ef226b1dc6
From Jake: iflib_encap calls bus_dmamap_load_mbuf_sg. Upon it returning EFBIG, an m_collapse and an m_defrag are attempted to shrink the mbuf cluster to fit within the DMA segment limitations. However, if we call m_defrag, and then bus_dmamap_load_mbuf_sg returns EFBIG on the now defragmented mbuf, we will continuously re-call bus_dmamap_load_mbuf_sg over and over. This happens because m_head isn't NULL, and remap is >1, so we don't try to m_collapse or m_defrag again. The only way we exit the loop is if m_head is NULL. However, m_head can't be modified by the call to bus_dmamap_load_mbuf_sg, because we don't pass it as a double pointer. I believe this will be an incredibly rare occurrence, because it is unlikely that bus_dmamap_load_mbuf_sg will actually fail on the second defragment with an EFBIG error. However, it still seems like a possibility that we should account for. Fix the exit check to ensure that if remap is >1, we will also exit, even if m_head is not NULL. Submitted by: Jacob Keller <jacob.e.keller@intel.com> Reviewed by: shurd@, gallatin@ MFC after: 1 week Sponsored by: Intel Corporation Differential Revision: https://reviews.freebsd.org/D19468 |
||
|---|---|---|
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README | ||
| README.md | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
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), config(8), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.
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.
stand Boot loader sources.
sys Kernel sources.
sys/<arch>/conf Kernel configuration files. GENERIC is the configuration
used in release builds. NOTES contains documentation of
all possible entries.
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:
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/current-stable.html