Projects / User-mode Linux

User-mode Linux

User-Mode Linux lets you run Linux inside Linux. It is a safe, secure way of running Linux versions and Linux processes. Run buggy software, experiment with new Linux kernels or distributions, and poke around in the internals of Linux, all without risking your main Linux setup. User-Mode Linux gives you a virtual machine that may have more hardware and software virtual resources than your actual, physical computer. You can assign your virtual machine only the hardware access you want it to have. With properly limited access, nothing you do on the virtual machine can change or damage your real computer or its software.

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Release Notes: A number of crashes, as well as many other bugs, were fixed. The honeypot procfs filesystem was added. SCSI is now available. Helpers are now killed when UML exits. eth devices inside UML are now guaranteed to get the same names as were specified on the command line. /proc/mconsole was added. uml_moo now sparses its output files, has a destructive merge option, and handles large COW files correctly. There is now a UML jail kit, and the host side of hppfs was added.

Release Notes: It is now possible the to attach the UML gdb to sleeping threads. /proc/exitcode, a hardware watchdog driver, and support for kernel and userspace watchpoints were added. It is now possible to change the backing file of a COW file. The mconsole driver now sends panic notifications to mconsole clients. The crash that some people saw on UML shutdown has been fixed.

Release Notes: UML is now self-hosting. A number of debugging fixes were made, including support for userspace watchpoints, ddd support, allowing the UML debugger to shell out, and closing a security hole. iomem works again. The block driver supports partitioned devices. Many other smaller bugfixes and additions were made. uml_net now acts as a bridge.

Release Notes: Console flow control now works. The consoles and serial lines now support SIGWINCH. The ubd driver's COW bitmaps are now properly byte-swapped. Some drivers now supply entropy to /dev/random. The signal mask is now initialized so that odd environments can't screw UML up by passing in bogus masks. UML is now robust in the face of tmpfs running out of space. Running UML on a processor without cmov support now causes a panic rather than a hang. Crashes caused by use of a tty_struct after it had been freed and by the installation of cmucl have been fixed.

Release Notes: Sound, MTD, LVM, and md are now supported. UML is now secure against a hostile root. The new pthreads library works. Several data corruption bugs were fixed. The console and serial line initializations are now configurable. Persistent TUN/TAP is supported. The BogoMips calculation was fixed. uml_moo now supports V2 COW files. Many other bugs were fixed.


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