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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] Get rid of a lot of sparse warnings.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-05-01[PATCH] drop task argument of audit_syscall_{entry,exit}Al Viro
... it's always current, and that's a good thing - allows simpler locking. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-01-12[PATCH] s390: task_pt_regs()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] use ptrace_get_task_struct in various placesChristoph Hellwig
The ptrace_get_task_struct() helper that I added as part of the ptrace consolidation is useful in variety of places that currently opencode it. Switch them to the common helpers. Add a ptrace_traceme() helper that needs to be explicitly called, and simplify the ptrace_get_task_struct() interface. We don't need the request argument now, and we return the task_struct directly, using ERR_PTR() for error returns. It's a bit more code in the callers, but we have two sane routines that do one thing well now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] s390: cleanup KconfigMartin Schwidefsky
Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X, ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by S390, 64BIT and COMPAT. 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>
2005-06-04[PATCH] s390: uml ptrace fixesBodo Stroesser
To make UML build and run on s390, I needed to do these two little changes: 1) UML includes some of the subarch's (s390) headers. I had to change one of them with the following one-liner, to make this compile. AFAICS, this change doesn't break compilation of s390 itself. 2) UML needs to intercept syscalls via ptrace to invalidate the syscall, read syscall's parameters and write the result with the result of UML's syscall processing. Also, UML needs to make sure, that the host does no syscall restart processing. On i386 for example, this can be done by writing -1 to orig_eax on the 2nd syscall interception (orig_eax is the syscall number, which after the interception is used as a "interrupt was a syscall" flag only. Unfortunately, s390 holds syscall number and syscall result in gpr2 and its "interrupt was a syscall" flag (trap) is unreachable via ptrace. So I changed the host to set trap to -1, if the syscall number is changed to an invalid value on the first syscall interception. 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>
2005-06-04[PATCH] s390: ptrace peek and pokeMartin Schwidefsky
The special cases of peek and poke on acrs[15] and the fpc register are not handled correctly. A poke on acrs[15] will clobber the 4 bytes after the access registers in the thread_info structure. That happens to be the kernel stack pointer. A poke on the fpc with an invalid value is not caught by the validity check. On the next context switch the broken fpc value will cause a program check in the kernel. Improving the checks in peek and poke fixes this. 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>
2005-05-03Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.gitDavid Woodhouse
2005-05-01[PATCH] convert that currently tests _NSIG directly to use valid_signal()Jesper Juhl
Convert most of the current code that uses _NSIG directly to instead use valid_signal(). This avoids gcc -W warnings and off-by-one errors. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-29[AUDIT] Don't allow ptrace to fool auditing, log arch of audited syscalls.
We were calling ptrace_notify() after auditing the syscall and arguments, but the debugger could have _changed_ them before the syscall was actually invoked. Reorder the calls to fix that. While we're touching ever call to audit_syscall_entry(), we also make it take an extra argument: the architecture of the syscall which was made, because some architectures allow more than one type of syscall. Also add an explicit success/failure flag to audit_syscall_exit(), for the benefit of architectures which return that in a condition register rather than only returning a single register. Change type of syscall return value to 'long' not 'int'. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
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!