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Date:   Sat, 23 Jul 2022 06:42:57 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>, ndesaulniers@google.com
CC:     arnd@arndb.de, gregkh@linuxfoundation.org, justinstitt@google.com,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        nathan@kernel.org, trix@redhat.com
Subject: Re: [PATCH v2] drivers: lkdtm: fix clang -Wformat warning
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On July 21, 2022 2:57:06 PM PDT, Justin Stitt <justinstitt@google=2Ecom> w=
rote:
>When building with Clang we encounter the following warning
>(ARCH=3Dhexagon + CONFIG_FRAME_WARN=3D0):
>| =2E=2E/drivers/misc/lkdtm/bugs=2Ec:107:3: error: format specifies type
>| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
>|                 REC_STACK_SIZE, recur_count);
>|                 ^~~~~~~~~~~~~~
>
>Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
>as well as maintain symmetry with `#define REC_STACK_SIZE
>(_AC(CONFIG_FRAME_WARN, UL) / 2)`=2E
>
>Link: https://github=2Ecom/ClangBuiltLinux/linux/issues/378
>Reported-by: Nathan Chancellor <nathan@kernel=2Eorg>
>Suggested-by: Nathan Chancellor <nathan@kernel=2Eorg>
>Suggested-by: Nick Desaulniers <ndesaulniers@google=2Ecom>
>Signed-off-by: Justin Stitt <justinstitt@google=2Ecom>

Thanks!

Acked-by: Kees Cook <keescook@chromium=2Eorg>
Fixes: 24cccab42c419 ("lkdtm/bugs: Adjust recursion test to avoid elision"=
)


--=20
Kees Cook