The tests for initializing a variable defined between a switch statement's
test and its first "case" statement are currently not initialized in
Clang[1] nor the proposed auto-initialization feature in GCC.
We should retain the test (so that we can evaluate compiler fixes), but
mark it as an "expected fail". The rest of the kernel source will be
adjusted to avoid this corner case.
Also disable -Wswitch-unreachable for the test so that the intentionally
broken code won't trigger warnings for GCC (nor future Clang) when
initialization happens this unhandled place.
[1] https://bugs.llvm.org/show_bug.cgi?id=44916
Suggested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jann Horn <jannh@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Link: http://lkml.kernel.org/r/202002191358.2897A07C6@keescook
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While the gcc plugin for automatic stack variable initialization (i.e.
CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) performs initialization with
0x00 bytes, the Clang automatic stack variable initialization (i.e.
CONFIG_INIT_STACK_ALL) uses various type-specific patterns that are
typically 0xAA. Therefore the stackinit selftest has been fixed to check
that bytes are no longer the test fill pattern of 0xFF (instead of looking
for bytes that have become 0x00). This retains the test coverage for the
0x00 pattern of the gcc plugin while adding coverage for the mostly 0xAA
pattern of Clang.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Prior to the adoption of SPDX, it was difficult for tools to determine
the correct license due to incomplete or badly formatted license text.
The SPDX solves this issue, assuming people can correctly spell
"SPDX-License-Identifier" although this assumption is broken in some
places.
Since scripts/spdxcheck.py parses only lines that exactly matches to
the correct tag, it cannot (should not) detect this kind of error.
If the correct tag is missing, scripts/checkpatch.pl warns like this:
WARNING: Missing or malformed SPDX-License-Identifier tag in line *
So, people should notice it before the patch submission, but in reality
broken tags sometimes slip in. The checkpatch warning is not useful for
checking the committed files globally since large number of files still
have no SPDX tag.
Also, I am not sure about the legal effect when the SPDX tag is broken.
Anyway, these typos are absolutely worth fixing. It is pretty easy to
find suspicious lines by grep.
$ git grep --not -e SPDX-License-Identifier --and -e SPDX- -- \
:^LICENSES :^scripts/spdxcheck.py :^*/license-rules.rst
arch/arm/kernel/bugs.c:// SPDX-Identifier: GPL-2.0
drivers/phy/st/phy-stm32-usbphyc.c:// SPDX-Licence-Identifier: GPL-2.0
drivers/pinctrl/sh-pfc/pfc-r8a77980.c:// SPDX-Lincense-Identifier: GPL 2.0
lib/test_stackinit.c:// SPDX-Licenses: GPLv2
sound/soc/codecs/max9759.c:// SPDX-Licence-Identifier: GPL-2.0
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kees Cook