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Date: Wed, 21 Feb 2024 20:10:08 +0000
From: Justin Stitt <justinstitt@google.com>
To: David Gow <davidgow@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Shuah Khan <skhan@linuxfoundation.org>,
	Guenter Roeck <linux@roeck-us.net>, Rae Moar <rmoar@google.com>,
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	Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>,
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Subject: Re: [PATCH 2/9] lib/cmdline: Fix an invalid format specifier in an
 assertion msg
Message-ID: <20240221201008.ez5tu7xvkedtln3o@google.com>
References: <20240221092728.1281499-1-davidgow@google.com>
 <20240221092728.1281499-3-davidgow@google.com>
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In-Reply-To: <20240221092728.1281499-3-davidgow@google.com>

Hi,

On Wed, Feb 21, 2024 at 05:27:15PM +0800, David Gow wrote:
> The correct format specifier for p - n (both p and n are pointers) is
> %td, as the type should be ptrdiff_t.

I think %tu is better. d specifies a signed type. I don't doubt that the
warning is fixed but I think %tu represents the type semantics here.

>
> This was discovered by annotating KUnit assertion macros with gcc's
> printf specifier, but note that gcc incorrectly suggested a %d or %ld
> specifier (depending on the pointer size of the architecture being
> built).
>
> Fixes: 0ea09083116d ("lib/cmdline: Allow get_options() to take 0 to validate the input")
> Signed-off-by: David Gow <davidgow@google.com>


> ---
>  lib/cmdline_kunit.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/cmdline_kunit.c b/lib/cmdline_kunit.c
> index d4572dbc9145..705b82736be0 100644
> --- a/lib/cmdline_kunit.c
> +++ b/lib/cmdline_kunit.c
> @@ -124,7 +124,7 @@ static void cmdline_do_one_range_test(struct kunit *test, const char *in,
>  			    n, e[0], r[0]);
>
>  	p = memchr_inv(&r[1], 0, sizeof(r) - sizeof(r[0]));
> -	KUNIT_EXPECT_PTR_EQ_MSG(test, p, NULL, "in test %u at %u out of bound", n, p - r);
> +	KUNIT_EXPECT_PTR_EQ_MSG(test, p, NULL, "in test %u at %td out of bound", n, p - r);
>  }
>
>  static void cmdline_test_range(struct kunit *test)
> --
> 2.44.0.rc0.258.g7320e95886-goog
>

Thanks
Justin