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* s390/compat: correct uc_sigmask of the compat signal frameMartin Schwidefsky2015-10-131-4/+26
| | | | | | | | | | | | | | | | | | | | | commit 8d4bd0ed0439dfc780aab801a085961925ed6838 upstream. The uc_sigmask in the ucontext structure is an array of words to keep the 64 signal bits (or 1024 if you ask glibc but the kernel sigset_t only has 64 bits). For 64 bit the sigset_t contains a single 8 byte word, but for 31 bit there are two 4 byte words. The compat signal handler code uses a simple copy of the 64 bit sigset_t to the 31 bit compat_sigset_t. As s390 is a big-endian architecture this is incorrect, the two words in the 31 bit sigset_t array need to be swapped. Reported-by: Stefan Liebler <stli@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: - Introduce local compat_sigset_t in setup_frame32() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* s390/signal: set correct address space controlMartin Schwidefsky2012-12-061-2/+12
| | | | | | | | | | | | | | | | | | | | | | | commit fa968ee215c0ca91e4a9c3a69ac2405aae6e5d2f upstream. If user space is running in primary mode it can switch to secondary or access register mode, this is used e.g. in the clock_gettime code of the vdso. If a signal is delivered to the user space process while it has been running in access register mode the signal handler is executed in access register mode as well which will result in a crash most of the time. Set the address space control bits in the PSW to the default for the execution of the signal handler and make sure that the previous address space control is restored on signal return. Take care that user space can not switch to the kernel address space by modifying the registers in the signal frame. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: - Adjust filename - The RI bit is not included in PSW_MASK_USER] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* [S390] sparse: fix sparse warnings with __user pointersMartin Schwidefsky2011-10-301-11/+12
| | | | | | Use __force to quiet sparse warnings about user address space. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] sparse: fix access past end of array warningsMartin Schwidefsky2011-10-301-24/+4
| | | | | | | | Remove unnecessary code to avoid false positives from sparse, e.g. arch/s390/kernel/compat_signal.c:221:61: warning: invalid access past the end of 'set32' (8 8) Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] allow all addressing modesMartin Schwidefsky2011-10-301-4/+8
| | | | | | | | | | | | | | | | | The user space program can change its addressing mode between the 24-bit, 31-bit and the 64-bit mode if the kernel is 64 bit. Currently the kernel always forces the standard amode on signal delivery and signal return and on ptrace: 64-bit for a 64-bit process, 31-bit for a compat process and 31-bit kernels. Change the signal and ptrace code to allow the full range of addressing modes. Signal handlers are run in the standard addressing mode for the process. One caveat is that even an 31-bit compat process can switch to the 64-bit mode. The next signal will switch back into the 31-bit mode and there is no room in the 31-bit compat signal frame to store the information that the program came from the 64-bit mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup psw related bits and piecesMartin Schwidefsky2011-10-301-5/+5
| | | | | | | | | | Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] add TIF_SYSCALL thread flagMartin Schwidefsky2011-10-301-1/+1
| | | | | | | | | | Add an explicit TIF_SYSCALL bit that indicates if a task is inside a system call. The svc_code in the pt_regs structure is now only valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC can be replaced with TIF_SYSCALL. Overall do_signal is a bit more readable and it saves a few lines of code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] signal race with restarting system callsMartin Schwidefsky2011-10-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a ERESTARTNOHAND/ERESTARTSYS/ERESTARTNOINTR restarting system call do_signal will prepare the restart of the system call with a rewind of the PSW before calling get_signal_to_deliver (where the debugger might take control). For A ERESTART_RESTARTBLOCK restarting system call do_signal will set -EINTR as return code. There are two issues with this approach: 1) strace never sees ERESTARTNOHAND, ERESTARTSYS, ERESTARTNOINTR or ERESTART_RESTARTBLOCK as the rewinding already took place or the return code has been changed to -EINTR 2) if get_signal_to_deliver does not return with a signal to deliver the restart via the repeat of the svc instruction is left in place. This opens a race if another signal is made pending before the system call instruction can be reexecuted. The original system call will be restarted even if the second signal would have ended the system call with -EINTR. These two issues can be solved by dropping the early rewind of the system call before get_signal_to_deliver has been called and by using the TIF_RESTART_SVC magic to do the restart if no signal has to be delivered. The only situation where the system call restart via the repeat of the svc instruction is appropriate is when a SA_RESTART signal is delivered to user space. Unfortunately this breaks inferior calls by the debugger again. The system call number and the length of the system call instruction is lost over the inferior call and user space will see ERESTARTNOHAND/ ERESTARTSYS/ERESTARTNOINTR/ERESTART_RESTARTBLOCK. To correct this a new ptrace interface is added to save/restore the system call number and system call instruction length. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] signal: convert to use set_current_blocked()Heiko Carstens2011-08-031-31/+12
| | | | | | Convert to use set_current_blocked() like x86. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] 64-bit register support for 31-bit processesHeiko Carstens2009-10-061-1/+34
| | | | | | | | From: Heiko Carstens <heiko.carstens@de.ibm.com> From: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] fix system call parameter functions.Martin Schwidefsky2008-11-271-1/+1
| | | | | | | | | | | | | | | | | | syscall_get_nr() currently returns a valid result only if the call chain of the traced process includes do_syscall_trace_enter(). But collect_syscall() can be called for any sleeping task, the result of syscall_get_nr() in general is completely bogus. To make syscall_get_nr() work for any sleeping task the traps field in pt_regs is replace with svcnr - the system call number the process is executing. If svcnr == 0 the process is not on a system call path. The syscall_get_arguments and syscall_set_arguments use regs->gprs[2] for the first system call parameter. This is incorrect since gprs[2] may have been overwritten with the system call number if the call chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fix a lot of sparse warnings.Heiko Carstens2008-04-171-0/+1
| | | | | | | | | | | Most noteable part of this commit is the new local header file entry.h which contains all the function declarations of functions that get only called from asm code or are arch internal. That way we can avoid extern declarations in C files. This is more or less the same that was done for sparc64. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Protect against sigaltstack wraparound.Heiko Carstens2008-04-171-0/+10
| | | | | | | | This is just a port of 83bd01024b1fdfc41d9b758e5669e80fca72df66 "x86: protect against sigaltstack wraparound". Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* header cleaning: don't include smp_lock.h when not usedRandy Dunlap2007-05-081-1/+0
| | | | | | | | | | | | Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [S390] System call cleanup.Martin Schwidefsky2007-04-271-6/+8
| | | | | | | | | | | 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] noexec protectionGerald Schaefer2007-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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] Get rid of a lot of sparse warnings.Heiko Carstens2007-02-051-3/+3
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] uaccess error handling.Heiko Carstens2006-10-271-6/+6
| | | | | | | | Consider return values for all user space access function and return -EFAULT on error. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] s390: alternate signal stack handling bugLaurent Meyer2006-04-281-1/+1
| | | | | | | | | | | | | | If a signal handler has been established with the SA_ONSTACK option but no alternate stack is provided with sigaltstack(), the kernel still tries to install the alternate stack. Also when setting an alternate stack with sigalstack() and the SS_DISABLE flag, the kernel tries to install the alternate stack on signal delivery. Use the correct conditions sas_ss_flags() to check if the alternate stack has to be used. Signed-off-by: Laurent Meyer <meyerlau@fr.ibm.com> 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] Fix s390 build failure.Dave Jones2006-02-101-3/+0
| | | | | | | | arch/s390/kernel/compat_signal.c:199: error: conflicting types for 'do_sigaction' include/linux/sched.h:1115: error: previous declaration of 'do_sigaction' was here Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390: Add support for new syscalls/TIF_RESTORE_SIGMASKHeiko Carstens2006-02-011-79/+23
| | | | | | | | | Add support for the new *at, pselect6 and ppoll system calls. This includes adding required support for TIF_RESTORE_SIGMASK. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390: rt_sigreturn fixCedric Le Goater2006-01-061-2/+0
| | | | | | | | | Check return code of do_sigaltstack and force a SIGSEGV if it is -EFAULT. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390 signal annotationsAl Viro2005-09-291-3/+3
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] convert signal handling of NODEFER to act like other Unix boxes.Steven Rostedt2005-08-291-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It has been reported that the way Linux handles NODEFER for signals is not consistent with the way other Unix boxes handle it. I've written a program to test the behavior of how this flag affects signals and had several reports from people who ran this on various Unix boxes, confirming that Linux seems to be unique on the way this is handled. The way NODEFER affects signals on other Unix boxes is as follows: 1) If NODEFER is set, other signals in sa_mask are still blocked. 2) If NODEFER is set and the signal is in sa_mask, then the signal is still blocked. (Note: this is the behavior of all tested but Linux _and_ NetBSD 2.0 *). The way NODEFER affects signals on Linux: 1) If NODEFER is set, other signals are _not_ blocked regardless of sa_mask (Even NetBSD doesn't do this). 2) If NODEFER is set and the signal is in sa_mask, then the signal being handled is not blocked. The patch converts signal handling in all current Linux architectures to the way most Unix boxes work. Unix boxes that were tested: DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU 3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX. * NetBSD was the only other Unix to behave like Linux on point #2. The main concern was brought up by point #1 which even NetBSD isn't like Linux. So with this patch, we leave NetBSD as the lonely one that behaves differently here with #2. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+648
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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