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From:   Brendan Higgins <brendanhiggins@google.com>
Date:   Mon, 2 Dec 2019 08:18:32 -0800
Message-ID: <CAFd5g44z0v5ULZeNDb=GgdaMaBO8wTCoUCp6fv0fnWEzRZuRmw@mail.gmail.com>
Subject: Re: [PATCH] fs/ext4/inode-test: Fix inode test on 32 bit platforms.
To:     Iurii Zaikin <yzaikin@google.com>
Cc:     Shuah Khan <skhan@linuxfoundation.org>,
        "Theodore Ts'o" <tytso@mit.edu>, geert@linux-m68k.org,
        linux-ext4@vger.kernel.org,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        KUnit Development <kunit-dev@googlegroups.com>
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On Wed, Nov 27, 2019 at 10:55 AM Iurii Zaikin <yzaikin@google.com> wrote:
>
> Fixes the issue caused by the fact that in C in the expression
> of the form -1234L only 1234L is the actual literal, the unary
> minus is an operation applied to the literal. Which means that
> to express the lower bound for the type one has to negate the
> upper bound and subtract 1.
> Original error:
> Expected test_data[i].expected.tv_sec == timestamp.tv_sec, but
> test_data[i].expected.tv_sec == -2147483648
> timestamp.tv_sec == 2147483648
> 1901-12-13 Lower bound of 32bit < 0 timestamp, no extra bits: msb:1
> lower_bound:1 extra_bits: 0
> Expected test_data[i].expected.tv_sec == timestamp.tv_sec, but
> test_data[i].expected.tv_sec == 2147483648
> timestamp.tv_sec == 6442450944
> 2038-01-19 Lower bound of 32bit <0 timestamp, lo extra sec bit on:
> msb:1 lower_bound:1 extra_bits: 1
> Expected test_data[i].expected.tv_sec == timestamp.tv_sec, but
> test_data[i].expected.tv_sec == 6442450944
> timestamp.tv_sec == 10737418240
> 2174-02-25 Lower bound of 32bit <0 timestamp, hi extra sec bit on:
> msb:1 lower_bound:1 extra_bits: 2
> not ok 1 - inode_test_xtimestamp_decoding
> not ok 1 - ext4_inode_test
>
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Iurii Zaikin <yzaikin@google.com>
> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>

Acked-by: Brendan Higgins <brendanhiggins@google.com>

Thanks for taking care of this so quickly!