No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Kees Cook b688f369ae compiler_types: Introduce __nonstring_array
GCC has expanded support of the "nonstring" attribute so that it can be
applied to arrays of character arrays[1], which is needed to identify
correct static initialization of those kinds of objects. Since this was
not supported prior to GCC 15, we need to distinguish the usage of Linux's
existing __nonstring macro for the attribute for non-multi-dimensional
char arrays. Until GCC 15 is the minimum version, use __nonstring_array to
mark arrays of non-string character arrays. (Regular non-string character
arrays can continue to use __nonstring.) Once GCC 15 is the minimum
compiler version we can replace all uses of __nonstring_array with just
__nonstring and remove this macro.

This allows for changes like this:

-static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
+static const char table_sigs[][ACPI_NAMESEG_SIZE] __nonstring_array __initconst = {
        ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,

Which will silence the coming -Wunterminated-string-initialization
warnings in GCC 15:

In file included from ../include/acpi/actbl.h:371,                                                                   from ../include/acpi/acpi.h:26,                                                                     from ../include/linux/acpi.h:26,
                 from ../drivers/acpi/tables.c:19:
../include/acpi/actbl1.h:30:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars into 4 available) [-Wunterminated-string-initialization]
   30 | #define ACPI_SIG_BERT           "BERT"  /* Boot Error Record Table */
      |                                 ^~~~~~                                                      ../drivers/acpi/tables.c:400:9: note: in expansion of macro 'ACPI_SIG_BERT'                           400 |         ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
      |         ^~~~~~~~~~~~~                                                                       ../include/acpi/actbl1.h:31:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars into 4 available) [-Wunterminated-string-initialization]
   31 | #define ACPI_SIG_BGRT           "BGRT"  /* Boot Graphics Resource Table */
      |                                 ^~~~~~

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20250310214244.work.194-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
History 2025-03-12 13:21:09 -07:00
arch
block
certs
crypto
Documentation
drivers
fs
include
init
io_uring
ipc
kernel
lib
LICENSES
mm
net
rust
samples
scripts
security
sound
tools
usr
virt
.clang-format
.clippy.toml
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
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 reStructuredText 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.