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84679f04ce
When a software KASAN mode is enabled, the fortify tests emit warnings
on some architectures.
For example, for ARCH=arm, the combination of CONFIG_FORTIFY_SOURCE=y
and CONFIG_KASAN=y produces the following warnings:
TEST lib/test_fortify/read_overflow-memchr.log
warning: unsafe memchr() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memchr.c
TEST lib/test_fortify/read_overflow-memchr_inv.log
warning: unsafe memchr_inv() usage lacked '__read_overflow' symbol in lib/test_fortify/read_overflow-memchr_inv.c
TEST lib/test_fortify/read_overflow-memcmp.log
warning: unsafe memcmp() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memcmp.c
TEST lib/test_fortify/read_overflow-memscan.log
warning: unsafe memscan() usage lacked '__read_overflow' symbol in lib/test_fortify/read_overflow-memscan.c
TEST lib/test_fortify/read_overflow2-memcmp.log
warning: unsafe memcmp() usage lacked '__read_overflow2' warning in lib/test_fortify/read_overflow2-memcmp.c
[ more and more similar warnings... ]
Commit 9c2d1328f8 ("kbuild: provide reasonable defaults for tool
coverage") removed KASAN flags from non-kernel objects by default.
It was an intended behavior because lib/test_fortify/*.c are unit
tests that are not linked to the kernel.
As it turns out, some architectures require -fsanitize=kernel-(hw)address
to define __SANITIZE_ADDRESS__ for the fortify tests.
Without __SANITIZE_ADDRESS__ defined, arch/arm/include/asm/string.h
defines __NO_FORTIFY, thus excluding <linux/fortify-string.h>.
This issue does not occur on x86 thanks to commit 4ec4190be4
("kasan, x86: don't rename memintrinsics in uninstrumented files"),
but there are still some architectures that define __NO_FORTIFY
in such a situation.
Set KASAN_SANITIZE=y explicitly to the fortify tests.
Fixes: 9c2d1328f8 ("kbuild: provide reasonable defaults for tool coverage")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/all/0e8dee26-41cc-41ae-9493-10cd1a8e3268@app.fastmail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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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.