system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-06 18:01:05 +00:00
Code Issues Packages Projects Releases Wiki Activity
781900 commits 7 branches 851 tags 6.6 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
Find a file
Masahiro Yamada 81b4568348 compiler.h: give up __compiletime_assert_fallback() 
__compiletime_assert_fallback() is supposed to stop building earlier
by using the negative-array-size method in case the compiler does not
support "error" attribute, but has never worked like that.

You can simply try:

    BUILD_BUG_ON(1);

GCC immediately terminates the build, but Clang does not report
anything because Clang does not support the "error" attribute now.
It will later fail at link time, but __compiletime_assert_fallback()
is not working at least.

The root cause is commit 1d6a0d19c8 ("bug.h: prevent double evaluation
of `condition' in BUILD_BUG_ON").  Prior to that commit, BUILD_BUG_ON()
was checked by the negative-array-size method *and* the link-time trick.
Since that commit, the negative-array-size is not effective because
'__cond' is no longer constant.  As the comment in <linux/build_bug.h>
says, GCC (and Clang as well) only emits the error for obvious cases.

When '__cond' is a variable,

    ((void)sizeof(char[1 - 2 * __cond]))

... is not obvious for the compiler to know the array size is negative.

Reverting that commit would break BUILD_BUG() because negative-size-array
is evaluated before the code is optimized out.

Let's give up __compiletime_assert_fallback().  This commit does not
change the current behavior since it just rips off the useless code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-10-11 08:17:50 -07:00
arch ARM: SoC fixes 2018-09-02 10:44:28 -07:00
block block: bsg: move atomic_t ref_count variable to refcount API 2018-08-27 19:17:02 -06:00
certs
crypto
Documentation linux-watchdog 4.19-rc2 tag 2018-09-01 13:17:15 -07:00
drivers Devicetree updates for 4.19-rc2: 2018-09-02 10:56:01 -07:00
firmware
fs Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
include compiler.h: give up __compiletime_assert_fallback() 2018-10-11 08:17:50 -07:00
init
ipc
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 10:09:35 -07:00
lib Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
LICENSES
mm notifier: Remove notifier header file wherever not used 2018-08-30 12:56:40 +02:00
net Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 09:41:45 -07:00
samples
scripts Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-02 10:11:30 -07:00
security
sound
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-08-27 11:59:39 -07:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Fix up libata MAINTAINERS entry 2018-08-27 08:07:25 -07:00
Makefile Linux 4.19-rc2 2018-09-02 14:37:30 -07:00
README

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.