No description
  • C 97%
  • Assembly 1%
  • Shell 0.6%
  • Rust 0.5%
  • Python 0.4%
  • Other 0.3%
Find a file
Nick Desaulniers 0d362be5b1 Makefile: link with -z noexecstack --no-warn-rwx-segments
Users of GNU ld (BFD) from binutils 2.39+ will observe multiple
instances of a new warning when linking kernels in the form:

  ld: warning: vmlinux: missing .note.GNU-stack section implies executable stack
  ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
  ld: warning: vmlinux has a LOAD segment with RWX permissions

Generally, we would like to avoid the stack being executable.  Because
there could be a need for the stack to be executable, assembler sources
have to opt-in to this security feature via explicit creation of the
.note.GNU-stack feature (which compilers create by default) or command
line flag --noexecstack.  Or we can simply tell the linker the
production of such sections is irrelevant and to link the stack as
--noexecstack.

LLVM's LLD linker defaults to -z noexecstack, so this flag isn't
strictly necessary when linking with LLD, only BFD, but it doesn't hurt
to be explicit here for all linkers IMO.  --no-warn-rwx-segments is
currently BFD specific and only available in the current latest release,
so it's wrapped in an ld-option check.

While the kernel makes extensive usage of ELF sections, it doesn't use
permissions from ELF segments.

Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Link: https://github.com/llvm/llvm-project/issues/57009
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-08-10 18:29:34 -07:00
arch - hugetlb_vmemmap cleanups from Muchun Song 2022-08-10 11:18:00 -07:00
block
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation rpmsg fixes for v5.20 2022-08-10 11:28:14 -07:00
drivers hwmon fixes for v6.0-rc1 2022-08-10 11:30:16 -07:00
fs NFS client updates for Linux 5.20 2022-08-10 14:04:32 -07:00
include NFS client updates for Linux 5.20 2022-08-10 14:04:32 -07:00
init Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
io_uring
ipc
kernel cxl for 6.0 2022-08-10 11:07:26 -07:00
lib
LICENSES
mm - hugetlb_vmemmap cleanups from Muchun Song 2022-08-10 11:18:00 -07:00
net NFS client updates for Linux 5.20 2022-08-10 14:04:32 -07:00
samples
scripts Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
security + Features 2022-08-10 10:53:22 -07:00
sound
tools cxl for 6.0 2022-08-10 11:07:26 -07:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Pin control bulk changes for v6.0: 2022-08-10 11:01:44 -07:00
Makefile Makefile: link with -z noexecstack --no-warn-rwx-segments 2022-08-10 18:29:34 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.