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* [S390] noexec protectionGerald Schaefer2007-02-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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] Add __must_check to uaccess functions.Heiko Carstens2006-12-041-9/+9
| | | | | | | Follow other architectures and add __must_check to uaccess functions. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Inline assembly cleanup.Martin Schwidefsky2006-09-281-12/+1
| | | | | | | | | | | | Major cleanup of all s390 inline assemblies. They now have a common coding style. Quite a few have been shortened, mainly by using register asm variables. Use of the EX_TABLE macro helps as well. The atomic ops, bit ops and locking inlines new use the Q-constraint if a newer gcc is used. That results in slightly better code. Thanks to Christian Borntraeger for proof reading the changes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Use alternative user-copy operations for new hardware.Gerald Schaefer2006-09-201-0/+1
| | | | | | | | This introduces new user-copy operations which are optimized for copying more than 256 Bytes on new hardware. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Make user-copy operations run-time configurable.Gerald Schaefer2006-09-201-115/+56
| | | | | | | | Introduces a struct uaccess_ops which allows setting user-copy operations at run-time. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [PATCH] s390 __get_user() bogus warnings removalAl Viro2006-02-081-4/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] s390 misc __user annotationsAl Viro2006-02-081-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] s390: uaccess warningsMartin Schwidefsky2006-01-061-6/+8
| | | | | | | | | Convert __access_ok to an inline C function and change __get_user primitive to avoid uaccess compiler warnings. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390: const pointer uaccessMartin Schwidefsky2005-11-071-6/+22
| | | | | | | | | Using __typeof__(*ptr) on a pointer to const makes the __x variable in __get_user const as well. The latest gcc will refuse to write to it. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove verify_area(): remove verify_area() from various uaccess.h ↵Jesper Juhl2005-09-071-7/+0
| | | | | | | | | | | headers Remove the deprecated (and unused) verify_area() from various uaccess.h headers. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390 __CHECKER__ ifdefsAl Viro2005-08-231-19/+2
| | | | | | | remove the bogus games with explicit ifdefs on __CHECKER__ Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+436
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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