Messages in this thread | | | From | Kees Cook <> | Subject | [PATCH v3 0/3] overflow: Introduce wrapping helpers | Date | Mon, 5 Feb 2024 01:12:28 -0800 |
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Hi,
v3: - reduce patches to just docs and new helpers; we don't need pointer fixes yet. v2: https://lore.kernel.org/all/20240130220218.it.154-kees@kernel.org/ v1: https://lore.kernel.org/lkml/20240129182845.work.694-kees@kernel.org/
In preparation for gaining instrumentation for signed[1], unsigned[2], and pointer[3] wrap-around, expand the overflow header to include wrap-around helpers that can be used to annotate arithmetic where wrapped calculations are expected (e.g. atomics).
After spending time getting the unsigned integer wrap-around sanitizer running warning-free on a basic x86_64 boot[4], I think the *_wrap() helpers first argument being the output type makes the most sense (as suggested by Rasmus).
-Kees
Link: https://github.com/KSPP/linux/issues/26 [1] Link: https://github.com/KSPP/linux/issues/27 [2] Link: https://github.com/KSPP/linux/issues/344 [3] Link: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=devel/overflow/enable-unsigned-sanitizer [4]
Kees Cook (3): overflow: Adjust check_*_overflow() kern-doc to reflect results overflow: Introduce add_wrap(), sub_wrap(), and mul_wrap() overflow: Introduce inc_wrap() and dec_wrap()
include/linux/overflow.h | 100 ++++++++++++++++++++++++++++++++++----- lib/overflow_kunit.c | 65 +++++++++++++++++++++++-- 2 files changed, 149 insertions(+), 16 deletions(-)
-- 2.34.1
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