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* x86, um: take arch/um/include/* out of the wayAl Viro2008-10-221-304/+0
| | | | | | | | | We can't just plop asm/* into it - userland helpers are built with it in search path and seeing asm/* show up there suddenly would be a bad idea. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* uml: deal with inaccessible address space startTom Spink2008-06-061-1/+1
| | | | | | | | | | | | | | | | | | | | | This patch makes os_get_task_size locate the bottom of the address space, as well as the top. This is for systems which put a lower limit on mmap addresses. It works by manually scanning pages from zero onwards until a valid page is found. Because the bottom of the address space may not be zero, it's not sufficient to assume the top of the address space is the size of the address space. The size is the difference between the top address and bottom address. [jdike@addtoit.com: changed the name to reflect that this function is supposed to return the top of the process address space, not its size and changed the return value to reflect that. Also some minor formatting changes] Signed-off-by: Tom Spink <tspink@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: random driver fixesJeff Dike2008-05-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: runtime host VMSPLIT detectionJeff Dike2008-02-081-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: remove init_irq_signalsJeff Dike2008-02-051-1/+0
| | | | | | | | | | | 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: move sig_handler_common_skasJeff Dike2008-02-051-3/+0
| | | | | | | | | | | | | 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: tidy helper codeJeff Dike2008-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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: eliminate setjmp_wrapperJeff Dike2008-02-051-1/+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 Dike2008-02-051-1/+0
| | | | | | | | | | | | | | | | 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 Dike2008-02-051-2/+1
| | | | | | | | | | | | | | | 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: kill processes instead of panicing kernelJeff Dike2008-02-051-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: convert functions to voidKarol Swietlicki2008-02-051-5/+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>
* uml: tidy kern_util.hJeff Dike2008-02-051-4/+0
| | | | | | | | | | | | | | | | | | | | | 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: code tidying under arch/um/os-LinuxWANG Cong2008-02-051-6/+6
| | | | | | | | | | | | | 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 Gruszka2007-12-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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: use *SEC_PER_*SEC constantsJeff Dike2007-10-161-2/+0
| | | | | | | | | | | | | | 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: time build fixJeff Dike2007-10-161-2/+2
| | | | | | | | | | | | | | | | 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 Dike2007-10-161-3/+2
| | | | | | | | | | | | | | | | | | | 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 Dike2007-10-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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: separate timer initializationJeff Dike2007-10-161-0/+1
| | | | | | | | | | Move timer signal initialization from init_irq_signals to a new function, timer_init. 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: simplify interval settingJeff Dike2007-10-161-1/+1
| | | | | | | | | | | set_interval took a timer type as an argument, but it always specified a virtual timer. So, it is not needed, and it is gone, and set_interval is simplified appropriately. 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: fix timer switchingJeff Dike2007-10-161-1/+1
| | | | | | | | | | | | | | | | | | | | | Fix up the switching between virtual and real timers. The idle loop sleeps, so the timer at that point must be real time. At all other times, the timer must be virtual. Even when userspace is running, and the kernel is asleep, the virtual timer is correct because the process timer will be running and the process timer will be firing. The timer switch used to be in the context switch and timer handler code. This is moved to the idle loop and the signal handler, making it much more clear why it is happening. switch_timers now returns the old timer type so that it may be restored. The signal handler uses this in order to restore the previous timer type when it 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: userspace files should call libc directlyJeff Dike2007-10-161-2/+1
| | | | | | | | | | | | | | | | | | | | | A number of files that were changed in the recent removal of tt mode are userspace files which call the os_* wrappers instead of calling libc directly. A few other files were affected by this, through This patch makes these call glibc directly. There are also style fixes in the affected areas. os_print_error has no remaining callers, so it is deleted. There is a interface change to os_set_exec_close, eliminating a parameter which was always the same. The callers are fixed as well. os_process_pc got its error path cleaned up. 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 os_* usage from userspace filesJeff Dike2007-10-161-1/+0
| | | | | | | | | | | | | | This patch fixes some userspace files which were calling libc through the os_* wrappers. It turns out that there was only one user of os_new_tty_pgrp, so it can be deleted. There are also some style and whitespace fixes in here. 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: get rid of do_longjmpJeff Dike2007-10-161-3/+2
| | | | | | | | | | | | | do_longjmp used to be needed when UML didn't have its own implementation of setjmp and longjmp. They came from libc, and couldn't be called directly from kernel code, as the libc jmp_buf couldn't be imported there. do_longjmp was a userspace function which served to provide longjmp access to kernel code. This is gone, and a number of void * pointers can now be jmp_buf *. 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 pass 3Jeff Dike2007-10-161-9/+7
| | | | | | | | | | | | | | | Formatting changes in the files which have been changed in the course of folding foo_skas functions into their callers. These include: copyright updates header file trimming style fixes adding severity to printks These changes should be entirely non-functional. 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 code made redundant by CHOOSE_MODE removalJeff Dike2007-10-161-3/+3
| | | | | | | | | | | | | | | | | | | | | | This patch makes a number of simplifications enabled by the removal of CHOOSE_MODE. There were lots of functions that looked like int foo(args){ foo_skas(args); } The bodies of foo_skas are now folded into foo, and their declarations (and sometimes entire header files) are deleted. In addition, the union uml_pt_regs, which was a union between the tt and skas register formats, is now a struct, with the tt-mode arm of the union being removed. It turns out that usr2_handler was unused, so it 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: throw out CONFIG_MODE_TTJeff Dike2007-10-161-26/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset throws out tt mode, which has been non-functional for a while. This is done in phases, interspersed with code cleanups on the affected files. The removal is done as follows: remove all code, config options, and files which depend on CONFIG_MODE_TT get rid of the CHOOSE_MODE macro, which decided whether to call tt-mode or skas-mode code, and replace invocations with their skas portions replace all now-trivial procedures with their skas equivalents There are now a bunch of now-redundant pieces of data structures, including mode-specific pieces of the thread structure, pt_regs, and mm_context. These are all replaced with their skas-specific contents. As part of the ongoing style compliance project, I made a style pass over all files that were changed. There are three such patches, one for each phase, covering the files affected by that phase but no later ones. I noticed that we weren't freeing the LDT state associated with a process when it exited, so that's fixed in one of the later patches. The last patch is a tidying patch which I've had for a while, but which caused inexplicable crashes under tt mode. Since that is no longer a problem, this can now go in. This patch: Start getting rid of tt mode support. This patch throws out CONFIG_MODE_TT and all config options, code, and files which depend on it. CONFIG_MODE_SKAS is gone and everything that depends on it is included unconditionally. The few changed lines are in re-written Kconfig help, lines which needed something skas-related removed from them, and a few more which weren't strictly deletions. 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 saving process FP stateJeff Dike2007-10-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Throw out a lot of code dealing with saving and restoring floating-point state. In skas mode, where processes run in a restoring floating-point state on kernel entry and exit is pointless. This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c. Most of what remained is now arch-indpendent, and can be moved up to arch/um/os-Linux/registers.c. Both arches need the jmp_buf accessor get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during sigreturn by getting the fp state using ptrace rather than copying it out of the process sigcontext. After this, it turns out that arch/um/include/skas/mode-skas.h is almost completely unneeded. The declarations in it are variables which either don't exist or which don't have global scope. The one exception is kill_off_processes_skas. If that's removed, this header can be deleted. This uncovered a bug in user.h, which wasn't correctly making sure that a size_t definition was available to both userspace and kernelspace files. 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 recently-moved codeJeff Dike2007-10-161-1/+0
| | | | | | | | | | | | Now that the generic console operations are in a userspace file, we can do the following: directly call into libc instead of through the os_* wrappers eliminate os_window_size since it has only one user 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: simplify helper stack handlingJeff Dike2007-07-161-4/+2
| | | | | | | | | | | | | run_helper and run_helper_thread had arguments which were the same in all callers. run_helper's stack_out was always NULL and run_helper_thread's stack_order was always 0. These are now gone, and the constants folded into the code. Also fixed leaks of the helper stack in the AIO and SIGIO code. 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 task_protectionsJeff Dike2007-05-111-1/+0
| | | | | | | | | | | | | | 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>
* uml: more page fault path trimmingJeff Dike2007-05-071-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: speed page fault pathJeff Dike2007-05-071-1/+1
| | | | | | | | | | | | | | | | | | 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: rename os_{read_write}_file_k back to os_{read_write}_fileJeff Dike2007-05-071-2/+0
| | | | | | | | | | 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: dump core on panicJeff Dike2007-05-071-0/+1
| | | | | | | | | | 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: start fixing os_read_file and os_write_fileJeff Dike2007-05-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: move remaining useful contents of user_util.hJeff Dike2007-05-071-0/+6
| | | | | | | | | | | | | | | | | | | | | Rescue the useful contents of the soon-to-be-gone user-util.h. pty.c now gets ptsname from stdlib.h like it should have always done. CATCH_EINTR is now in os.h, although perhaps all usage should be under os-Linux at some point. get_pty is also in os.h. This patch restores the old definition of ARRAY_SIZE in user.h. This file is included only in userspace files, so there will be no conflict with the kernel's new ARRAY_SIZE. The copy of the kernel's ARRAY_SIZE and associated infrastructure is now gone. 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: host_info tidyingJeff Dike2007-05-071-1/+1
| | | | | | | | | | Move the host_info string from util.c to um_arch.c, where it is actually initialized and used. Also document its lack of locking. Signed-off-by: Jeff Dike <jdike@addtoit.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>
* [PATCH] um: remove dead code about os_usr1_signal() and os_usr1_process()Paolo 'Blaisorblade' Giarrusso2007-03-081-1/+2
| | | | | | | | | os_usr1_signal() is totally unused, os_usr1_process() is used only by TT mode. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> 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>
* [PATCH] uml: x86_64 thread fixesJeff Dike2007-02-111-0/+2
| | | | | | | | | | | | | | | | | | | | | x86_64 needs some TLS fixes. What was missing was remembering the child thread id during clone and stuffing it into the child during each context switch. The %fs value is stored separately in the thread structure since the host controls what effect it has on the actual register file. The host also needs to store it in its own thread struct, so we need the value kept outside the register file. arch_prctl_skas was fixed to call PTRACE_ARCH_PRCTL appropriately. There is some saving and restoring of registers in the ARCH_SET_* cases so that the correct set of registers are changed on the host and restored to the process when it runs again. Signed-off-by: Jeff Dike <jdike@addtoit.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>
* [PATCH] uml: libc-dependent code should call libc directlyJeff Dike2007-02-111-1/+0
| | | | | | | | | | | | | We shouldn't be using the os wrappers from os code - we can use libc directly. This patch replaces wrapper calls with libc calls. It turns out that os_sigio_async had only one caller, which was in startup.c, so that function is moved there and its name changed. Signed-off-by: Jeff Dike <jdike@addtoit.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>
* [PATCH] uml: make execvp safe for our usagePaolo 'Blaisorblade' Giarrusso2006-11-251-0/+2
| | | | | | | | | | | | | | | | | | | | | Reimplement execvp for our purposes - after we call fork() it is fundamentally unsafe to use the kernel allocator - current is not valid there. So we simply pass to our modified execvp() a preallocated buffer. This fixes a real bug and works very well in testing (I've seen indirectly warning messages from the forked thread - they went on the pipe connected to its stdout and where read as a number by UML, when calling read_output(). I verified the obtained number corresponded to "BUG:"). The added use of __cant_sleep() is not a new bug since __cant_sleep() is already used in the same function - passing an atomicity parameter would be better but it would require huge change, stating that this function must not be called in atomic context and can sleep is a better idea (will make sure of this gradually). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: readd forgot prototypePaolo 'Blaisorblade' Giarrusso2006-10-111-0/+1
| | | | | | | | | | This was forgot in a previous patch so UML does not compile with TT mode enabled. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: thread creation tidyingJeff Dike2006-09-271-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fork on UML has always somewhat subtle. The underlying cause has been the need to initialize a stack for the new process. The only portable way to initialize a new stack is to set it as the alternate signal stack and take a signal. The signal handler does whatever initialization is needed and jumps back to the original stack, where the fork processing is finished. The basic context switching mechanism is a jmp_buf for each process. You switch to a new process by longjmping to its jmp_buf. Now that UML has its own implementation of setjmp and longjmp, and I can poke around inside a jmp_buf without fear that libc will change the structure, a much simpler mechanism is possible. The jmpbuf can simply be initialized by hand. This eliminates - the need to set up and remove the alternate signal stack sending and handling a signal the signal blocking needed around the stack switching, since there is no stack switching setting up the jmp_buf needed to jump back to the original stack after the new one is set up In addition, since jmp_buf is now defined by UML, and not by libc, it can be embedded in the thread struct. This makes it unnecessary to have it exist on the stack, where it used to be. It also simplifies interfaces, since the switch jmp_buf used to be a void * inside the thread struct, and functions which took it as an argument needed to define a jmp_buf variable and assign it from the void *. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: mark some tt-mode codeJeff Dike2006-09-271-1/+2
| | | | | | | | | | | Mark a symbol and file as being tt-mode only. This shrinks the binary slightly when tt mode support is compiled out and makes it easier to identity stuff when tt mode is removed. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: timer cleanupsJeff Dike2006-09-261-1/+3
| | | | | | | | | | | | | | | | | | | set_interval returns an error instead of panicing if setitimer fails. Some of its callers now check the return. enable_timer is largely tt-mode-specific, so it is marked as such, and the only skas-mode caller is made to call set-interval instead. user_time_init was a no-value-added wrapper around set_interval, so it is gone. Since set_interval is now called from kernel code, callers no longer pass ITIMER_* to it. Instead, they pass a flag which is converted into ITIMER_REAL or ITIMER_VIRTUAL. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: SIGIO cleanupsJeff Dike2006-09-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Various cleanups in the sigio code. - Removed explicit zero-initializations of a few structures. - Improved some error messages. - An API change - there was an asymmetry between reactivate_fd calling maybe_sigio_broken, which goes through all the machinery of figuring out if a file descriptor supports SIGIO and applying the workaround to it if not, and deactivate_fd, which just turns off the descriptor. This is changed so that only activate_fd calls maybe_sigio_broken, when the descriptor is first seen. reactivate_fd now calls add_sigio_fd, which is symmetric with ignore_sigio_fd. This removes a recursion which makes a critical section look more critical than it really was, obsoleting a big comment to that effect. This requires keeping track of all descriptors which are getting the SIGIO treatment, not just the ones being polled at any given moment, so that reactivate_fd, through add_sigio_fd, doesn't try to tell the SIGIO thread about descriptors it doesn't care about. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: header formatting cleanupsJeff Dike2006-07-141-34/+34
| | | | | | | | Clean up whitespace and return syntax in os.h. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uml: make some symbols staticJeff Dike2006-07-101-1/+0
| | | | | | | | | A few sigio-related things can be made static. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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