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need this for swapcontext(), KSE upcalls initiated from ast() also need to save them so that we properly return the syscall results after having had a context switch. Note that we don't use r11 in the kernel. However, the runtime specification has defined r8-r11 as return registers, so we put r11 in the context as well. I think deischen@ was trying to tell me that we should save the return registers before. I just wasn't ready for it :-) o The EPC syscall code has 2 return registers and 2 frame markers to save. The first (rp/pfs) belongs to the syscall stub itself. The second (iip/cfm) belongs to the caller of the syscall stub. We want to put the second in the context (note that iip and cfm relate to interrupts. They are only being misused by the syscall code, but are not part of a regular context). This way, when the context is switched to again, we return to the caller of setcontext(2) as one would expect. o Deal with dirty registers on the kernel stack. The getcontext() syscall will flush the RSE, so we don't expect any dirty registers in that case. However, in thread_userret() we also need to save the context in certain cases. When that happens, we are sure that there are dirty registers on the kernel stack. This implementation simply copies the registers, one at a time, from the kernel stack to the user stack. NAT collections are not dealt with. Hence we don't preserve NaT bits. A better solution needs to be found at some later time. We also don't deal with this in all cases in set_mcontext. No temporay solution is implemented because it's not a showstopper. The problem is that we need to ignore the dirty registers and we automaticly do that for at most 62 registers. When there are more than 62 dirty registers we have a memory "leak". This commit is fundamental for KSE support. |
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| bin | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| 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, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. 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, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. 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 sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. 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. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. 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