#
6d64095e |
|
09-Nov-2023 |
Benjamin Berg <benjamin@sipsolutions.net> |
um: Do not use printk in userspace trampoline The trampoline is running in a cloned process. It is not safe to use printk for error printing there. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
57135337 |
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09-Nov-2023 |
Benjamin Berg <benjamin@sipsolutions.net> |
um: Drop NULL check from start_userspace start_userspace is only called from exactly one location, and the passed pointer for the userspace process stack cannot be NULL. Remove the check, without changing the control flow. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
a5571984 |
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09-Nov-2023 |
Benjamin Berg <benjamin@sipsolutions.net> |
um: Drop support for hosts without SYSEMU_SINGLESTEP support These features have existed since Linux 2.6.14 and can be considered widely available at this point. Also drop the backward compatibility code for PTRACE_SETOPTIONS. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> ---- v2: * Continue to define PTRACE_SYSEMU_SINGLESTEP as glibc only added it in version 2.27. Signed-off-by: Richard Weinberger <richard@nod.at>
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#
6032aca0 |
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14-Apr-2023 |
Johannes Berg <johannes.berg@intel.com> |
um: make stub data pages size tweakable There's a lot of code here that hard-codes that the data is a single page, and right now that seems to be sufficient, but to make it easier to change this in the future, add a new STUB_DATA_PAGES constant and use it throughout the code. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
d119595f |
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22-Nov-2022 |
Benjamin Berg <benjamin@sipsolutions.net> |
um: Switch printk calls to adhere to correct coding style This means having the string literal in one line and using __func__ where appropriate. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
8970d5c9 |
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14-Jul-2022 |
Guenter Roeck <linux@roeck-us.net> |
um: Replace to_phys() and to_virt() with less generic function names to_virt() and to_phys() are very generic and may be defined by drivers. As it turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()") did exactly that. This results in build errors such as the following when trying to build um:allmodconfig. drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’: ./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’ 105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt)) | ^~~~~~~ Use less generic function names for the um specific to_phys() and to_virt() functions to fix the problem and to avoid similar problems in the future. Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()") Cc: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
dda520d0 |
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13-Jul-2022 |
Jason A. Donenfeld <Jason@zx2c4.com> |
um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups QEMU has a -no-reboot option, which halts instead of reboots when the guest asks to reboot. This is invaluable when used with CONFIG_PANIC_TIMEOUT=-1 (and panic_on_warn), because it allows panics and warnings to be caught immediately in CI. Implement this in UML too, by way of a basic setup param. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
097da1a4 |
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14-Jul-2022 |
Guenter Roeck <linux@roeck-us.net> |
um: Replace to_phys() and to_virt() with less generic function names The UML function names to_virt() and to_phys() are exposed by UML headers, and are very generic and may be defined by drivers. As it turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()") did exactly that. This results in build errors such as the following when trying to build um:allmodconfig: drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’: ./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’ 105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt)) | ^~~~~~~ Use less generic function names for the um specific to_phys() and to_virt() functions to fix the problem and to avoid similar problems in the future. Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()") Cc: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
558f9b2f |
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19-Apr-2021 |
YiFei Zhu <zhuyifei1999@gmail.com> |
um: Fix stack pointer alignment GCC assumes that stack is aligned to 16-byte on call sites [1]. Since GCC 8, GCC began using 16-byte aligned SSE instructions to implement assignments to structs on stack. When CC_OPTIMIZE_FOR_PERFORMANCE is enabled, this affects os-Linux/sigio.c, write_sigio_thread: struct pollfds *fds, tmp; tmp = current_poll; Note that struct pollfds is exactly 16 bytes in size. GCC 8+ generates assembly similar to: movdqa (%rdi),%xmm0 movaps %xmm0,-0x50(%rbp) This is an issue, because movaps will #GP if -0x50(%rbp) is not aligned to 16 bytes [2], and how rbp gets assigned to is via glibc clone thread_start, then function prologue, going though execution trace similar to (showing only relevant instructions): sub $0x10,%rsi mov %rcx,0x8(%rsi) mov %rdi,(%rsi) syscall pop %rax pop %rdi callq *%rax push %rbp mov %rsp,%rbp The stack pointer always points to the topmost element on stack, rather then the space right above the topmost. On push, the pointer decrements first before writing to the memory pointed to by it. Therefore, there is no need to have the stack pointer pointer always point to valid memory unless the stack is poped; so the `- sizeof(void *)` in the code is unnecessary. On the other hand, glibc reserves the 16 bytes it needs on stack and pops itself, so by the call instruction the stack pointer is exactly the caller-supplied sp. It then push the 16 bytes of the return address and the saved stack pointer, so the base pointer will be 16-byte aligned if and only if the caller supplied sp is 16-byte aligned. Therefore, the caller must supply a 16-byte aligned pointer, which `stack + UM_KERN_PAGE_SIZE` already satisfies. On a side note, musl is unaffected by this issue because it forces 16 byte alignment via `and $-16,%rsi` in its clone wrapper. Similarly, glibc i386 is also unaffected because it has `andl $0xfffffff0, %ecx`. To reproduce this bug, enable CONFIG_UML_RTC and CC_OPTIMIZE_FOR_PERFORMANCE. uml_rtc will call add_sigio_fd which will then cause write_sigio_thread to either go into segfault loop or panic with "Segfault with no mm". Similarly, signal stacks will be aligned by the host kernel upon signal delivery. `- sizeof(void *)` to sigaltstack is unconventional and extraneous. On a related note, initialization of longjmp buffers do require `- sizeof(void *)`. This is to account for the return address that would have been pushed to the stack at the call site. The reason for uml to respect 16-byte alignment, rather than telling GCC to assume 8-byte alignment like the host kernel since commit d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported"), is because uml links against libc. There is no reason to assume libc is also compiled with that flag and assumes 8-byte alignment rather than 16-byte. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838 [2] https://c9x.me/x86/html/file_module_x86_id_180.html Signed-off-by: YiFei Zhu <zhuyifei1999@gmail.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
bfc58e2b |
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13-Jan-2021 |
Johannes Berg <johannes.berg@intel.com> |
um: remove process stub VMA This mostly reverts the old commit 3963333fe676 ("uml: cover stubs with a VMA") which had added a VMA to the existing PTEs. However, there's no real reason to have the PTEs in the first place and the VMA cannot be 'fixed' in place, which leads to bugs that userspace could try to unmap them and be forcefully killed, or such. Also, there's a bit of an ugly hole in userspace's address space. Simplify all this: just install the stub code/page at the top of the (inner) address space, i.e. put it just above TASK_SIZE. The pages are simply hard-coded to be mapped in the userspace process we use to implement an mm context, and they're out of reach of the inner mmap/munmap/mprotect etc. since they're above TASK_SIZE. Getting rid of the VMA also makes vma_merge() no longer hit one of the VM_WARN_ON()s there because we installed a VMA while the code assumes the stack VMA is the first one. It also removes a lockdep warning about mmap_sem usage since we no longer have uml_setup_stubs() and thus no longer need to do any manipulation that would require mmap_sem in activate_mm(). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
84b2789d |
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13-Jan-2021 |
Johannes Berg <johannes.berg@intel.com> |
um: separate child and parent errors in clone stub If the two are mixed up, then it looks as though the parent returned an error if the child failed (before) the mmap(), and then the resulting process never gets killed. Fix this by splitting the child and parent errors, reporting and using them appropriately. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
a7d48886 |
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13-Jan-2021 |
Johannes Berg <johannes.berg@intel.com> |
um: defer killing userspace on page table update failures In some cases we can get to fix_range_common() with mmap_sem held, and in others we get there without it being held. For example, we get there with it held from sys_mprotect(), and without it held from fork_handler(). Avoid any issues in this and simply defer killing the task until it runs the next time. Do it on the mm so that another task that shares the same mm can't continue running afterwards. Cc: stable@vger.kernel.org Fixes: 468f65976a8d ("um: Fix hung task in fix_range_common()") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
e1e22d0d |
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13-Jan-2021 |
Johannes Berg <johannes.berg@intel.com> |
um: print register names in wait_for_stub Since we're basically debugging the userspace (it runs in ptrace) it's useful to dump out the registers - but they're not readable, so if something goes wrong it's hard to say what. Print the names of registers in the register dump so it's easier to look at. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
3c6ac61b |
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10-Nov-2020 |
Anton Ivanov <anton.ivanov@cambridgegreys.com> |
um: Fetch registers only for signals which need them UML userspace fetches siginfo and passes it to signal handlers in UML. This is needed only for some of the signals, because key handlers like SIGIO make no use of this variable. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
97870c34 |
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25-Aug-2019 |
Alex Dewar <alex.dewar@gmx.co.uk> |
um: Add SPDX headers for files in arch/um/os-Linux Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
0dafcbe1 |
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23-Aug-2019 |
Johannes Berg <johannes.berg@intel.com> |
um: Implement TRACE_IRQFLAGS_SUPPORT UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement it. It seems to have been added for lockdep support, but that can't actually really work well without IRQ flags tracing, as is also very noisily reported when enabling CONFIG_DEBUG_LOCKDEP. Implement it now. Fixes: 711553efa5b8 ("[PATCH] uml: declare in Kconfig our partial LOCKDEP support") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
7ff1e34b |
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15-Jun-2018 |
Richard Weinberger <richard@nod.at> |
um: Give start_idle_thread() a return code Fixes: arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of non-void function [-Wreturn-type] longjmp() never returns but gcc still warns that the end of the function can be reached. Add a return code and debug aid to detect this impossible case. Signed-off-by: Richard Weinberger <richard@nod.at>
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#
6f602afd |
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29-Jul-2017 |
Thomas Meyer <thomas@m3y3r.de> |
um: Fix FP register size for XSTATE/XSAVE Hard code max size. Taken from https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdb/common/x86-xstate.h Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
e9099830 |
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05-Jul-2017 |
Thomas Meyer <thomas@m3y3r.de> |
um: Add kerneldoc for userspace_tramp() and start_userspace() Also use correct function name spelling (stub_segv_handler) for better grepping Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
22e19c8d |
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05-Jul-2017 |
Thomas Meyer <thomas@m3y3r.de> |
um: userspace - be more verbose in ptrace set regs error When ptrace fails to set GP/FP regs for the target process, log the error before crashing the UML kernel. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
ce458606 |
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04-May-2017 |
Richard Weinberger <richard@nod.at> |
um: Add missing NR_CPUS include We need linux/threads.h for that variable. Fixes: 8bba077066d6d0 ("um: Set number of CPUs") Signed-off-by: Richard Weinberger <richard@nod.at>
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#
8bba0770 |
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02-Mar-2017 |
Nikola Kotur <kotnick@gmail.com> |
um: Set number of CPUs Define NR_CPUS required by the timer subsystem. Fixes this make warning: scripts/kconfig/conf --oldconfig arch/x86/um/Kconfig kernel/time/Kconfig:155:warning: range is invalid Signed-off-by: Nikola Kotur <kotnick@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
e04c989e |
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29-Dec-2015 |
Mickaël Salaün <mic@digikod.net> |
um: Fix ptrace GETREGS/SETREGS bugs This fix two related bugs: * PTRACE_GETREGS doesn't get the right orig_ax (syscall) value * PTRACE_SETREGS can't set the orig_ax value (erased by initial value) Get rid of the now useless and error-prone get_syscall(). Fix inconsistent behavior in the ptrace implementation for i386 when updating orig_eax automatically update the syscall number as well. This is now updated in handle_syscall(). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Anton Ivanov <aivanov@brocade.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: David Drysdale <drysdale@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Kees Cook <keescook@chromium.org>
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#
2eb5f31b |
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02-Nov-2015 |
Anton Ivanov <aivanov@brocade.com> |
um: Switch clocksource to hrtimers UML is using an obsolete itimer call for all timers and "polls" for kernel space timer firing in its userspace portion resulting in a long list of bugs and incorrect behaviour(s). It also uses ITIMER_VIRTUAL for its timer which results in the timer being dependent on it running and the cpu load. This patch fixes this by moving to posix high resolution timers firing off CLOCK_MONOTONIC and relaying the timer correctly to the UML userspace. Fixes: - crashes when hosts suspends/resumes - broken userspace timers - effecive ~40Hz instead of what they should be. Note - this modifies skas behavior by no longer setting an itimer per clone(). Timer events are relayed instead. - kernel network packet scheduling disciplines - tcp behaviour especially under load - various timer related corner cases Finally, overall responsiveness of userspace is better. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Anton Ivanov <aivanov@brocade.com> [rw: massaged commit message] Signed-off-by: Richard Weinberger <richard@nod.at>
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#
1d80f0cd |
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25-Oct-2015 |
Richard Weinberger <richard@nod.at> |
um: Store syscall number after syscall_trace_enter() To support changing syscall numbers we have to store it after syscall_trace_enter(). Signed-off-by: Richard Weinberger <richard@nod.at>
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#
5f32943b |
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12-Oct-2014 |
Nicolas Iooss <nicolas.iooss_linux@m4x.org> |
um/os-Linux: Use char[] for syscall_stub declarations When declaring __syscall_stub_start, use the same type in UML userspace code as in arch/um/include/asm/sections.h. While at it, also declare batch_syscall_stub as char[]. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
33bbc306 |
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28-Mar-2015 |
Thomas Meyer <thomas@m3y3r.de> |
um: Move uml_postsetup in the init_thread stack atomic_notifier_chain_register() and uml_postsetup() do call kernel code that rely on the "current" kernel macro and a valid task_struct resp. thread_info struct. Give those functions a valid stack by moving uml_postsetup() in the init_thread stack. This moves enables a panic() call in this early code to generate a valid stacktrace, instead of crashing. E.g. when an UML kernel is started with an initrd but too few physical memory the panic() call get's actually processed. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
d0b5e15f |
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18-Mar-2015 |
Richard Weinberger <richard@nod.at> |
um: Remove SKAS3/4 support Before we had SKAS0 UML had two modes of operation TT (tracing thread) and SKAS3/4 (separated kernel address space). TT was known to be insecure and got removed a long time ago. SKAS3/4 required a few (3 or 4) patches on the host side which never went mainline. The last host patch is 10 years old. With SKAS0 mode (separated kernel address space using 0 host patches), default since 2005, SKAS3/4 is obsolete and can be removed. Signed-off-by: Richard Weinberger <richard@nod.at>
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#
ae5db6d1 |
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19-Jul-2014 |
Richard Weinberger <richard@nod.at> |
Revert "um: Fix wait_stub_done() error handling" This reverts commit 0974a9cadc7886f7baaa458bb0c89f5c5f9d458e. The real for for that issue is to release current->mm->mmap_sem in fix_range_common(). Signed-off-by: Richard Weinberger <richard@nod.at>
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#
9a8c1359 |
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19-Jul-2013 |
Richard Weinberger <richard@nod.at> |
um: siginfo cleanup Currently we use both struct siginfo and siginfo_t. Let's use struct siginfo internally to avoid ongoing compiler warning. We are allowed to do so because struct siginfo and siginfo_t are equivalent. Signed-off-by: Richard Weinberger <richard@nod.at>
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#
0974a9ca |
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17-May-2013 |
Richard Weinberger <richard@nod.at> |
um: Fix wait_stub_done() error handling If we die within a stub handler we only way to reliable kill the (obviously) dying uml guest process is killing it's host twin on the host side. Signed-off-by: Richard Weinberger <richard@nod.at>
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#
37185b33 |
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07-Oct-2012 |
Al Viro <viro@ZenIV.linux.org.uk> |
um: get rid of pointless include "..." where include <...> will do Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
d3c1cfcd |
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01-Aug-2012 |
Martin Pärtel <martin.partel@gmail.com> |
um: pass siginfo to guest process UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE, SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct where previously they were si_addr = NULL and si_code = 128. Signed-off-by: Martin Pärtel <martin.partel@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
b8a42095 |
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22-May-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
um: pull interrupt_end() into userspace() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
966e803a |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: unify ptrace_user.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
510c72a3 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: take chan_*.h and line.h to arch/um/drivers Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
17e05209 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: take register_winch_irq() into the caller of is_skas_winch() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
0de021f7 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: shared/process.h is empty now; kill it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
00361683 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: fill the handlers array at build time Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
e87df986 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: simplify set_handler() For one thing, we always block the same signals (IRQ ones - IO, WINCH, VTALRM), so there's no need to pass sa_mask elements in arguments. For another, the flags depend only on whether it's an IRQ signal or not (we add SA_RESTART for them). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
d5c7e8b4 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: don't bother blocking SIGARLM and SIGUSR1 We used to generate those, but we hadn't done that for a long time. No need to bother blocking them for signal handlers. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
9b25fcbd |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: switch stub_segv_handler to SA_SIGINFO variant, get rid of magic crap in there Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
078073a3 |
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18-Aug-2011 |
Al Viro <viro@ftp.linux.org.uk> |
um: -include user.h for USER_OBJ, trim includes Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
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#
fbfe9c84 |
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14-Sep-2011 |
Ingo van Lil <inguin@gmx.de> |
um: Save FPU registers between task switches Some time ago Jeff prepared 42daba316557 ("uml: stop saving process FP state") for UML to stop saving the process FP state between task switches. The assumption was that since with SKAS0 every guest process runs inside a host process context the host OS will take care of keeping the proper FP state. Unfortunately this is not true for multi-threaded applications, where all guest threads share a single host process context yet all may use the FPU on their own. Although I haven't verified it I suspect things to be even worse in SKAS3 mode where all guest processes run inside a single host process. The patch reintroduces the saving and restoring of the FP context between task switches. [richard@nod.at: Ingo posted this patch in 2009, sadly it was never applied and got lost. Now in 2011 the problem was reported by Gunnar.] Signed-off-by: Ingo van Lil <inguin@gmx.de> Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: <gunnarlindroth@hotmail.com> Tested-by: <gunnarlindroth@hotmail.com> Cc: Stanislav Meduna <stano@meduna.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
99764fa4 |
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23-Jul-2008 |
WANG Cong <xiyou.wangcong@gmail.com> |
UML: make several more things static - Make some variables and functions static, since they don't need to be global. - Remove an unused function - arch/um/kernel/time.c::sched_clock(). - Clean the style a bit as complained by checkpatch.pl. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3d5ede6f |
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05-Jun-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: stub needs to tolerate SIGWINCH We lost the marking of SIGWINCH as being OK to receive during stub execution, causing a panic should that happen. Cc: Benedict Verheyen <benedict.verheyen@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>
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#
96cee304 |
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12-May-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: style fixes A few random style fixes. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
2f56debd |
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23-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: fix FP register corruption Commit ee3d9bd4de1ed93d2a7ee41c331ed30a1c7b8acd ("uml: simplify SIGSEGV handling"), while greatly simplifying the kernel SIGSEGV handler that runs in the process address space, introduced a bug which corrupts FP state in the process. Previously, the SIGSEGV handler called the sigreturn system call by hand - it couldn't return through the restorer provided to it because that could try to call the libc restorer which likely wouldn't exist in the process address space. So, it blocked off some signals, including SIGUSR1, on entry to the SIGSEGV handler, queued a SIGUSR1 to itself, and invoked sigreturn. The SIGUSR1 was delivered, and was visible to the UML kernel after sigreturn finished. The commit eliminated the signal masking and the call to sigreturn. The handler simply hits itself with a SIGTRAP to let the UML kernel know that it is finished. UML then restores the process registers, which effectively longjmps the process out of the signal handler, skipping sigreturn's restoring of register state and the signal mask. The bug is that the host apparently sets used_fp to 0 when it saves the process FP state in the sigcontext on the process signal stack. Thus, when the process is longjmped out of the handler, its FP state is corrupt because it wasn't saved on the context switch to the UML kernel. This manifested itself as sleep hanging. For some reason, sleep uses floating point in order to calculate the sleep interval. When a page fault corrupts its FP state, it is faked into essentially sleeping forever. This patch saves the FP state before entering the SIGSEGV handler and restores it afterwards. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
5134d8fe |
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08-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: style fixes in arch/um/os-Linux Style changes under arch/um/os-Linux: include trimming CodingStyle fixes some printks needed severity indicators make_tempfile turns out not to be used outside of mem.c, so it is now static. Its declaration in tempfile.h is no longer needed, and tempfile.h itself is no longer needed. create_tmp_file was also made static. checkpatch moans about an EXPORT_SYMBOL in user_syms.c which is part of a macro definition - this is copying a bit of kernel infrastructure into the libc side of UML because the kernel headers can't be included there. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b5498832 |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: add newlines to printks Some printks were missing newlines. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
e06173bd |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: don't allow processes to call into stub Kill a process that tries to branch into a stub and execute a system call. There are no security implications here - a system call in a stub is treated the same as a system call anywhere else. But if a process is trying to branch into a stub, either it is trying something nasty or it has gone haywire, so it's a good idea to get rid of it in either case. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3e6f2ac4 |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: kill processes instead of panicing kernel 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>
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#
d25f2e12 |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: use ptrace directly in libc code Some register accessor cleanups - userspace() was calling restore_registers and save_registers for no reason, since userspace() is on the libc side of the house, and these add no value over calling ptrace directly init_thread_registers and get_safe_registers were the same thing, so init_thread_registers is gone Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
ee3d9bd4 |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: simplify SIGSEGV handling Simplify the page fault stub by not masking signals while it is running. This allows it to signal that it is done by executing an instruction which will generate a SIGTRAP (int3 on x86) rather than running sigreturn by hand after queueing a blocked SIGUSR1. userspace_tramp now no longer puts anything in the SIGSEGV sa_mask, but it does add SA_NODEFER to sa_flags so that SIGSEGV is still enabled after the signal handler fails to run sigreturn. SIGWINCH is just blocked so that we don't have to deal with it and the signal masks used by wait_stub_done are updated to reflect the smaller number of signals that it has to worry about. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
edea1385 |
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04-Feb-2008 |
Jeff Dike <jdike@addtoit.com> |
uml: tidy kern_util.h 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>
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#
4dbed85a |
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17-Dec-2007 |
Stanislaw Gruszka <stf_xl@wp.pl> |
uml: stop gdb from deleting breakpoints when running UML 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>
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#
a24864a1 |
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16-Oct-2007 |
Lepton Wu <ytht.net@gmail.com> |
uml: definitively kill subprocesses on panic In a stock 2.6.22.6 kernel, poweroff a user mode linux guest (2.6.22.6 running in skas0 mode) will halt the host linux. I think the reason is the kernel thread abort because of a bug. Then the sys_reboot in process of user mode linux guest is not trapped by the user mode linux kernel and is executed by host. I think it is better to make sure all of our children process to quit when user mode linux kernel abort. [ jdike - the kernel process needs to ignore SIGTERM, plus the waitpid/kill loop is needed to make sure that all of our children are dead before the kernel exits ] Signed-off-by: Lepton Wu <ytht.net@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
54ae36f2 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: fix stub address calculations The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the cold. I'd rather not duplicate the four known host vmsplit cases for each of these symbols. I'd also like to calculate them based on the highest userspace address. The Kconfig language seems not to allow calculation of hex constants, so I moved this to as-layout.h. CONFIG_STUB_CODE, CONFIG_STUB_DATA, and CONFIG_STUB_START are now gone. In their place are STUB_CODE, STUB_DATA, and STUB_START in as-layout.h. i386 and x86_64 seem to differ as to whether an unadorned constant is an int or a long, so I cast them to unsigned long so they can be printed consistently. However, they are also used in stub.S, where C types don't work so well. So, there are ASM_ versions of these constants for use in stub.S. I also ifdef-ed the non-asm-friendly portion of as-layout.h. With this in place, most of the rest of this patch is changing CONFIG_STUB_* to STUB_*, except in stub.S, where they are changed to ASM_STUB_*. defconfig has the old symbols deleted. I also print these addresses out in case there is any problem mapping them on the host. The two stub.S files had some trailing whitespace, so that is cleaned up here. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
1a805219 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: use *SEC_PER_*SEC constants 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>
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#
61b63c55 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: eliminate SIGALRM Now that ITIMER_REAL is no longer used, there is no need for any use of SIGALRM whatsoever. This patch removes all mention of it. In addition, real_alarm_handler took a signal argument which is now always SIGVTALRM. So, that is gone. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
d2753a6d |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: tickless support 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>
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#
a2f018bf |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: simplify interval setting 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>
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#
532d0fa4 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: eliminate hz() Eliminate hz() since its only purpose was to provide a kernel-space constant to userspace code. This can be done instead by providing the constant directly through kernel_constants.h. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
512b6fb1 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: userspace files should call libc directly 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>
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#
18baddda |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: rename pt_regs general-purpose register file Before the removal of tt mode, access to a register on the skas-mode side of a pt_regs struct looked like pt_regs.regs.skas.regs.regs[FOO]. This was bad enough, but it became pt_regs.regs.regs.regs[FOO] with the removal of the union from the middle. To get rid of the run of three "regs", the last field is renamed to "gp". 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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#
0a7675aa |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: remove __u64 usage from physical memory subsystem Eliminate some uses of __u64 in the physical memory support. It's hard to get a definition of __u64 in both kernel and userspace code on x86_64, so this changes them to unsigned long long. There are also a copyright update and formatting comment removal from the affected header. 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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#
ba180fd4 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: style fixes pass 3 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>
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#
77bf4400 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: remove code made redundant by CHOOSE_MODE removal 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>
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#
42daba31 |
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16-Oct-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: stop saving process FP state 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>
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#
42a359e3 |
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16-Jul-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: SIGIO support cleanup Cleanup of the SIGWINCH support. Some code and comment reformatting. The stack used for SIGWINCH threads was leaked. This is now fixed by storing it with the pid and other information, and freeing it when the thread is killed. If something goes wrong with a WIGWINCH thread, and this is discovered in the interrupt handler, the winch record would leak. It is now freed, except that the IRQ isn't freed. This is hard to do from interrupt context. This has the side-effect that the IRQ system maintains a reference to the freed structure, but that shouldn't cause a problem since the descriptor is disabled. register_winch_irq is now much better about cleaning up after an initialization failure. 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>
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#
c539ab73 |
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16-Jun-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: remove PAGE_SIZE from libc code Distros seem to be removing PAGE_SIZE from asm/page.h. So, the libc side of UML should stop using it. I replace it with UM_KERN_PAGE_SIZE, which is defined to be the same as PAGE_SIZE on the kernel side of the house. I could also use getpagesize(), but it's more important that UML have the same value of PAGE_SIZE everywhere. It's conceivable that it could be built with a larger PAGE_SIZE, and use of getpagesize() would break that badly. PAGE_MASK got the same treatment, as it is closely tied to PAGE_SIZE. 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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#
2ea5bc5e |
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10-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: tidy IRQ code 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>
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#
e1a79c40 |
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10-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: use UM_THREAD_SIZE in userspace code 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>
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#
0e7d18b5 |
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09-May-2007 |
Miklos Szeredi <mszeredi@suse.cz> |
uml: turn build warnings into comments 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>
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#
16dd07bc |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: more page fault path trimming 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>
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#
77f6af77 |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: don't try to handle signals on initial process stack 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>
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a61f334f |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: convert libc layer to call read and write 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>
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ef0470c0 |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: tidy libc code 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>
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f30c2c98 |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: dump registers on ptrace or wait failure 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>
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1ffb9164 |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: remove page_size() 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>
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9218b171 |
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06-May-2007 |
Jeff Dike <jdike@addtoit.com> |
uml: remove user_util.h 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>
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b92c4f92 |
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26-Mar-2007 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: use correct register file size everywhere 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>
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b4cf95c6 |
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06-Mar-2007 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: add a debugging message 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>
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1f6f6164 |
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02-Nov-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: include tidying In order to get the __NR_* constants, we need sys/syscall.h. linux/unistd.h works as well since it includes syscall.h, however syscall.h is more parsimonious. We were inconsistent in this, and this patch adds syscall.h includes where necessary and removes linux/unistd.h includes where they are not needed. asm/unistd.h also includes the __NR_* constants, but these are not the glibc-sanctioned ones, so this also removes one such inclusion. 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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3c917350 |
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27-Sep-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: thread creation tidying 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>
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537ae946 |
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26-Sep-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: timer cleanups 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>
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4b84c69b |
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26-Sep-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: Move signal handlers to arch code Have most signals go through an arch-provided handler which recovers the sigcontext and then calls a generic handler. This replaces the ARCH_GET_SIGCONTEXT macro, which was somewhat fragile. On x86_64, recovering %rdx (which holds the sigcontext pointer) must be the first thing that happens. sig_handler duly invokes that first, but there is no guarantee that I can see that instructions won't be reordered such that %rdx is used before that. Having the arch provide the handler seems much more robust. Some signals in some parts of UML require their own handlers - these places don't call set_handler any more. They call sigaction or signal themselves. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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13c06be3 |
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26-Sep-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: Use klibc setjmp/longjmp This patch adds an implementation of setjmp and longjmp to UML, allowing access to the inside of a jmpbuf without needing the access macros formerly provided by libc. The implementation is stolen from klibc. I copy the relevant files into arch/um. I have another patch which avoids the copying, but requires klibc be in the tree. setjmp and longjmp users required some tweaking. Includes of <setjmp.h> were removed and includes of the UML longjmp.h were added where necessary. There are also replacements of siglongjmp with UML_LONGJMP which I somehow missed earlier. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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a5df0d1a |
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14-Jul-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: tidy longjmp macro The UML_SETJMP macro was requiring its users to pass in a argument which it could supply itself, since it wasn't used outside that invocation of the macro. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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e64bd134 |
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10-Jul-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: signal initialization cleanup It turns out that init_new_thread_signals is always called with altstack == 1, so we can eliminate the parameter. 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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2ace87b9 |
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01-May-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: error handling fixes Blairsorblade noticed some confusion between our use of a system call's return value and errno. This patch fixes a number of related bugs - using errno instead of a return value using a return value instead of errno forgetting to negate a error return to get a positive error code 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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ad28e029 |
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18-Apr-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: change sigjmp_buf to jmp_buf Clean up the jmpbuf code. Since softints, we no longer use sig_setjmp, so the UML_SIGSETJMP wrapper now has a misleading name. Also, I forgot to change the buffers from sigjmp_buf to jmp_buf. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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802e3077 |
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10-Apr-2006 |
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> |
[PATCH] uml: fix format errors Now that GCC warns about format errors, fix them. Nothing able to cause a crash, however. 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>
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e2216feb |
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07-Feb-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: initialize process FP registers properly We weren't making sure that we initialized the FP registers of new processes to sane values. This patch also moves some defines in the affected area closer to where they are used. 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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1d7173ba |
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18-Jan-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: implement soft interrupts This patch implements soft interrupts. Interrupt enabling and disabling no longer map to sigprocmask. Rather, a flag is set indicating whether interrupts may be handled. If a signal comes in and interrupts are marked as OK, then it is handled normally. If interrupts are marked as off, then the signal handler simply returns after noting that a signal needs handling. When interrupts are enabled later on, this pending signals flag is checked, and the IRQ handlers are called at that point. The point of this is to reduce the cost of local_irq_save et al, since they are very much more common than the signals that they are enabling and disabling. Soft interrupts produce a speed-up of ~25% on a kernel build. Subtleties - UML uses sigsetjmp/siglongjmp to switch contexts. sigsetjmp has been wrapped in a save_flags-like macro which remembers the interrupt state at setjmp time, and restores it when it is longjmp-ed back to. The enable_signals function has to loop because the IRQ handler disables interrupts before returning. enable_signals has to return with signals enabled, and signals may come in between the disabling and the return to enable_signals. So, it loops for as long as there are pending signals, ensuring that signals are enabled when it finally returns, and that there are no pending signals that need to be dealt with. 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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09ee011e |
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18-Jan-2006 |
Jeff Dike <jdike@addtoit.com> |
[PATCH] uml: eliminate some globals Stop using global variables to hold the file descriptor and offset used to map the skas0 stubs. Instead, calculate them using the page physical addresses. 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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abaf6977 |
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18-Jan-2006 |
Gennady Sharapov <Gennady.V.Sharapov@intel.com> |
[PATCH] uml: move libc-dependent skas process handling The serial UML OS-abstraction layer patch (um/kernel/skas dir). This moves all systemcalls from skas/process.c file under os-Linux dir and join skas/process.c and skas/process_kern.c files. Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com> 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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