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* uml: shrink kernel stacksJeff Dike2007-05-11
| | | | | | | | | | Make kernel stacks be 1 page on i386 and 2 pages on x86_64. These match the host values. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: iRQ stacksJeff Dike2007-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a separate IRQ stack. This differs from i386 in having the entire interrupt run on a separate stack rather than starting on the normal kernel stack and switching over once some preparation has been done. The underlying mechanism, is of course, sigaltstack. Another difference is that interrupts that happen in userspace are handled on the normal kernel stack. These cause a wait wakeup instead of a signal delivery so there is no point in trying to switch stacks for these. There's no other stuff on the stack, so there is no extra stack consumption. This quirk makes it possible to have the entire interrupt run on a separate stack - process preemption (and calls to schedule()) happens on a normal kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought. The IRQ stack for CPU 0 is declared in the same way as the initial kernel stack. IRQ stacks for other CPUs will be allocated dynamically. An extra field was added to the thread_info structure. When the active thread_info is copied to the IRQ stack, the real_thread field points back to the original stack. This makes it easy to tell where to copy the thread_info struct back to when the interrupt is finished. It also serves as a marker of a nested interrupt. It is NULL for the first interrupt on the stack, and non-NULL for any nested interrupts. Care is taken to behave correctly if a second interrupt comes in when the thread_info structure is being set up or taken down. I could just disable interrupts here, but I don't feel like giving up any of the performance gained by not flipping signals on and off. If an interrupt comes in during these critical periods, the handler can't run because it has no idea what shape the stack is in. So, it sets a bit for its signal in a global mask and returns. The outer handler will deal with this signal itself. Atomicity is had with xchg. A nested interrupt that needs to bail out will xchg its signal mask into pending_mask and repeat in case yet another interrupt hit at the same time, until the mask stabilizes. The outermost interrupt will set up the thread_info and xchg a zero into pending_mask when it is done. At this point, nested interrupts will look at ->real_thread and see that no setup needs to be done. They can just continue normally. Similar care needs to be taken when exiting the outer handler. If another interrupt comes in while it is copying the thread_info, it will drop a bit into pending_mask. The outer handler will check this and if it is non-zero, will loop, set up the stack again, and handle the interrupt. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tidy IRQ codeJeff Dike2007-05-11
| | | | | | | | | | | Some tidying of the irq code before introducing irq stacks. Mostly style fixes, but the timer handler calls the timer code directly rather than going through the generic sig_handler_common_skas. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: use UM_THREAD_SIZE in userspace codeJeff Dike2007-05-11
| | | | | | | | | | | Now that we have UM_THREAD_SIZE, we can replace the calculations in user-space code (an earlier patch took care of the kernel side of the house). Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove task_protectionsJeff Dike2007-05-11
| | | | | | | | | | | | | | Replaced task_protections with stack_protections since they do the same thing, and task_protections was misnamed anyway. This needs THREAD_SIZE, so that's imported via common-offsets.h Also tidied up the code in the vicinity. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds2007-05-09
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits) sound: convert "sound" subdirectory to UTF-8 MAINTAINERS: Add cxacru website/mailing list include files: convert "include" subdirectory to UTF-8 general: convert "kernel" subdirectory to UTF-8 documentation: convert the Documentation directory to UTF-8 Convert the toplevel files CREDITS and MAINTAINERS to UTF-8. remove broken URLs from net drivers' output Magic number prefix consistency change to Documentation/magic-number.txt trivial: s/i_sem /i_mutex/ fix file specification in comments drivers/base/platform.c: fix small typo in doc misc doc and kconfig typos Remove obsolete fat_cvf help text Fix occurrences of "the the " Fix minor typoes in kernel/module.c Kconfig: Remove reference to external mqueue library Kconfig: A couple of grammatical fixes in arch/i386/Kconfig Correct comments in genrtc.c to refer to correct /proc file. Fix more "deprecated" spellos. Fix "deprecated" typoes. ... Fix trivial comment conflict in kernel/relay.c.
| * fix file specification in commentsUwe Kleine-König2007-05-09
| | | | | | | | | | | | | | Many files include the filename at the beginning, serveral used a wrong one. Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* | uml: turn build warnings into commentsMiklos Szeredi2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These haven't been fixed for ages. Just make comments out of them. arch/um/kernel/skas/process.c:181:2: warning: #warning Need to look up +userspace_pid by cpu arch/um/kernel/skas/process.c:187:2: warning: #warning Need to look up +userspace_pid by cpu arch/um/kernel/skas/process.c:194:2: warning: #warning need to loop over +userspace_pids in kill_off_processes_skas Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | uml: mark a tt-only functionJeff Dike2007-05-09
| | | | | | | | | | | | | | | | | | Mark another function as tt-mode only. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | uml: turn on SCSI supportPeter Zijlstra2007-05-09
|/ | | | | | | | | | | Enable (i)SCSI on UML, dunno why SCSI was deemed broken, it works like a charm. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: pcap devices should get MACs from command lineJeff Dike2007-05-08
| | | | | | | | | | | Allow a pcap device to be assigned a MAC on the command line. They don't really need one, but it is handy to be able to do when your distro assigns a new ethernet device whenever it sees a new MAC. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: network and pcap cleanupJeff Dike2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some network device cleanup. When setup_etheraddr found a globally valid MAC being assigned to an interface, it went ahead and used it rather than assigning a random MAC like the other cases do. This isn't really an error like the others, but it seems consistent to make it behave the same. We were getting some duplicate kfree() in the error case in eth_configure because platform_device_unregister frees buffers that the error cases following tried to free again. The pcap initialization routine wasn't doing the proper printk of its information, causing a printk of the first part of that line to be unterminated by a newline. The pcap code had a bunch of style violations, which are now fixed. pcap_setup wasn't returning false when it detected an unrecognized option. The printks in pcap_user all got UM_KERN_BLAH prepended to their format strings. pcap_remove now checks for a non-NULL pcap structure before it calls pcap_close. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: an idle system should have zero load averageJeff Dike2007-05-08
| | | | | | | | | | | | | | The ever-vigilant users of linode.com noticed that an idle 2.6 UML has a persistent load average of ~.4. It turns out that because the UML timer handler processed softirqs before actually delivering the tick, the tick was counted in the context of the idle thread about half the time. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fix prototypesPaolo 'Blaisorblade' Giarrusso2007-05-07
| | | | | | | | | Declare strlcpy and strlcat more correctly. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: virtualized time fixJeff Dike2007-05-07
| | | | | | | | | | | | | With the current timekeeping, !CONFIG_UML_REAL_TIME_CLOCK has inconsistent behavior. Previously, gettimeofday could be (and was) isolated from the clock ticking. Now, it's not, so when CONFIG_UML_REAL_TIME_CLOCK is disabled, gettimeofday must progress in lockstep with the clock, making it fully virtual. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: out of tmpfs space error clarificationJeff Dike2007-05-07
| | | | | | | | | | It turns out that the message complaining about a lack of tmpfs space on the host can be misunderstood as referring to the UML. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: only flush areas covered by VMAJeff Dike2007-05-07
| | | | | | | | | When doing a full address space flush, only look at areas covered by a VMA. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: more page fault path trimmingJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More trimming of the page fault path. Permissions are passed around in a single int rather than one bit per int. The permission values are copied from libc so that they can be passed to mmap and mprotect without any further conversion. The register sets used by do_syscall_stub and copy_context_skas0 are initialized once, at boot time, rather than once per call. wait_stub_done checks whether it is getting the signals it expects by comparing the wait status to a mask containing bits for the signals of interest rather than comparing individually to the signal numbers. It also has one check for a wait failure instead of two. The caller is expected to do the initial continue of the stub. This gets rid of an argument and some logic. The fname argument is gone, as that can be had from a stack trace. user_signal() is collapsed into userspace() as it is basically one or two lines of code afterwards. The physical memory remapping stuff is gone, as it is unused. flush_tlb_page is inlined. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: eliminate a piece of debugging codeJeff Dike2007-05-07
| | | | | | | | | I missed removing another piece of debugging in an earlier patch. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: speed page fault pathJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | Give the page fault code a specialized path. There is only one page to look at, so there's no point in going into the general page table walking code. There's only going to be one host operation, so there are no opportunities for merging. So, we go straight to the pte we want, figure out what needs doing, and do it. While I was in here, I fixed the wart where the address passed to unmap was a void *, but an unsigned long to map and protect. This gives me just under 10% on a kernel build. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: aIO deadlock avoidanceJeff Dike2007-05-07
| | | | | | | | | | Allow deadlocks to be avoided in the AIO code by setting the pipe to the I/O thread non-blocking. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: rename os_{read_write}_file_k back to os_{read_write}_fileJeff Dike2007-05-07
| | | | | | | | | | Rename os_{read_write}_file_k back to os_{read_write}_file, delete the originals and their bogus infrastructure, and fix all the callers. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove debugging remnantsJeff Dike2007-05-07
| | | | | | | | | I accidentally left the remnants of some debugging in an earlier patch. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: formatting fixes around os_{read_write}_file callersJeff Dike2007-05-07
| | | | | | | | | | Formatting fixes ahead of renaming os_{read_write}_file_k to os_{read_write}_file and fixing all the callers. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: change remaining callers of os_{read_write}_fileJeff Dike2007-05-07
| | | | | | | | | | Convert all remaining os_{read_write}_file users to use the simple {read,write} wrappers, os_{read_write}_file_k. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: don't try to handle signals on initial process stackJeff Dike2007-05-07
| | | | | | | | | | | | | | | | Code running on the initial UML stack can't receive or process signals since current must be valid when IRQs are handled, and there is no current for this stack. So, instead of using UML_LONGJMP and UML_SETJMP, which are careful to save and restore signal state, and, as a side-effect, handle any deferred signals, start_idle_thread must use the bare equivalents, which don't do anything with signals. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: dump core on panicJeff Dike2007-05-07
| | | | | | | | | | Dump core after a panic. This will provide better debugging information than is currently available. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fixup allocation in the ubd driverPeter Zijlstra2007-05-07
| | | | | | | | | | Sanitise gfp flags; it actually is an atomic context, so drop the GFP_KERNEL part. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: send pointers instead of structures to I/O threadJeff Dike2007-05-07
| | | | | | | | | | | | | | Instead of writing entire structures between UML and the I/O thread, we send pointers. This cuts down on the amount of data being copied and possibly allows more requests to be pending between the two. This requires that the requests be kmalloced and freed instead of living on the stack. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: batch I/O requestsJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | Send as many I/O requests to the I/O thread as possible, even though it will still only handle one at a time. This provides an opportunity to reduce latency by starting one request before the previous one has been finished in the driver. Request handling is somewhat modernized by requesting sg pieces of a request and handling them separately, finishing off the entire request after all the pieces are done. When a request queue stalls, normally because its pipe to the I/O thread is full, it is put on the restart list. This list is processed by starting up the queues on it whenever there is some indication that progress might be possible again. Currently, this happens in the driver interrupt routine. Some requests have been finished, so there is likely to be room in the pipe again. This almost doubles throughput when copying data between devices, but made no noticable difference on anything else I tried. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: convert libc layer to call read and writeJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | | This patch converts calls in the os layer to os_{read,write}_file to calls directly to libc read() and write() where it is clear that the I/O buffer is in the kernel. We can do that here instead of calling os_{read,write}_file_k since we are in libc code and can call libc directly. With the change in the calls, error handling needs to be changed to refer to errno directly rather than the return value of the call. CATCH_EINTR wrappers were also added where needed. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tidy libc codeJeff Dike2007-05-07
| | | | | | | | | | | | | | | | This patch lays some groundwork for the next one, which converts calls to os_{read,write}_file into {read,write}, by doing some tidying in the affected areas. do_not_aio gets restructured to make the final result a bit cleaner. There are also whitespace and other formatting fixes, fixes in error messages, and a typo fix. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: start fixing os_read_file and os_write_fileJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch starts the removal of a very old, very broken piece of code. This stems from the problem of passing a userspace buffer into read() or write() on the host. If that buffer had not yet been faulted in, read and write will return -EFAULT. To avoid this problem, the solution was to fault the buffer in before the system call by touching the pages that hold the buffer by doing a copy-user of a byte to each page. This is obviously bogus, but it does usually work, in tt mode, since the kernel and process are in the same address space and userspace addresses can be accessed directly in the kernel. In skas mode, where the kernel and process are in separate address spaces, it is completely bogus because the userspace address, which is invalid in the kernel, is passed into the system call instead of the corresponding physical address, which would be valid. Here, it appears that this code, on every host read() or write(), tries to fault in a random process page. This doesn't seem to cause any correctness problems, but there is a performance impact. This patch, and the ones following, result in a 10-15% performance gain on a kernel build. This code can't be immediately tossed out because when it is, you can't log in. Apparently, there is some code in the console driver which depends on this somehow. However, we can start removing it by switching the code which does I/O using kernel addresses to using plain read() and write(). This patch introduces os_read_file_k and os_write_file_k for use with kernel buffers and converts all call locations which use obvious kernel buffers to use them. These include I/O using buffers which are local variables which are on the stack or kmalloc-ed. Later patches will handle the less obvious cases, followed by a mass conversion back to the original interface. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove unused x86_64 codeJeff Dike2007-05-07
| | | | | | | | | | It turns out that essentially none of the x86_64 bugs.c is needed. So, we can delete most of it. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: speed up page table walkingJeff Dike2007-05-07
| | | | | | | | | | | | The previous page table walking code was horribly inefficient. This patch replaces it with code taken from elsewhere in the kernel. Forking from bash is now ~5% faster and page faults are handled ~10% faster. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: dump registers on ptrace or wait failureJeff Dike2007-05-07
| | | | | | | | | | Provide a register dump if handle_trap fails. Abstract out ptrace_dump_regs since it now has two callers. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: drivers get release methodsJeff Dike2007-05-07
| | | | | | | | | | | | Define release methods for the ubd and net drivers. They contain as much of the remove methods as make sense. All error checking must have already been done as well as anything else that might be holding a reference on the device kobject. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: delete HOST_FRAME_SIZEJeff Dike2007-05-07
| | | | | | | | | HOST_FRAME_SIZE isn't used any more. It has been replaced with MAX_REG_NR. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: irq locking commentaryJeff Dike2007-05-07
| | | | | | | | | Locking commentary. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: comment early boot lockingJeff Dike2007-05-07
| | | | | | | | | | | Commentary about missing locking. Also got rid of uml_start because it was pointless. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: kernel segfaults should dump proper registersJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | If there's a segfault inside the kernel, we want a dump of the registers at the point of the segfault, not the registers at the point of calling panic or the last userspace registers. sig_handler_common_skas now uses a static register set in the case of a SIGSEGV to avoid messing up the process registers if the segfault turns out to be non-fatal. The architecture sigcontext-to-pt_regs copying code was repurposed to copy data out of the SEGV stack frame. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tidy fault codeJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | | Tidying in preparation for the segfault register dumping patch which follows. void * pointers are changed to union uml_pt_regs *. This makes the types match reality, except in arch_fixup, which is changed to operate on a union uml_pt_regs. This fixes a bug in the call from segv_handler, which passes a union uml_pt_regs, to segv, which expects to pass a struct sigcontext to arch_fixup. Whitespace and other style fixes. There's also a errno printk fix. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: kernel_thread shouldn't panicJeff Dike2007-05-07
| | | | | | | | | | kernel_thread() should just return an error value on do_fork failure, not panic. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove page_size()Jeff Dike2007-05-07
| | | | | | | | | | | | userspace code used to have to call the kernelspace function page_size() in order to determine the value of the kernel's PAGE_SIZE. Since this is now available directly from kern_constants.h as UM_KERN_PAGE_SIZE, page_size() can be deleted and calls changed to use the constant. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tidy process.cJeff Dike2007-05-07
| | | | | | | | | | | | | | | | | | Clean up arch/um/kernel/process.c: - lots of return(x); -> return x; conversions - a number of the small functions are either unused, in which case they are gone, along any declarations in a header, or could be made static. - current_pid is ifdefed on CONFIG_MODE_TT and its declaration is ifdefed on both CONFIG_MODE_TT and UML_CONFIG_MODE_TT because we don't know whether it's being used in a userspace or kernel file. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: no locking needed in tls.cJeff Dike2007-05-07
| | | | | | | | | | | Comment the lack of locking on a couple of globals. Also fix the formatting of __setup_host_supports_tls. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: speed up execJeff Dike2007-05-07
| | | | | | | | | | | | | flush_thread doesn't need to do a full page table walk in order to clear the address space. It knows what the end result needs to be, so it can call unmap directly. This results in a 10-20% speedup in an exec from bash. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fix umid in xterm titlesDavide Brini2007-05-07
| | | | | | | | | | Calls lines_init() *after* xterm_title is modified to include umid. Signed-off-by: Davide Brini <davide.brini@unibo.it> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: Replace one-element array with zero-element arrayPaolo 'Blaisorblade' Giarrusso2007-05-07
| | | | | | | | | | | | | | | To look at users I did: $ find arch/um/ include/asm-um -name '*.[ch]'|xargs grep -r 'net_kern\.h' +-l|xargs grep '\<user\>' Most users just cast user to the appropriate pointer, the remaining ones are fixed here. In net_kern.c, I'm almost sure that save trick is not needed anymore, but I've not verified it. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: Eliminate temporary buffer in eth_configurePaolo 'Blaisorblade' Giarrusso2007-05-07
| | | | | | | | | | | | | Avoid using the temporary buffer introduced by previous patch to hold the device name. Btw, avoid leaking device on an error path. Other error paths may need cleanup. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>