FreeBSD src
9ed61314ff
foreign per-CPU pages in cpu_ipi_send() in order to get the module IDs of the other CPUs can cause a page fault. If this happens when doing a TLB shootdown while dealing with another page fault this causes a panic due to the recursive page fault. As I don't spot other code that assumes or requires that accessing foreign per-CPU pages must not page fault solve this by adding a statically allocated (and therefore locked in the kernel pages) array which establishes a FreeBSD CPU ID -> module ID relation and use that in cpu_ipi_selected() (instead of statically allocating the per-CPU pages which would just waste memory on say a dual CPU machine as sun4u theoretically supports up to 128 CPUs or wasting dTLB slots for the foreign per-CPU pages). [1] - Fix a potential race in cpu_ipi_send(); as we don't serialize the access to cpu_ipi_selected() between MI and MD use (only MI-MI and MD-MD) we might catch the NACK bit caused by sending another IPI. Solve this by checking the NACK bit in the contents of the interrupt dispatch status reg read while interrupts were still turned off instead of reading that reg anew after interrupts were turned on again. This is also what the CPU docs suggest to do. - Add a workaround for the SpitFire erratum #54 bug (affecting interrupt dispatch). While public info regarding what this CPU bug actually causes is not available testing shows that with the workaround in place it's less likely to get a "couldn't send ipi" panic, it doesn't solve these panics entirely though. [2] Reported by: kris [1] Some clue from: kmacy [1] Info from: Linux, OpenSolaris [2] Additional testing by: kris MFC after: 3 days |
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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 | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| 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, 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. rescue Build system for statically linked /rescue utilities. 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