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* uml: track and make up lost ticksJeff Dike2008-05-132-4/+51
| | | | | | | | | | | | Alarm delivery could be noticably late in the !CONFIG_NOHZ case because lost ticks weren't being taken into account. This is now treated more carefully, with the time between ticks being calculated and the appropriate number of ticks delivered to the timekeeping system. Cc: Nix <nix@esperi.org.uk> 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: random driver fixesJeff Dike2008-05-131-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The random driver would essentially hang if the host's /dev/random returned -EAGAIN. There was a test of need_resched followed by a schedule inside the loop, but that didn't help and it's the wrong way to work anyway. The right way is to ask for an interrupt when there is input available from the host and handle it then rather than polling. Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup when there's randomness available again and sleeps. The interrupt routine just wakes up whatever processes are sleeping on host_read_wait. There is an atomic_t, host_sleep_count, which counts the number of processes waiting for randomness. When this reaches zero, the interrupt is disabled. An added complication is that async I/O notification was only recently added to /dev/random (by me), so essentially all hosts will lack it. So, we use the sigio workaround here, which is to have a separate thread poll on the descriptor and send an interrupt when there is input on it. This mechanism is activated when a process gets -EAGAIN (activating this multiple times is harmless, if a bit wasteful) and deactivated by the last process still waiting. The module name was changed from "random" to "hw_random" in order for udev to recognize it. The sigio workaround needed some changes. sigio_broken was added for cases when we know that async notification doesn't work. This is now called from maybe_sigio_broken, which deals with pts devices. 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: fix build when SLOB is enabledJeff Dike2008-05-134-7/+7
| | | | | | | | | | | | | | | | | | Reintroduce uml_kmalloc for the benefit of UML libc code. The previous tactic of declaring __kmalloc so it could be called directly from the libc side of the house turned out to be getting too intimate with slab, and it doesn't work with slob. So, the uml_kmalloc wrapper is back. It calls kmalloc or whatever that translates into, and libc code calls it. kfree is left alone since that still works, leaving a somewhat inconsistent API. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tidy ptrace interfaceJeff Dike2008-05-131-2/+3
| | | | | | | | | | Tidy the ptrace interface code. Removed a bunch of unused macros. Started converting register sets from arrays of longs to structures. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: style fixesJeff Dike2008-05-131-1/+1
| | | | | | | | | A few random style fixes. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: redo host capability detection and disablingJeff Dike2008-05-131-40/+41
| | | | | | | | | | | | | | | Redo how host capabilities are recorded at startup and disabled on the command line. There are now explicit variables saying what's been disabled by the command line rather than the implicitness of the have_* variable being zero. The capability variables now start at zero and are set to one as their capabilities are found to be present on the host. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch/um/os-Linux/sys-i386/task_size.c: improve a bitWANG Cong2008-04-281-4/+8
| | | | | | | | | | Improve this code a bit: check sigaction's return value and remove a useless fflush(). Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch/um/os-Linux/start_up.c: various improvements.WANG Cong2008-04-281-8/+6
| | | | | | | | | | | - lets ptrace_child become void - adds checking for the return value of change_sig - moves errors info into stderr instead of stdout. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fix build errorIngo Molnar2008-04-261-0/+1
| | | | | | | | | fix: arch/um/os-Linux/helper.c: In function 'run_helper': arch/um/os-Linux/helper.c:73: error: 'PATH_MAX' undeclared (first use in this function) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* uml: fix FP register corruptionJeff Dike2008-02-233-0/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ee3d9bd4de1ed93d2a7ee41c331ed30a1c7b8acd ("uml: simplify SIGSEGV handling"), while greatly simplifying the kernel SIGSEGV handler that runs in the process address space, introduced a bug which corrupts FP state in the process. Previously, the SIGSEGV handler called the sigreturn system call by hand - it couldn't return through the restorer provided to it because that could try to call the libc restorer which likely wouldn't exist in the process address space. So, it blocked off some signals, including SIGUSR1, on entry to the SIGSEGV handler, queued a SIGUSR1 to itself, and invoked sigreturn. The SIGUSR1 was delivered, and was visible to the UML kernel after sigreturn finished. The commit eliminated the signal masking and the call to sigreturn. The handler simply hits itself with a SIGTRAP to let the UML kernel know that it is finished. UML then restores the process registers, which effectively longjmps the process out of the signal handler, skipping sigreturn's restoring of register state and the signal mask. The bug is that the host apparently sets used_fp to 0 when it saves the process FP state in the sigcontext on the process signal stack. Thus, when the process is longjmped out of the handler, its FP state is corrupt because it wasn't saved on the context switch to the UML kernel. This manifested itself as sleep hanging. For some reason, sleep uses floating point in order to calculate the sleep interval. When a page fault corrupts its FP state, it is faked into essentially sleeping forever. This patch saves the FP state before entering the SIGSEGV handler and restores it afterwards. 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: improved error handling while locating temp dirJim Meyering2008-02-081-9/+6
| | | | | | | | | | | | | | * arch/um/os-Linux/mem.c (make_tempfile): Don't deref NULL upon failed malloc. * arch/um/os-Linux/mem.c (make_tempfile): Handle NULL tempdir. Don't let a long tempdir (e.g., via TMPDIR) provoke heap corruption. [ jdike - formatting cleanups, deleted obsolete comment ] Signed-off-by: Jim Meyering <meyering@redhat.com> 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: style fixes in arch/um/os-LinuxJeff Dike2008-02-0813-118/+98
| | | | | | | | | | | | | | | | | | | | | Style changes under arch/um/os-Linux: include trimming CodingStyle fixes some printks needed severity indicators make_tempfile turns out not to be used outside of mem.c, so it is now static. Its declaration in tempfile.h is no longer needed, and tempfile.h itself is no longer needed. create_tmp_file was also made static. checkpatch moans about an EXPORT_SYMBOL in user_syms.c which is part of a macro definition - this is copying a bit of kernel infrastructure into the libc side of UML because the kernel headers can't be included there. 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: runtime host VMSPLIT detectionJeff Dike2008-02-084-2/+127
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is needed on i386 if UML is to run on hosts with varying VMSPLITs without recompilation. TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of an include of pgtable.h from processor.h, which can cause include loops. On i386, task_size is calculated early in boot by probing the address space in a binary search to figure out where the boundary between usable and non-usable memory is. This tries to make sure that a page that is considered to be in userspace is, or can be made, read-write. I'm concerned about a system-global VDSO page in kernel memory being hit and considered to be a userspace page. On x86_64, task_size is just the old value of CONFIG_TOP_ADDR. A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in arch/um/Makefile are also gone. I noticed and fixed a missing extern in os.h when adding os_get_task_size. Note: This has been revised to fix the 32-bit UML on 64-bit host bug that Miklos ran into. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: move register initializationJeff Dike2008-02-051-3/+7
| | | | | | | | | | Calling init_registers inside the skas3 checking causes mysterious crashes if it doesn't happen because the skas3 checking is bypassed. This patch moves it to os_early_checks. 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: add newlines to printksJeff Dike2008-02-051-4/+4
| | | | | | | | Some printks were missing newlines. 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: implement O_APPENDJeff Dike2008-02-051-0/+2
| | | | | | | | The .a flags in openflags never had an implementation. 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: remove init_irq_signalsJeff Dike2008-02-052-12/+4
| | | | | | | | | | | init_irq_signals doesn't need to be called from the context of a new process. It initializes handlers, which are useless in process context. With that call gone, init_irq_signals has only one caller, so it can be inlined into init_new_thread_signals. 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: signal handling tidyingJeff Dike2008-02-051-21/+12
| | | | | | | | | | | | | | | This patch tidies the signal handling code slightly. pending is renamed to signals_pending for symmetry with signals_enabled. remove_sigstack was unused, so can be deleted. The value of change_sig was never used, so it is now void and the return value is not calculated any more. 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: clean up sig_handler_common_skasJeff Dike2008-02-051-45/+18
| | | | | | | | | | | | | | | | | | | | | | | | sig_handler_common_skas needs significant modernization, starting with its name and storage class. There is no need to hide the true type of the sigcontext pointer, so the void * dummy parameter can be replaced with a sigcontext *sc. The array of uml_pt_regs structs used in the page fault case are gone, replaced by a local variable. This is also used in the non-segfault case instead of the copy in the task_struct. Since it's local, the special handling of the is_user flag can go away. There hasn't been any special treatment of SIGUSR1 in ages, so the line that enables it can be deleted. The special treatment of SIGSEGV similarly goes away, but to compensate, SA_NODEFER is added to sa_mask when registering a signal handler. 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: move sig_handler_common_skasJeff Dike2008-02-053-76/+65
| | | | | | | | | | | | | This patch moves sig_handler_common_skas from arch/um/os-Linux/skas/trap.c to its only caller in arch/um/os-Linux/signal.c. trap.c is now empty, so it can be removed. This is code movement only - the significant cleanup needed here is done in the next patch. 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: don't allow processes to call into stubJeff Dike2008-02-051-0/+3
| | | | | | | | | | | | | Kill a process that tries to branch into a stub and execute a system call. There are no security implications here - a system call in a stub is treated the same as a system call anywhere else. But if a process is trying to branch into a stub, either it is trying something nasty or it has gone haywire, so it's a good idea to get rid of it in either case. 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: tidy helper codeJeff Dike2008-02-053-46/+32
| | | | | | | | | | | | | | | | | | | | | | | | Style fixes to arch/um/os/helper.c and tidying up the breakpoint fix a bit. helper.c gets all the usual style fixes - updated copyright all printks get severities Also - errval changes to err in helper_child fixed an obsolete comment run_helper was killing a child process which is guaranteed to be dead or dying anyway Removed the nohang and pname arguments from helper_wait and fixed the declaration and callers. nohang was used only in the slirp driver and I don't think it was needed. I think pname was a bit of overkill in putting out an error message when something goes wrong. 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: use barrier() instead of mb()Jeff Dike2008-02-051-20/+8
| | | | | | | | | | | | | | | | signals_enabled and pending have requirements on the order in which they are modified. This used to be done by declaring them volatile and putting an mb() where the ordering requirements were in effect. After getting a better (I hope) understanding of how to do this correctly, the volatile declarations are gone and the mb()'s replaced by barrier()'s. One of the mb()'s was deleted because I see no problematic writes that could be re-ordered past that point. 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: install panic notifier earlierJeff Dike2008-02-051-2/+0
| | | | | | | | | | | | | | | | | | | | It turns out that if there's a panic early enough, UML will just sit there in the LED-blinking loop because the panic notifier hadn't been installed yet. This patch installs it earlier. It also fixes the problem which exposed the hang, namely that if you give UML a zero-sized initrd, it will ask alloc_bootmem for zero bytes, and that will cause the panic. While I was in initrd.c, I gave it a style makeover. Prompted by checkpatch, I moved a couple extern declarations of uml_exitcode to kern_util.h. 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 setjmp_wrapperJeff Dike2008-02-051-15/+0
| | | | | | | | | | | | | | | | | setjmp_wrapper existed to provide setjmp to kernel code when UML used libc's setjmp and longjmp. Now that UML has its own implementation, this isn't needed and kernel code can invoke setjmp directly. do_buffer_op is massively cleaned up since it is no longer a callback from setjmp_wrapper and given a va_list from which it must extract its arguments. The actual setjmp is moved from buffer_op to do_op_one_page because the copy operation is inside an atomic section (kmap_atomic to kunmap_atomic) and it shouldn't be longjmp-ed out of. 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: style fixes in file.cJeff Dike2008-02-051-114/+118
| | | | | | | | | | | | | | | | arch/um/os-Linux/file.c needed some style work - updated the copyright cleaned up the includes CodingStyle fixes added some missing CATCH_EINTRs os_set_owner was unused, so it is gone all printks now have severities fcntl(F_GETFL) was being called without checking the return removed an obsolete comment 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: miscellaneous code cleanupsJeff Dike2008-02-052-28/+13
| | | | | | | | | | | | | | | Code tidying - the pid field of struct irq_fd isn't used, so it is removed os_set_fd_async needed to read flags before changing them, it doesn't need a pid passed in because it can call getpid itself, and a block of unused code needed deleting os_get_exec_close was unused, so it is removed ptrace_child called _exit for historical reasons which are no longer valid, so just calls exit instead 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: syle fixes in arch/um/os-LinuxJeff Dike2008-02-052-118/+150
| | | | | | | | | | | | | | | Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c: Updated copyrights trimmed includes added severity indicators to printks CodingStyle fixes turned an bunch of panics into printks call some libc functions directly instead of going through the os_* wrappers 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: kill processes instead of panicing kernelJeff Dike2008-02-053-102/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UML was panicing in the case of failures of libc calls which shouldn't happen. This is an overreaction since a failure from libc doesn't normally mean that kernel data structures are in an unknown state. Instead, the current process should just be killed if there is no way to recover. The case that prompted this was a failure of PTRACE_SETREGS restoring the same state that was read by PTRACE_GETREGS. It appears that when a process tries to load a bogus value into a segment register, it segfaults (as expected) and the value is actually loaded and is seen by PTRACE_GETREGS (not expected). This case is fixed by forcing a fatal SIGSEGV on the process so that it immediately dies. fatal_sigsegv was added for this purpose. It was declared as noreturn, so in order to pursuade gcc that it actually does not return, I added a call to os_dump_core (and declared it noreturn) so that I get a core file if somehow the process survives. All other calls in arch/um/os-Linux/skas/process.c got the same treatment, with failures causing the process to die instead of a kernel panic, with some exceptions. userspace_tramp exits with status 1 if anything goes wrong there. That will cause start_userspace to return an error. copy_context_skas0 and map_stub_pages also now return errors instead of panicing. Callers of thes functions were changed to check for errors and do something appropriate. Usually that's to return an error to their callers. check_skas3_ptrace_faultinfo just exits since that's too early to do anything else. save_registers, restore_registers, and init_registers now return status instead of panicing on failure, with their callers doing something appropriate. There were also duplicate declarations of save_registers and restore_registers in os.h - these are gone. I noticed and fixed up some whitespace damage. 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: use ptrace directly in libc codeJeff Dike2008-02-052-12/+12
| | | | | | | | | | | | | Some register accessor cleanups - userspace() was calling restore_registers and save_registers for no reason, since userspace() is on the libc side of the house, and these add no value over calling ptrace directly init_thread_registers and get_safe_registers were the same thing, so init_thread_registers is gone 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: simplify SIGSEGV handlingJeff Dike2008-02-051-7/+4
| | | | | | | | | | | | | | | | | | | Simplify the page fault stub by not masking signals while it is running. This allows it to signal that it is done by executing an instruction which will generate a SIGTRAP (int3 on x86) rather than running sigreturn by hand after queueing a blocked SIGUSR1. userspace_tramp now no longer puts anything in the SIGSEGV sa_mask, but it does add SA_NODEFER to sa_flags so that SIGSEGV is still enabled after the signal handler fails to run sigreturn. SIGWINCH is just blocked so that we don't have to deal with it and the signal masks used by wait_stub_done are updated to reflect the smaller number of signals that it has to worry about. 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: convert functions to voidKarol Swietlicki2008-02-051-3/+1
| | | | | | | | | | | This patch changes a few functions into returning void. The return values were not used anyway, so I think it should not be a problem. Also removed a little leftover bit from TT mode. Signed-off-by: Karol Swietlicki <magotari@gmail.com> 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>
* arch/um: remove duplicate includesLucas Woods2008-02-051-1/+0
| | | | | | | Signed-off-by: Lucas Woods <woodzy@gmail.com> 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: tidy kern_util.hJeff Dike2008-02-0512-64/+46
| | | | | | | | | | | | | | | | | | | | | Tidy kern_util.h. It turns out that most of the function declarations aren't used, so they can go away. os.h no longer includes kern_util.h, so files which got it through os.h now need to include it directly. A number of other files never needed it, so these includes are deleted. The structure which was used to pass signal handlers from the kernel side to the userspace side is gone. Instead, the handlers are declared here, and used directly from libc code. This allows arch/um/os-Linux/trap.c to be deleted, with its remnants being moved to arch/um/os-Linux/skas/trap.c. arch/um/os-Linux/tty.c had its inclusions changed, and it needed some style attention, so it got tidied. 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: const and other tidyingWANG Cong2008-02-053-5/+6
| | | | | | | | | | | This patch also does some improvements for uml code. Improvements include dropping unnecessary cast, killing some unnecessary code and still some constifying for pointers etc.. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> 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: code tidying under arch/um/os-LinuxWANG Cong2008-02-055-14/+22
| | | | | | | | | | | | | This patch contains varied fixes and improvements for some files under arch/um/os-Linux/, such as a typo fix in a perror message, a missing argument fix for a printf, some constifying for pointers and so on. [ jdike - made sigprocmask failure return -errno instead of -1 ] Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> 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: stop gdb from deleting breakpoints when running UMLStanislaw Gruszka2007-12-177-30/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes when UML is debugged gdb miss breakpoints. When process traced by gdb do fork, debugger remove breakpoints from child address space. There is possibility to trace more than one fork, but this not work with UML, I guess (only guess) there is a deadlock - gdb waits for UML and UML waits for gdb. When clone() is called with SIGCHLD and CLONE_VM flags, gdb see this as PTRACE_EVENT_FORK not as PTRACE_EVENT_CLONE and remove breakpoints from child and at the same time from traced process, because either have the same address space. Maybe it is possible to do fix in gdb, but I'm not sure if there is easy way to find out if traced and child processes share memory. So I do fix for UML, it simply do not call clone() with both SIGCHLD and CLONE_VM flags together. Additionally __WALL flag is used for waitpid() to assure not miss clone and normal process events. [ jdike - checkpatch fixes ] Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> 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: after_sleep_interval should return somethingJeff Dike2007-12-031-0/+1
| | | | | | | | I forgot to have an int-returning function actually return something. 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: fix !NO_HZ busy-loopJeff Dike2007-11-291-3/+51
| | | | | | | | | | | | | | | | | | With NO_HZ disabled, the UML idle loop effectively becomes a busy loop, as it will sleep for no time. The cause was forgetting to restart the tick after waking up from sleep. It was disabled before sleeping, and the remaining time used as the interval to sleep. So, the tick needs to be restarted when nanosleep finishes. This is done by introducing after_sleep_interval, which is empty in the NO_HZ case, but which sets the tick starting in the !NO_HZ case. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: fix recvmsg return value checkingJeff Dike2007-11-141-2/+1
| | | | | | | | | | Stupid bug - we need to compare the return value of recvmsg to the value of iov_len, not its size. This caused port_helper processes not to be killed on shutdown on x86_64 because the pids weren't being passed out properly. 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: definitively kill subprocesses on panicLepton Wu2007-10-162-1/+39
| | | | | | | | | | | | | | | | | | In a stock 2.6.22.6 kernel, poweroff a user mode linux guest (2.6.22.6 running in skas0 mode) will halt the host linux. I think the reason is the kernel thread abort because of a bug. Then the sys_reboot in process of user mode linux guest is not trapped by the user mode linux kernel and is executed by host. I think it is better to make sure all of our children process to quit when user mode linux kernel abort. [ jdike - the kernel process needs to ignore SIGTERM, plus the waitpid/kill loop is needed to make sure that all of our children are dead before the kernel exits ] Signed-off-by: Lepton Wu <ytht.net@gmail.com> 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: fix stub address calculationsJeff Dike2007-10-162-14/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the cold. I'd rather not duplicate the four known host vmsplit cases for each of these symbols. I'd also like to calculate them based on the highest userspace address. The Kconfig language seems not to allow calculation of hex constants, so I moved this to as-layout.h. CONFIG_STUB_CODE, CONFIG_STUB_DATA, and CONFIG_STUB_START are now gone. In their place are STUB_CODE, STUB_DATA, and STUB_START in as-layout.h. i386 and x86_64 seem to differ as to whether an unadorned constant is an int or a long, so I cast them to unsigned long so they can be printed consistently. However, they are also used in stub.S, where C types don't work so well. So, there are ASM_ versions of these constants for use in stub.S. I also ifdef-ed the non-asm-friendly portion of as-layout.h. With this in place, most of the rest of this patch is changing CONFIG_STUB_* to STUB_*, except in stub.S, where they are changed to ASM_STUB_*. defconfig has the old symbols deleted. I also print these addresses out in case there is any problem mapping them on the host. The two stub.S files had some trailing whitespace, so that is cleaned up here. [akpm@linux-foundation.org: coding-style fixes] 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: network driver MTU cleanupsJeff Dike2007-10-164-46/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | A bunch of MTU-related cleanups in the network code. First, there is the addition of the notion of a maximally-sized packet, which is the MTU plus headers. This is used to size the skb that will receive a packet. This allows ether_adjust_skb to go away, as it was used to resize the skb after it was allocated. Since the skb passed into the low-level read routine is no longer resized, and possibly reallocated, there, they (and the write routines) don't need to get an sk_buff **. They just need the sk_buff * now. The callers of ether_adjust_skb still need to do the skb_put, so that's now inlined. The MAX_PACKET definitions in most of the drivers are gone. The set_mtu methods were all the same and did nothing, so they can be removed. The ethertap driver had a typo which doubled the size of the packet rather than adding two bytes to it. It also wasn't defining its setup_size, causing a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc was dereferenced. 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: network formattingJeff Dike2007-10-166-137/+123
| | | | | | | | | | | | | | | | Style and other non-functional changes in the UML networking code, including include tidying style violations copyright updates printks getting severities userspace code calling libc directly rather than using the os_* wrappers There's also a exit path cleanup in the pcap driver. 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: use *SEC_PER_*SEC constantsJeff Dike2007-10-162-11/+13
| | | | | | | | | | | | | | There are various uses of powers of 1000, plus the odd BILLION constant in the time code. However, there are perfectly good definitions of *SEC_PER_*SEC in linux/time.h which can be used instaed. These are replaced directly in kernel code. Userspace code imports those constants as UM_*SEC_PER_*SEC and uses these. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: eliminate SIGALRMJeff Dike2007-10-167-35/+17
| | | | | | | | | | | | | Now that ITIMER_REAL is no longer used, there is no need for any use of SIGALRM whatsoever. This patch removes all mention of it. In addition, real_alarm_handler took a signal argument which is now always SIGVTALRM. So, that is gone. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: time build fixJeff Dike2007-10-161-3/+19
| | | | | | | | | | | | | | | | Put back an implementation of timeval_to_ns in arch/um/os-Linux/time.c. tglx pointed out in his review of tickless support that there was a perfectly good implementation of it in linux/time.h. The problem is that this is userspace code which can't pull in kernel headers and there doesn't seem to be a libc version. So, I'm copying the version from linux/time.h rather than resurrecting my version. This causes some declaration changes as it now returns a signed value rather than an unsigned value. 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 interrupts in the idle loopJeff Dike2007-10-162-46/+11
| | | | | | | | | | | | | | | | | | | Now, the idle loop now longer needs SIGALRM firing - it can just sleep for the requisite amount of time and fake a timer interrupt when it finishes. Any use of ITIMER_REAL now goes away. disable_timer only turns off ITIMER_VIRTUAL. switch_timers is no longer needed, so it, and all calls, goes away. disable_timer now returns the amount of time remaining on the timer. default_idle uses this to tell idle_sleep how long to sleep. idle_sleep will call alarm_handler if nanosleep returns 0, which is the case if it didn't return early due to an interrupt. Otherwise, it just returns. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: tickless supportJeff Dike2007-10-162-5/+39
| | | | | | | | | | | | | | | | | | | | | | | | Enable tickless support. CONFIG_TICK_ONESHOT and CONFIG_NO_HZ are enabled. itimer_clockevent gets CLOCK_EVT_FEAT_ONESHOT and an implementation of .set_next_event. CONFIG_UML_REAL_TIME_CLOCK goes away because it only makes sense when there is a clock ticking away all the time. timer_handler now just calls do_IRQ once without trying to figure out how many ticks to emulate. The idle loop now needs to turn ticking on and off. Userspace ticks keep happening as usual. However, the userspace loop keep track of when the next wakeup should happen and suppresses process ticks until that happens. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: GENERIC_CLOCKEVENTS supportJeff Dike2007-10-161-4/+0
| | | | | | | | | | | | | | | | | | Enable CONFIG_GENERIC_CLOCKEVENTS. timer_irq gets its name changed to timer_handler, and becomes the recipient of timer signals. The clock_event_device is set up to imitate the current ticking clock, i.e. CLOCK_EVT_FEAT_ONESHOT is not enabled yet. disable_timer now doesn't ignore SIGALRM and SIGVTALRM because that breaks delay calibration. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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