Re: [PATCH v2 3/3] objtool, kcsan: Add volatile read/write instrumentation to whitelist

[Dmitry Vyukov]

On Fri, 9 Sept 2022 at 09:38, Marco Elver <elver@xxxxxxxxxx> wrote:
>
> Adds KCSAN's volatile instrumentation to objtool's uaccess whitelist.
>
> Recent kernel change have shown that this was missing from the uaccess
> whitelist (since the first upstreamed version of KCSAN):
>
>   mm/gup.o: warning: objtool: fault_in_readable+0x101: call to __tsan_volatile_write1() with UACCESS enabled
>
> Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses")
> Signed-off-by: Marco Elver <elver@xxxxxxxxxx>

Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>

> ---
> v2:
> * Fix commit message.
> ---
>  tools/objtool/check.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index e55fdf952a3a..67afdce3421f 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -999,6 +999,16 @@ static const char *uaccess_safe_builtin[] = {
>         "__tsan_read_write4",
>         "__tsan_read_write8",
>         "__tsan_read_write16",
> +       "__tsan_volatile_read1",
> +       "__tsan_volatile_read2",
> +       "__tsan_volatile_read4",
> +       "__tsan_volatile_read8",
> +       "__tsan_volatile_read16",
> +       "__tsan_volatile_write1",
> +       "__tsan_volatile_write2",
> +       "__tsan_volatile_write4",
> +       "__tsan_volatile_write8",
> +       "__tsan_volatile_write16",
>         "__tsan_atomic8_load",
>         "__tsan_atomic16_load",
>         "__tsan_atomic32_load",
> --
> 2.37.2.789.g6183377224-goog
>