freebsd with flexible iflib nic queues
ac8c7680a6
use set_mcontext() to restore the context in sigreturn(). Since we put the syscall number and the syscall arguments in the trapframe (we don't save the scratch registers for syscalls, which allows us to reuse the space to our advantage), create a MD specific flag so that we save the scratch registers even for syscalls. We would not be able to restart a syscall otherwise. The signal trampoline does not need to flush the regiters anymore, because get_mcontext() already handles that. In fact, if we set up the context correctly, we do not need to have a trampoline at all. This change however only minimally changes the trampoline code. In follow-up commits this can be further optimized. Note that normally we preserve cfm and iip in the trapframe created by the EPC syscall path when we restore a context in set_mcontext() because those fields are not normally set for a synchronuous context. The kernel puts the return address and frame info of the syscall stub in there. By preserving these fields we hide this detail from userland which allows us to use setcontext(2) for user created contexts. However, sigreturn() is commonly called from the trampoline, which means that if we preserve cfm and iip in all cases, we would return to the trampoline after the sigreturn(), which means we hit the safety net: we call exit(2). So, we do not preserve cfm and iip when we have a synchronous context that also has scratch registers (the uncommon context created by sendsig() only), under the assumption that if such a context is created in userland, something special is going on and the use of cfm and iip is then just another quirk. All this is invisible in the common case. |
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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