moves the config options for the s390 crypto instructions to the standard "Hardware crypto devices" menu. In addition some cleanup has been done: use a flag for supported keylengths, add a warning about machien limitation, return ENOTSUPP in case the hardware has no support, remove superfluous printks and update email addresses. Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>