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    Subject[RFC][PATCH 0/5] Fixes for abs() usage on 64bit values
    Date
    As noted in include/linux/kernel.h:
    "abs() should not be used for 64-bit types (s64, u64, long long)
    - use abs64() for those."

    Unfortunately, there are quite a number of places where abs()
    was used w/ 64bit values in the kernel, and the results are
    then silently capped to 32-bit values on 32-bit systems.

    This series tries to address the problematic sites I found,
    and then introduces a patch which modifies abs() so that the
    build will fail if a 64-bit type is passed to it on a 32-bit
    machine.

    I'm sure there are additional sites that will need fixing,
    but hopefully this will make them easy to find.

    Comments and feedback would be greatly appreciated!

    Thanks
    -john

    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Cc: Michal Nazarewicz <mina86@mina86.com>
    Cc: Prarit Bhargava <prarit@redhat.com>
    Cc: Richard Cochran <richardcochran@gmail.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: "Theodore Ts'o" <tytso@mit.edu>
    Cc: Andreas Dilger <adilger.kernel@dilger.ca>
    Cc: Dave Chinner <dchinner@redhat.com>
    Cc: Tejun Heo <tj@kernel.org>
    Cc: Joe Perches <joe@perches.com>


    John Stultz (5):
    clocksource: Fix abs() usage w/ 64bit values
    time: Fix abs() usage with 64-bit values.
    ext4: Fix abs() usage in ext4_mb_check_group_pa
    percpu: Fix abs() usage in percpu_counter_compare()
    abs(): Provide build error on passing 64bit value to abs()

    fs/ext4/mballoc.c | 4 ++--
    include/linux/kernel.h | 3 +++
    kernel/time/clocksource.c | 2 +-
    kernel/time/timekeeping.c | 2 +-
    lib/percpu_counter.c | 2 +-
    5 files changed, 8 insertions(+), 5 deletions(-)

    --
    1.9.1



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