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2007-05-11uml: iRQ stacksJeff Dike
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>
2007-05-11uml: tidy IRQ codeJeff Dike
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>
2007-05-11uml: use UM_THREAD_SIZE in userspace codeJeff Dike
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>
2007-05-11uml: remove task_protectionsJeff Dike
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>
2007-05-09uml: turn build warnings into commentsMiklos Szeredi
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>
2007-05-09uml: mark a tt-only functionJeff Dike
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>
2007-05-07uml: more page fault path trimmingJeff Dike
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>
2007-05-07uml: speed page fault pathJeff Dike
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>
2007-05-07uml: aIO deadlock avoidanceJeff Dike
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>
2007-05-07uml: rename os_{read_write}_file_k back to os_{read_write}_fileJeff Dike
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>
2007-05-07uml: don't try to handle signals on initial process stackJeff Dike
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>
2007-05-07uml: dump core on panicJeff Dike
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>
2007-05-07uml: convert libc layer to call read and writeJeff Dike
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>
2007-05-07uml: tidy libc codeJeff Dike
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>
2007-05-07uml: start fixing os_read_file and os_write_fileJeff Dike
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>
2007-05-07uml: dump registers on ptrace or wait failureJeff Dike
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>
2007-05-07uml: kernel segfaults should dump proper registersJeff Dike
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>
2007-05-07uml: tidy fault codeJeff Dike
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>
2007-05-07uml: remove page_size()Jeff Dike
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>
2007-05-07uml: add missing __init declarationsJeff Dike
The build started finding calls from non-init to init functions. These are just cases of init functions not being properly marked, so this patch fixes that. 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>
2007-05-07uml: remove user_util.hJeff Dike
user_util.h isn't needed any more, so delete it and remove all includes 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>
2007-05-07uml: move remaining useful contents of user_util.hJeff Dike
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>
2007-05-07uml: create as-layout.hJeff Dike
This patch moves all the the symbols defined in um_arch.c, which are mostly boundaries between different parts of the UML kernel address space, to a new header, as-layout.h. There are also a few things here which aren't really related to address space layout, but which don't really have a better place to go. 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>
2007-05-07uml: move SIGIO testing to sigio.cJeff Dike
This patch narrows the sigio interface. The boot-time SIGIO testing used to be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed to be global. By moving that code here, those can become static and the declarations moved from user_util.h. os_check_bugs is also here because it only does the SIGIO checking. If it does more, it'll probably move back to start_up.c. 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>
2007-05-07uml: network interface hotplug error handlingJeff Dike
This fixes a number of problems associated with network interface hotplug. The userspace initialization function can fail in some cases, but the failure was never passed back to eth_configure, which proceeded with the configuration. This results in a zombie device that is present, but can't work. This is fixed by allowing the initialization routines to return an error, which is checked, and the configuration aborted on failure. eth_configure failed to check for many failures. Even when it did check, it didn't undo whatever initializations has already happened, so a present, but partially initialized and non-working device could result. It now checks everything that can fail, and bails out, undoing whatever had been done. The return value of eth_configure was always ignored, so it is now just void. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: driver formatting fixesJeff Dike
Fix a bunch of formatting violations in the drivers: return(n) -> return n whitespace fixes emacs formatting comment removal breaking if(foo) return(n) into two lines There are also a couple of errno use bugs: using errno in a printk when the failure put errno into a local variable saving errno after a printk, which can change 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>
2007-05-07uml: print coredump limitsJeff Dike
Print out core dump limits at boot time. This is to allow core dumps to be collected if something goes very wrong and to tell if a core dump isn't going to happen because of a resource limit. 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>
2007-05-07uml: host_info tidyingJeff Dike
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>
2007-05-07uml: formatting fixesJeff Dike
Formatting fixes - style violations whitespace breakage emacs formatting comment removal 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>
2007-05-07uml: delete unused codeJeff Dike
Get rid of a bunch of unused stuff - cpu_feature had no users linux_prog is little-used, so its declaration is moved to the user for easy deletion when the whole file goes away a long-unused debugging aid in helper.c is gone 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>
2007-04-25[SK_BUFF]: Introduce skb_mac_header()Arnaldo Carvalho de Melo
For the places where we need a pointer to the mac header, it is still legal to touch skb->mac.raw directly if just adding to, subtracting from or setting it to another layer header. This one also converts some more cases to skb_reset_mac_header() that my regex missed as it had no spaces before nor after '=', ugh. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-27[PATCH] uml: use correct register file size everywhereJeff Dike
This patch uses MAX_REG_NR consistently to refer to the register file size. FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the ptrace register file size. MAX_REG_NR was introduced as a consistent way to get the number of registers, but wasn't used everywhere it should be. When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because of a corrupted segment register value in the known-good register file. The patch also adds a register dump at that point in case there are any future problems here. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08[PATCH] um: remove dead code about os_usr1_signal() and os_usr1_process()Paolo 'Blaisorblade' Giarrusso
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>
2007-03-06[PATCH] uml: comment the initialization of a globalJeff Dike
Comment the fact that sig_info is initialized early in boot, and thus doesn't need any locking. 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>
2007-03-06[PATCH] uml: add a debugging messageJeff Dike
Add a debugging message in the case that mapping a stub fails. 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>
2007-03-01[PATCH] uml: host VDSO fixJeff Dike
This fixes a problem seen by a number of people running UML on newer host kernels. init would hang with an infinite segfault loop. It turns out that the host kernel was providing a AT_SYSINFO_EHDR of 0xffffe000, which faked UML into believing that the host VDSO page could be reused. However, AT_SYSINFO pointed into the middle of the address space, and was unmapped as a result. Because UML was providing AT_SYSINFO_EHDR and AT_SYSINFO to its own processes, these would branch to nowhere when trying to use the VDSO. The fix is to also check the location of AT_SYSINFO when deciding whether to use the host's VDSO. 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>
2007-03-01[PATCH] uml: add back accidentally removed errorJeff Dike
In the 2.6.20 hang patch, I accidentally threw out an error message. This puts it back. 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>
2007-02-16[PATCH] uml: fix 2.6.20 hangJeff Dike
A previous cleanup misused need_poll, which had a fairly broken interface. It implemented a growable array, changing the used elements count itself, but leaving it up to the caller to fill in the actual elements, including the entire array if the array had to be reallocated. This worked because the previous users were switching between two such structures, and the elements were copied from the inactive array to the active array after making sure the active array had enough room. maybe_sigio_broken was made to use need_poll, but it was operating on a single array, so when the buffer was reallocated, the previous contents were lost. This patch makes need_poll implement more sane semantics. It merely assures that the array is of the proper size and that the contents are preserved. It is up to the caller to adjust the used elements count and to ensure that the proper elements are resent. This manifested itself as a hang in 2.6.20 as the uninitialized buffer convinced UML that one of its own file descriptors didn't support SIGIO and needed to be watched by poll in a separate thread. The result was an interrupt flood as control traffic over this descriptor sparked interrupts, which resulted in more control traffic, ad nauseum. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] uml: x86_64 thread fixesJeff Dike
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>
2007-02-11[PATCH] uml: fix error output during early bootJeff Dike
The startup code panics a lot if anything goes wrong early on. This is wrong for several reasons, like the kernel isn't running, so you can't really be calling into it yet, but the harm comes from useful error messages being trapped in the printk ring where no one will ever see them. This patch changes these panics to perror and printf in wrappers which also exit. Normal, informational, prints are also wrapped so that fflush(stdout) is called after each one. This is so the output appears in the correct sequence in the event of an error. 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>
2007-02-11[PATCH] uml: AIO locking and tidyingJeff Dike
Comment the lack of locking of data that's set up once at boot time. Also fixed a couple of bogus printks. 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>
2007-02-11[PATCH] uml: register handling formatting fixesJeff Dike
Formatting fixes in the register handling code. 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>
2007-02-11[PATCH] uml: ELF locking commentaryJeff Dike
Comment the lack of locking of the elf data extracted from the ELF headers passed to UML. 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>
2007-02-11[PATCH] uml: umid tidyingJeff Dike
Add an error message when two umids are put on the command line. umid.h is kind of pointless since it only declares one thing, and that is already declared in os.h. Commented the lack of locking of some data in os-Linux/umid.h. 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>
2007-02-11[PATCH] uml: IRQ handler tidyingJeff Dike
Tidying the irq code - make a variable static activate_fd can call kmalloc directly since it's now kernel code added a no-locking comment fixed a style violation 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>
2007-02-11[PATCH] uml: fix style violationsJeff Dike
Fix a bunch of style violations in mem.c. 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>
2007-02-11[PATCH] uml: libc-dependent code should call libc directlyJeff Dike
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>
2007-02-11[PATCH] uml: style fixes in startup codeJeff Dike
Some style fixes in startup.c. 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>
2007-02-11[PATCH] uml: locking comments in startup codeJeff Dike
Add a couple of comments about some non-locked data. 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>
2007-02-11[PATCH] uml: locking comments in memory and tempfile codeJeff Dike
Locking comments and emacs comment removal in the low-level memory and temp file code. 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>