freebsd kernel with SKQ
a95582c6fd
Keyboard input needs Giant locking, and that is not possible to do correctly here. Use mtx_trylock() and proceed unlocked as before if we can't acquire Giant (non-recursively), except in kdb mode don't even try to acquire Giant. Everything here is a hack, but it often works. Even if mtx_trylock() succeeds, this might be a LOR. Keyboard input also needs screen locking, to handle screen updates and switches. Add this, using the same simplistic screen locking as for sc_cnputc(). Giant must be acquired before the screen lock, and the screen lock must be dropped when calling the keyboard driver (else it would get a harmless LOR if it tries to acquire Giant). It was intended that sc cn open/close hide the locking calls, and they do for i/o functions functions except for this complication. Non-console keyboard input is still only Giant-locked, with screen locking in some called functions. This is correct for the keyboard parts only. When Giant cannot be acquired properly, atkbd and kbdmux tend to race and work (they assume that the caller acquired Giant properly and don't try to acquire it again or check that it has been acquired, and the races rarely matter), while ukbd tends to deadlock or panic (since it does the opposite, and has other usb threads to deadlock with). The keyboard (Giant) locking here does very little, but the screen locking completes screen locking for console mode except for not detecting or handling deadlock. |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7) and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The `buildkernel` and `installkernel` targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process. See build(7), config(8), and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information. Note: If you want to build and install the kernel with the `buildkernel` and `installkernel` targets, you might need to build world before. More information is available in the handbook. The kernel configuration files reside in the sys/<arch>/conf sub-directory. GENERIC is the default configuration used in release builds. NOTES contains entries and documentation for all possible devices, not just those commonly used. Source Roadmap: --------------- bin System/user commands. cddl Various commands and libraries under the Common Development and Distribution License. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tests Regression tests which can be run by Kyua. See tests/README for additional information. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html