- 05 Feb, 2008 40 commits
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Jeff Dike authored
Joe Perches noticed some printks in smp.c that needed fixing. While I was in there, I did the usual tidying in arch/um/kernel, which should be fairly style-clean at this point: copyright updates emacs formatting comments removal include tidying style fixes Cc: Joe Perches <joe@perches.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>
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
Get rid of some syscall counters which haven't been useful in ages. Signed-off-by:
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Jeff Dike authored
A bit of defensive programming - during development, it ocassionally happens that a call to init_new_context is missed, resulting in context holding a host pid of zero. When that address space is torn down, destroy_context does a kill(0), which instantly kills the whole UML without any errors whatsoever. This patch add a check for pids less than 2, to also catch 1 and negative pids. Signed-off-by:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
Customize the hooks in tlb.h to optimize TLB flushing some more. Add start and end fields to tlb_gather_mmu, which are used to limit the address space range scanned when a region is unmapped. The interfaces which just free page tables, without actually changing mappings, don't need to cause a TLB flush. Signed-off-by:
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Jeff Dike authored
Some 64-bit tlb fixes - moved pmd_page_vaddr to pgtable.h since it's the same for both 2-level and 3-level page tables fixed a bogus cast on pud_page_vaddr made the address checking in update_*_range more careful Signed-off-by:
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Jeff Dike authored
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:
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Jeff Dike authored
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: -
Karol Swietlicki authored
Bring back the functionality of stopping user mode linux with the help of mconsole. [jdike - the bug being fixed is that the mconsole file descriptor is already set O_NONBLOCK or not, depending on whether we want no blocking (the normal case) or we want blocking (when an mconsole stop is in effect), so the MSG_DONTWAIT is redundant in the normal case, and wrong when we want to block.] Signed-off-by:
Karol Swietlicki <magotari@gmail.com> Signed-off-by:
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Karol Swietlicki authored
Fix the repetition of the NET symbol. It was once in UML specific options and once in networking. I removed the first occurrence, as it makes more sense to me to keep it only in networking. It also removes a mostly empty file which is not used anymore and some unused variables. Signed-off-by:
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Jeff Dike authored
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:
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Jeff Dike authored
UML still needed some work in order to allow CFLAGS to be passed in from the command line. USER_CFLAGS is produced from KBUILD_CFLAGS in part by removing all the -I switches. This is so that kernel headers don't accidentally get pulled into libc files. However, a common use of command-line CFLAGS would be to add -I switches to the build. This patch specifically adds any command-line -I flags back to USER_CFLAGS. I also corrected the spelling of LFLAGS to LDFLAGS. Signed-off-by:
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Jeff Dike authored
Give the stubs a VMA. This allows the removal of a truly nasty kludge to make sure that mm->nr_ptes was correct in exit_mmap. The underlying problem was always that the stubs, which have ptes, and thus allocated a page table, weren't covered by a VMA. This patch fixes that by using install_special_mapping in arch_dup_mmap and activate_context to create the VMA. The stubs have to be moved, since shift_arg_pages seems to assume that the stack is the only VMA present at that point during exec, and uses vma_adjust to fiddle its VMA. However, that extends the stub VMA by the amount removed from the stack VMA. To avoid this problem, the stubs were moved to a different fixed location at the start of the address space. The init_stub_pte calls were moved from init_new_context to arch_dup_mmap because I was occasionally seeing arch_dup_mmap not being called, causing exit_mmap to die. Rather than figure out what was really happening, I decided it was cleaner to just move the calls so that there's no doubt that both the pte and VMA creation happen, no matter what. arch_exit_mmap is used to clear the stub ptes at exit time. The STUB_* constants in as-layout.h no longer depend on UM_TASK_SIZE, that that definition is removed, along with the comments complaining about gcc. Because the stubs are no longer at the top of the address space, some care is needed while flushing TLBs. update_pte_range checks for addresses in the stub range and skips them. flush_thread now issues two unmaps, one for the range before STUB_START and one for the range after STUB_END. Signed-off-by:
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Jeff Dike authored
Clean up the calculation and use of the usable address space size on the host. task_size is gone, replaced with TASK_SIZE, which is calculated from CONFIG_TOP_ADDR. get_kmem_end and set_task_sizes_skas are also gone. host_task_size, which refers to the entire address space usable by the UML kernel and which may be larger than the address space usable by a UML process, since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR. STACK_TOP is now TASK_SIZE minus the two stub pages. Signed-off-by:
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Joe Perches authored
Add missing space between merged string constants. Signed-off-by:
Joe Perches <joe@perches.com> Signed-off-by:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
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:
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Jeff Dike authored
Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface. It's also made non-static and declared in pgtable.h because it'll be needed when the stubs get a vma. Signed-off-by:
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Jeff Dike authored
Get the sizes of various pieces of data right when using three-level page tables. pgd and pmd entries remain at 32 bits in a 32-bit compilation because page tables will remain in low memory. So, PGDIR_SHIFT, the PTRS_PER_* values, set_pud, set_pmd are conditional on 64BIT. More use of phys_t is made when there are physical memory addresses floating around. ObCheckpatchViolationJustification - the new typedef is an alternate definition of pmd_t, which I can't really live without. Signed-off-by:
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Jeff Dike authored
Tidy current-related stuff. There was a comment in current.h saying that current_thread was obsolete, so this patch turns all instances of current_thread into current_thread_info(). There's some simplifying of the result in arch/um/sys-i386/signal.c. current.h and thread_info also get style cleanups. Signed-off-by:
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Jeff Dike authored
Style fixes in elf-i386.h and arch/um/kernel/mem.c. update the copyright get rid of an emacs formatting comment some formatting fixes inclusion trimming whitespace fixes Signed-off-by: -
Jeff Dike authored
Untangle UML headers somewhat and add some includes where they were needed explicitly, but gotten accidentally via some other header. arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and archsetjmp.h, because it needs jmp_buf. pmd_alloc_one is uninlined because it needs mm_struct, and that's inconvenient to provide in asm-um/pgtable-3level.h. elf_core_copy_fpregs is also uninlined from elf-i386.h and elf-x86_64.h, which duplicated the code anyway, to arch/um/kernel/process.c, so that the reference to current_thread doesn't pull sched.h or anything related into asm/elf.h. arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and arch/um/kernel/skas/uaccess.c got sched.h because they dereference task_structs. Its includes of linux and asm headers got turned from "" to <>. arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno constants. asm/elf-i386 gets asm/user.h because it needs user_regs_struct. asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and system.h for BUG_ON. asm/pgtable doesn't need sched.h. asm/processor-generic.h defined mm_segment_t, but didn't use it. So, that definition is moved to uaccess.h, which defines a bunch of mm_segment_t-related stuff. thread_info.h uses mm_segment_t, and includes uaccess.h, which causes a recursion. So, the definition is placed above the include of thread_info. in uaccess.h. thread_info.h also gets page.h because it needs PAGE_SIZE. ObCheckpatchViolationJustification - I'm not adding a typedef; I'm moving mm_segment_t from one place to another. Signed-off-by:
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Jeff Dike authored
This patchset makes UML build and run with three-level page tables on 32-bit hosts. This is an uncommon use case, but the code here needed fixing and cleaning up, so 32-bit three-level pages tables were tested to make sure the changes are good. Patch 1 - code movement Patch 2 - header untangling Patch 3 - style fixups in files affected so far Patch 4 - clean up use of current.h Patch 5 - fix sizes of types that are different between 2 and 3-level page tables - three-level page table support should build at this point Patch 6 - tidy (i.e. eliminate much of) the code that figures out how big the address space is Patch 7 - change um_virt_to_phys into virt_to_pte, clean its interface, and clean its (so far) one caller Patch 8 - the stub pages are covered with a VMA, allowing some nasty code to be thrown out - three-level page tables now work This patch: um_virt_to_phys only has one user, so it can be moved to the same file and made static. Its declarations in pgtable.h and ksyms.c are also gone. current_cmd was another apparent user, but it itself isn't used, so it is deleted. Signed-off-by:
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Jeff Dike authored
Add some diagnostics when TLS operations on the host fail. Also spit out more information about the TLS environment on the host at boot time. Signed-off-by:
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Karol Swietlicki authored
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:
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Karol Swietlicki authored
This patch removes a variable which was not used in two functions. Yet another code cleanup, nothing really significant. Please note that I could not test this on x86_64. I don't have the hardware for it. [ jdike - Bits of tidying around the affected code. Also, it's fine on x86_64 ] Signed-off-by:
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Lucas Woods authored
Signed-off-by:
Lucas Woods <woodzy@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by:
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Jeff Dike authored
The previous const-ing patch consted a string which shouldn't have been, and I didn't notice the gcc warning. ubd_setup can't take a const char * because its address is assigned to something which expects a char *arg. Many setups modify the string they are given, they can't be const. Signed-off-by:
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Jeff Dike authored
The earlier pgtable.h tidying patch made things a bit too tidy. Add back a header which is needed in VMALLOC_START and friend. Also add back a definition of pmd_page_vaddr, which is needed on x86_64. Signed-off-by:
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Jeff Dike authored
Large pieces of include/asm/pgtable.h were unused cruft. This uncovered arch/um/kernel/trap.c needing skas.h in order to get ptrace_faultinfo. Signed-off-by:
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Jeff Dike authored
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:
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Jeff Dike authored
Allow LFLAGS to be given to make and have the expected effect. Signed-off-by:
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Jeff Dike authored
Robert Day noticed a few unused headers in UML, so this gets rid of them. Cc: "Robert P. J. Day" <rpjday@crashcourse.ca> Signed-off-by:
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