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2020-04-07lib: test_stackinit.c: XFAIL switch variable init testsKees Cook
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>
2019-06-05lib/test_stackinit: Handle Clang auto-initialization patternKees Cook
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>
2019-06-01treewide: fix typos of SPDX-License-IdentifierMasahiro Yamada
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>
2019-03-04lib: Introduce test_stackinit moduleKees Cook
Adds test for stack initialization coverage. We have several build options that control the level of stack variable initialization. This test lets us visualize which options cover which cases, and provide tests for some of the pathological padding conditions the compiler will sometimes fail to initialize. All options pass the explicit initialization cases and the partial initializers (even with padding): test_stackinit: u8_zero ok test_stackinit: u16_zero ok test_stackinit: u32_zero ok test_stackinit: u64_zero ok test_stackinit: char_array_zero ok test_stackinit: small_hole_zero ok test_stackinit: big_hole_zero ok test_stackinit: trailing_hole_zero ok test_stackinit: packed_zero ok test_stackinit: small_hole_dynamic_partial ok test_stackinit: big_hole_dynamic_partial ok test_stackinit: trailing_hole_dynamic_partial ok test_stackinit: packed_dynamic_partial ok test_stackinit: small_hole_static_partial ok test_stackinit: big_hole_static_partial ok test_stackinit: trailing_hole_static_partial ok test_stackinit: packed_static_partial ok test_stackinit: packed_static_all ok test_stackinit: packed_dynamic_all ok test_stackinit: packed_runtime_all ok The results of the other tests (which contain no explicit initialization), change based on the build's configured compiler instrumentation. No options: test_stackinit: small_hole_static_all FAIL (uninit bytes: 3) test_stackinit: big_hole_static_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_static_all FAIL (uninit bytes: 7) test_stackinit: small_hole_dynamic_all FAIL (uninit bytes: 3) test_stackinit: big_hole_dynamic_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_dynamic_all FAIL (uninit bytes: 7) test_stackinit: small_hole_runtime_partial FAIL (uninit bytes: 23) test_stackinit: big_hole_runtime_partial FAIL (uninit bytes: 127) test_stackinit: trailing_hole_runtime_partial FAIL (uninit bytes: 24) test_stackinit: packed_runtime_partial FAIL (uninit bytes: 24) test_stackinit: small_hole_runtime_all FAIL (uninit bytes: 3) test_stackinit: big_hole_runtime_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_runtime_all FAIL (uninit bytes: 7) test_stackinit: u8_none FAIL (uninit bytes: 1) test_stackinit: u16_none FAIL (uninit bytes: 2) test_stackinit: u32_none FAIL (uninit bytes: 4) test_stackinit: u64_none FAIL (uninit bytes: 8) test_stackinit: char_array_none FAIL (uninit bytes: 16) test_stackinit: switch_1_none FAIL (uninit bytes: 8) test_stackinit: switch_2_none FAIL (uninit bytes: 8) test_stackinit: small_hole_none FAIL (uninit bytes: 24) test_stackinit: big_hole_none FAIL (uninit bytes: 128) test_stackinit: trailing_hole_none FAIL (uninit bytes: 32) test_stackinit: packed_none FAIL (uninit bytes: 32) test_stackinit: user FAIL (uninit bytes: 32) test_stackinit: failures: 25 CONFIG_GCC_PLUGIN_STRUCTLEAK_USER=y This only tries to initialize structs with __user markings, so only the difference from above is now the "user" test passes: test_stackinit: small_hole_static_all FAIL (uninit bytes: 3) test_stackinit: big_hole_static_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_static_all FAIL (uninit bytes: 7) test_stackinit: small_hole_dynamic_all FAIL (uninit bytes: 3) test_stackinit: big_hole_dynamic_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_dynamic_all FAIL (uninit bytes: 7) test_stackinit: small_hole_runtime_partial FAIL (uninit bytes: 23) test_stackinit: big_hole_runtime_partial FAIL (uninit bytes: 127) test_stackinit: trailing_hole_runtime_partial FAIL (uninit bytes: 24) test_stackinit: packed_runtime_partial FAIL (uninit bytes: 24) test_stackinit: small_hole_runtime_all FAIL (uninit bytes: 3) test_stackinit: big_hole_runtime_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_runtime_all FAIL (uninit bytes: 7) test_stackinit: u8_none FAIL (uninit bytes: 1) test_stackinit: u16_none FAIL (uninit bytes: 2) test_stackinit: u32_none FAIL (uninit bytes: 4) test_stackinit: u64_none FAIL (uninit bytes: 8) test_stackinit: char_array_none FAIL (uninit bytes: 16) test_stackinit: switch_1_none FAIL (uninit bytes: 8) test_stackinit: switch_2_none FAIL (uninit bytes: 8) test_stackinit: small_hole_none FAIL (uninit bytes: 24) test_stackinit: big_hole_none FAIL (uninit bytes: 128) test_stackinit: trailing_hole_none FAIL (uninit bytes: 32) test_stackinit: packed_none FAIL (uninit bytes: 32) test_stackinit: user ok test_stackinit: failures: 24 CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF=y This initializes all structures passed by reference (scalars and strings remain uninitialized): test_stackinit: small_hole_static_all ok test_stackinit: big_hole_static_all ok test_stackinit: trailing_hole_static_all ok test_stackinit: small_hole_dynamic_all ok test_stackinit: big_hole_dynamic_all ok test_stackinit: trailing_hole_dynamic_all ok test_stackinit: small_hole_runtime_partial ok test_stackinit: big_hole_runtime_partial ok test_stackinit: trailing_hole_runtime_partial ok test_stackinit: packed_runtime_partial ok test_stackinit: small_hole_runtime_all ok test_stackinit: big_hole_runtime_all ok test_stackinit: trailing_hole_runtime_all ok test_stackinit: u8_none FAIL (uninit bytes: 1) test_stackinit: u16_none FAIL (uninit bytes: 2) test_stackinit: u32_none FAIL (uninit bytes: 4) test_stackinit: u64_none FAIL (uninit bytes: 8) test_stackinit: char_array_none FAIL (uninit bytes: 16) test_stackinit: switch_1_none FAIL (uninit bytes: 8) test_stackinit: switch_2_none FAIL (uninit bytes: 8) test_stackinit: small_hole_none ok test_stackinit: big_hole_none ok test_stackinit: trailing_hole_none ok test_stackinit: packed_none ok test_stackinit: user ok test_stackinit: failures: 7 CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y This initializes all variables, so it matches above with the scalars and arrays included: test_stackinit: small_hole_static_all ok test_stackinit: big_hole_static_all ok test_stackinit: trailing_hole_static_all ok test_stackinit: small_hole_dynamic_all ok test_stackinit: big_hole_dynamic_all ok test_stackinit: trailing_hole_dynamic_all ok test_stackinit: small_hole_runtime_partial ok test_stackinit: big_hole_runtime_partial ok test_stackinit: trailing_hole_runtime_partial ok test_stackinit: packed_runtime_partial ok test_stackinit: small_hole_runtime_all ok test_stackinit: big_hole_runtime_all ok test_stackinit: trailing_hole_runtime_all ok test_stackinit: u8_none ok test_stackinit: u16_none ok test_stackinit: u32_none ok test_stackinit: u64_none ok test_stackinit: char_array_none ok test_stackinit: switch_1_none ok test_stackinit: switch_2_none ok test_stackinit: small_hole_none ok test_stackinit: big_hole_none ok test_stackinit: trailing_hole_none ok test_stackinit: packed_none ok test_stackinit: user ok test_stackinit: all tests passed! Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>