[PATCH v4 1/7] kcsan: Add atomic builtin stubs for 32-bit systems

[Max Filippov]

On Tue, Feb 7, 2023 at 7:22 PM Rohan McLure <rmclure at linux.ibm.com> wrote:
>
> KCSAN instruments calls to atomic builtins, and will in turn call these
> builtins itself. As such, architectures supporting KCSAN must have
> compiler support for these atomic primitives.
>
> Since 32-bit systems are unlikely to have 64-bit compiler builtins,
> provide a stub for each missing builtin, and use BUG() to assert
> unreachability.
>
> In commit 725aea873261 ("xtensa: enable KCSAN"), xtensa implements these
> locally, but does not advertise the fact with preprocessor macros. To
> avoid production of duplicate symbols, do not build the stubs on xtensa.
> A future patch will remove the xtensa implementation of these stubs.
>
> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>
> ---
> v4: New patch
> ---
>  kernel/kcsan/Makefile |  3 ++
>  kernel/kcsan/stubs.c  | 78 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 81 insertions(+)
>  create mode 100644 kernel/kcsan/stubs.c

Reviewed-by: Max Filippov <jcmvbkbc at gmail.com>

-- 
Thanks.
-- Max