cdfe89c7e1
The general stack protector is known to be weak and has pretty small coverage. While setting stack-protector-all would give better protection it would come with a performance cost: for this reason Google's Chrome OS team developed a new stack-protector-strong variant. In addition to the protections offered by -fstack-protector, the new option will guard any function that declares any type or length of local array, even those in structs or unions. It will also protect functions that use a local variable's address in a function argument or on the right-hand side of an assignment. The option was introduced in GCC-4.9, but support for it has been back-ported to our base GCC (r286074) and is also available in clang. The change was tested with dbench and doesn't introduce performance regressions. An exp-run over the ports tree revealed no failures when using the stricter stack-protector-all. Thanks to all testers involved. Reference: https://outflux.net/blog/archives/2014/01/27/fstack-protector-strong/ Tested by: pho, portmgr (antoine) Discussed with: secteam (delphij) Differential Revision: https://reviews.freebsd.org/D3463 PR: 203394 (exp-run) Relnotes: yes MFC: no (not supported in older clang)
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. See build(7) and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. 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. See build(7), config(8), and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information. 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 kernel configuration files reside in the sys/<arch>/conf sub-directory. GENERIC is the default configuration used in release builds. NOTES contains entries and documentation for all possible devices, not just those commonly used. 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. 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. 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: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html