- 05 Sep, 2005 40 commits
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Heiko Carstens authored
On s390 the lock value used for spinlocks consists of the lower 32 bits of the PSW that holds the lock. If this address happens to be on a four gigabyte boundary the lock is left unlocked. This allows other cpus to grab the same lock and enter a lock protected code path concurrently. In theory this can happen if the vmalloc area for the code of a module crosses a 4 GB boundary. Signed-off-by:
Heiko Carstens <heiko.carstens@de.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>
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Heiko Carstens authored
Use TIF bit to tell if a process is running in 31 bit mode instead of checking the addressing mode bits of the PSW. Signed-off-by:
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Eric Rossman authored
crypto device driver update: - Suppress syslog messages for some return codes. - Fix incorrect bounds checking in /proc interface. - Remove hotplug calls. - Remove linux version checks. - Remove device workqueue on module unload. Signed-off-by:
Eric Rossman <edrossma@us.ibm.com> Signed-off-by:
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Martin Schwidefsky authored
There is a race in pfault_interrupt. That function gets called two times for each pfault notification. Once with a subcode of 0 to indicate that a real page is not available and once with a subcode of 0x80 to indicate that the page is present again. Since the two external interrupts can be delivered on two different cpus the order in which the two calls are made is unpredictable. It is possible that the subcode 0x80 interrupt is completed before the subcode 0x00 interrupt has done the wake_up() call. To avoid calling wake_up() on an already removed task structure proper task structure reference counting is needed. Increase the reference counter in the subcode 0x00 interrupt before setting pfault_wait to zero and return the reference after the wake_up call. Signed-off-by:
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Cornelia Huck authored
Common i/o layer changes: - Collect the irb at the correct subchannel when waiting for the clear interrupt during subchannel cleaning befor reIPL - don't stop at the first interrupt that comes in. - Change "extern __inline__" to "static inline". - Remove unneeded qdio includes. Signed-off-by:
Cornelia Huck <cohuck@de.ibm.com> Signed-off-by:
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Horst Hummel authored
Add support for diag 250 access to dasd devices for 64 bit kernels. In addition fix detach/attach for diag disks. The VM control block needs to get recreated by a call to mdsk_init_io. Signed-off-by:
Horst Hummel <horst.hummel@de.ibm.com> Signed-off-by:
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Horst Hummel authored
Reintroduce a read-only copy of the devmap features in the device struct. This is necessary to solve a deadlock on the dasd_devmap_lock which is acquired by dasd_get_features called from the dasd tasklet. The current implementation of devmap doesn't allow to call any devmap function from interrupt or softirq context. Signed-off-by:
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Michael Holzheu authored
debug feature changes/bug fixes: - Use get_clock() function instead of private inline assembly. - Use 'struct timeval' instead of 'struct timespec' for call to tod_to_timeval(). Now the microsecond part of the timestamp is correct again. - Fix a locking problem: when creating a snapshot of the current content of the debug areas, lock the entire debug_info object. Signed-off-by:
Michael Holzheu <holzheu@de.ibm.com> Signed-off-by:
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Martin Schwidefsky authored
The new machine check handler still has a few bugs. 1) The system entry time has to be stored in the machine check handler, 2) the machine check return psw may not be stored at the usual place because it might overwrite the return psw of the interrupted context, 3) the return address for the call to s390_handle_mcck in the i/o interrupt handler is not correct, 4) the system call cleanup has to take the different save area of the machine check handler into account, 5) the machine check handler may not call UPDATE_VTIME before CREATE_STACK_FRAME, and 6) the io leave path needs a critical section cleanup to make sure that the TIF_MCCK_PENDING bit is really checked before switching back to user space. Signed-off-by:
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Adrian Bunk authored
This file seems to be an accident. Signed-off-by:
Adrian Bunk <bunk@stusta.de> Signed-off-by:
Chris Zankel <chris@zankel.net> Signed-off-by:
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Adrian Bunk authored
"extern inline" doesn't make sense. Signed-off-by:
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Jeff Dike authored
We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled. This fixes that. Signed-off-by:
Jeff Dike <jdike@addtoit.com> Signed-off-by:
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Bodo Stroesser authored
cleanup and fix the check for advanced sysemu (PTRACE_SYSEMU_SINGLESTEP option) Signed-off-by:
Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by:
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Bodo Stroesser authored
Add new cmdline setups: - noprocmm - noptracefaultinfo In case of testing, they can be used to switch off usage of /proc/mm and PTRACE_FAULTINFO independently. Signed-off-by:
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Bodo Stroesser authored
Change syscall-stub's data to include a "expected retval". Stub now checks syscalls retval and aborts execution of syscall list, if retval != expected retval. run_syscall_stub prints the data of the failed syscall, using the data pointer and retval written by the stub to the beginning of the stack. one_syscall_stub is removed, to simplify code, because only some instructions are saved by one_syscall_stub, no host-syscall. Using the stub with additional data (modify_ldt via stub) is prepared also. Signed-off-by:
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Bodo Stroesser authored
This change enables SKAS0/SKAS3 to work with all combinations of /proc/mm and PTRACE_FAULTINFO being available or not. Also it changes the initialization of proc_mm and ptrace_faultinfo slightly, to ease forcing SKAS0 on a patched host. Forcing UML to run without /proc/mm or PTRACE_FAULTINFO by cmdline parameter can be implemented with a setup resetting the related variable. Signed-off-by:
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Gennady Sharapov authored
The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from process.c file under os-Linux dir and join process.c and process_kern.c files. Signed-off-by:
Gennady Sharapov <gennady.v.sharapov@intel.com> Signed-off-by:
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Jeff Dike authored
This adds AIO support to the ubd driver. The driver breaks a struct request into IO requests to the host, based on the hardware segments in the request and on any COW blocks covered by the request. The ubd IO thread is gone, since there is now an equivalent thread in the AIO module. There is provision for multiple outstanding requests now. Requests aren't retired until all pieces of it have been completed. The AIO requests have a shared count, which is decremented as IO operations come in until it reaches 0. This can be possibly moved to the request struct - haven't looked at this yet. Signed-off-by:
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Jeff Dike authored
This patch makes UML use host AIO support when it (and /usr/include/linux/aio_abi.h) are present. This is only the support, with no consumers - a consumer is coming in the next patch. Signed-off-by:
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Al Viro authored
Added missing include list to uml AFLAGS Killed magic for stubs. [So] - it was needed only because of messed AFLAGS Switched segv_stubs.c to kernel CFLAGS sans profile, instead of user ones Killed STUBS_CFLAGS - it's not needed and the only remaining use had been gratitious - it only polluted CFLAGS Signed-off-by:
Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by:
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Jeff Dike authored
This merges two sets of files which had no business being split apart in the first place. Signed-off-by:
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Jeff Dike authored
There is a lot of code which is duplicated between the 2 and 3 level implementation, with the only difference that the 3-level implementation is a bit more generalized (instead of accessing directly pte_t.pte, it uses the appropriate access macros). So this code is joined together. As obvious, a "core code nice cleanup" is not a "stability-friendly patch" so usual care applies. Signed-off-by:
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
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Jeff Dike authored
This adds VM op batching to skas0. Rather than having a context switch to and from the userspace stub for each address space change, we write a number of operations to the stub data page and invoke a different stub which loops over them and executes them all in one go. The operations are stored as [ system call number, arg1, arg2, ... ] tuples. The set is terminated by a system call number of 0. Single operations, i.e. page faults, are handled in the old way, since that is slightly more efficient. For a kernel build, a minority (~1/4) of the operations are part of a set. These sets averaged ~100 in length, so for this quarter, the context switching overhead is greatly reduced. Signed-off-by:
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Jeff Dike authored
Al Viro <viro@parcelfarce.linux.theplanet.co.uk> spotted a bunch of duplicated exports - this removes them. Signed-off-by:
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Jeff Dike authored
Noticed by Al Viro <viro@parcelfarce.linux.theplanet.co.uk> - SMP on x86_64 is fundamentally broken due to UML's reuse of the host arch's percpu stuff. This is OK on x86, but the x86_64 pda stuff just won't work for UML. Signed-off-by:
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Al Viro authored
Remove an unneeded reference to libc. Signed-off-by:
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Al Viro authored
Build cleanups Signed-off-by:
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Jeff Dike authored
This cleans up the error path in ubd_open, causing it now to call ubd_close appropriately when something fails. Signed-off-by:
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Al Viro authored
Fix a macro typo which could break if the macro is passed arguments with side-effects. Signed-off-by:
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Al Viro authored
The copy_user stuff in the signal frame code was broke. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
Avoid chomping low bits of address for functions doing it by themselves, fix whitespace, add a correctness checking. I did this for remap-file-pages protection support, it was useful on its own too. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
Normally, activate_mm() is called from exec(), and thus it used to be a no-op because we use a completely new "MM context" on the host (for instance, a new process), and so we didn't need to flush any "TLB entries" (which for us are the set of memory mappings for the host process from the virtual "RAM" file). Kernel threads, instead, are usually handled in a different way. So, when for AIO we call use_mm(), things used to break and so Benjamin implemented activate_mm(). However, that is only needed for AIO, and could slow down exec() inside UML, so be smart: detect being called for AIO (via PF_BORROWED_MM) and do the full flush only in that situation. Comment also the caller so that people won't go breaking UML without noticing. I also rely on the caller's locks for testing current->flags. Signed-off-by:
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Bodo Stroesser authored
If a SIGWINCH comes in, while winch_thread() isn't waiting in wait(), winch_thread could miss signals. It isn't very probable, that anyone will see this causing trouble, as it would need a very special timing, that a missed SIGWINCH results in a wrong window size. So, this is a minor problem. But why not fix, as it can be done so easy? Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
Apparently, GDB gets confused when we do an execvp() on ourselves. Since it's simply done to allocate further space for command line arguments (which we'll use to allow gathering the startup command line for guest processes through the host), allow the user to disable that to get a debuggable UML binary. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
As a follow-up to "UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage" (i.e. uml-support-* in current mm). Avoid unconditionally jumping to work_pending and code copying, just reuse the already existing resume_userspace path. One interesting note, from Charles P. Wright, suggested that the API is improvable with no downsides for UML (except that it will have to support yet another host API, since dropping support for the current API, for UML, is not reasonable from users' point of view). Signed-off-by:
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Bodo Stroesser authored
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> This is simply an adjustment for "Ptrace - i386: fix Syscall Audit interaction with singlestep" to work on top of SYSEMU patches, too. On this patch, I have some doubts: I wonder why we need to alter that way ptrace_disable(). I left the patch this way because it has been extensively tested, but I don't understand the reason. The current PTRACE_DETACH handling simply clears child->ptrace; actually this is not enough because entry.S just looks at the thread_flags; actually, do_syscall_trace checks current->ptrace but I don't think depending on that is good, at least for performance, so I think the clearing is done elsewhere. For instance, on PTRACE_CONT it's done, but doing PTRACE_DETACH without PTRACE_CONT is possible (and happens when gdb crashes and one kills it manually). Signed-off-by: -
Bodo Stroesser authored
This patch implements the new ptrace option PTRACE_SYSEMU_SINGLESTEP, which can be used by UML to singlestep a process: it will receive SINGLESTEP interceptions for normal instructions and syscalls, but syscall execution will be skipped just like with PTRACE_SYSEMU. Signed-off-by:
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Bodo Stroesser authored
With this patch, we change the way we handle switching from PTRACE_SYSEMU to PTRACE_{SINGLESTEP,SYSCALL}, to free TIF_SYSCALL_EMU from double use as a preparation for PTRACE_SYSEMU_SINGLESTEP extension, without changing the behavior of the host kernel. Signed-off-by: -
Laurent Vivier authored
Jeff Dike <jdike@addtoit.com>, Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>, Bodo Stroesser <bstroesser@fujitsu-siemens.com> Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL except that the kernel does not execute the requested syscall; this is useful to improve performance for virtual environments, like UML, which want to run the syscall on their own. In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry and on exit, and each time you also have two context switches; with SYSEMU you avoid the 2nd stop and so save two context switches per syscall. Also, some architectures don't have support in the host for changing the syscall number via ptrace(), which is currently needed to skip syscall execution (UML turns any syscall into getpid() to avoid it being executed on the host). Fixing that is hard, while SYSEMU is easier to implement. * This version of the patch includes some suggestions of Jeff Dike to avoid adding any instructions to the syscall fast path, plus some other little changes, by myself, to make it work even when the syscall is executed with SYSENTER (but I'm unsure about them). It has been widely tested for quite a lot of time. * Various fixed were included to handle the various switches between various states, i.e. when for instance a syscall entry is traced with one of PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit. Basically, this is done by remembering which one of them was used even after the call to ptrace_notify(). * We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP to make do_syscall_trace() notice that the current syscall was started with SYSEMU on entry, so that no notification ought to be done in the exit path; this is a bit of a hack, so this problem is solved in another way in next patches. * Also, the effects of the patch: "Ptrace - i386: fix Syscall Audit interaction with singlestep" are cancelled; they are restored back in the last patch of this series. Detailed descriptions of the patches doing this kind of processing follow (but I've already summed everything up). * Fix behaviour when changing interception kind #1. In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag only after doing the debugger notification; but the debugger might have changed the status of this flag because he continued execution with PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag status before calling ptrace_notify(). * Fix behaviour when changing interception kind #2: avoid intercepting syscall on return when using SYSCALL again. A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL crashes. The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch inhibits the syscall-handler to be called, but does not prevent do_syscall_trace() to be called after this for syscall completion interception. The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since the flag is unused in the depicted situation. * Fix behaviour when changing interception kind #3: avoid intercepting syscall on return when using SINGLESTEP. When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had problems with singlestepping on UML in SKAS with SYSEMU. It looped receiving SIGTRAPs without moving forward. EIP of the traced process was the same for all SIGTRAPs. What's missing is to handle switching from PTRACE_SYSCALL_EMU to PTRACE_SINGLESTEP in a way very similar to what is done for the change from PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE. I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is notified and then wake ups the process; the syscall is executed (or skipped, when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and do_syscall_trace() is called again. Since we are on the return path of a SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL), we must still avoid notifying the parent of the syscall exit. Now, this behaviour is extended even to resuming with PTRACE_SINGLESTEP. Signed-off-by: -
Bodo Stroesser authored
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Avoid giving two traps for singlestep instead of one, when syscall auditing is enabled. In fact no singlestep trap is sent on syscall entry, only on syscall exit, as can be seen in entry.S: # Note that in this mask _TIF_SINGLESTEP is not tested !!! <<<<<<<<<<<<<< testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),TI_flags(%ebp) jnz syscall_trace_entry ... syscall_trace_entry: ... call do_syscall_trace But auditing a SINGLESTEP'ed process causes do_syscall_trace to be called, so the tracer will get one more trap on the syscall entry path, which it shouldn't. Signed-off-by:
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