KASAN enables the use of LLVM's AddressSanitizer in the kernel. This feature makes use of compiler instrumentation to validate memory accesses in the kernel and detect several types of bugs, including use-after-frees and out-of-bounds accesses. It is particularly effective when combined with test suites or syzkaller. KASAN has high CPU and memory usage overhead and so is not suited for production environments. The runtime and pmap maintain a shadow of the kernel map to store information about the validity of memory mapped at a given kernel address. The runtime implements a number of functions defined by the compiler ABI. These are prefixed by __asan. The compiler emits calls to __asan_load*() and __asan_store*() around memory accesses, and the runtime consults the shadow map to determine whether a given access is valid. kasan_mark() is called by various kernel allocators to update state in the shadow map. Updates to those allocators will come in subsequent commits. The runtime also defines various interceptors. Some low-level routines are implemented in assembly and are thus not amenable to compiler instrumentation. To handle this, the runtime implements these routines on behalf of the rest of the kernel. The sanitizer implementation validates memory accesses manually before handing off to the real implementation. The sanitizer in a KASAN-configured kernel can be disabled by setting the loader tunable debug.kasan.disable=1. Obtained from: NetBSD MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D29416 |
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.github/workflows | ||
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 | ||
.cirrus.yml | ||
.clang-format | ||
.gitattributes | ||
.gitignore | ||
COPYRIGHT | ||
LOCKS | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc1 | ||
Makefile.libcompat | ||
Makefile.sys.inc | ||
ObsoleteFiles.inc | ||
README.md | ||
RELNOTES | ||
UPDATING |
FreeBSD Source:
This is the top level of the FreeBSD source directory.
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), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
Source Roadmap:
Directory | Description |
---|---|
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 and gnu/COPYING.LIB 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 FreeBSD Handbook.