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    Subject[ 113/127] time: Move ktime_t overflow checking into timespec_valid_strict
    Date
    3.0-stable review patch.  If anyone has any objections, please let me know.

    ------------------


    commit cee58483cf56e0ba355fdd97ff5e8925329aa936 upstream

    Andreas Bombe reported that the added ktime_t overflow checking added to
    timespec_valid in commit 4e8b14526ca7 ("time: Improve sanity checking of
    timekeeping inputs") was causing problems with X.org because it caused
    timeouts larger then KTIME_T to be invalid.

    Previously, these large timeouts would be clamped to KTIME_MAX and would
    never expire, which is valid.

    This patch splits the ktime_t overflow checking into a new
    timespec_valid_strict function, and converts the timekeeping codes
    internal checking to use this more strict function.

    Reported-and-tested-by: Andreas Bombe <aeb@debian.org>
    Cc: Zhouping Liu <zliu@redhat.com>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Prarit Bhargava <prarit@redhat.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: John Stultz <john.stultz@linaro.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: John Stultz <john.stultz@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    include/linux/time.h | 7 +++++++
    kernel/time/timekeeping.c | 14 ++++++++++----
    2 files changed, 17 insertions(+), 4 deletions(-)

    --- a/include/linux/time.h
    +++ b/include/linux/time.h
    @@ -125,6 +125,13 @@ static inline bool timespec_valid(const
    /* Can't have more nanoseconds then a second */
    if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
    return false;
    + return true;
    +}
    +
    +static inline bool timespec_valid_strict(const struct timespec *ts)
    +{
    + if (!timespec_valid(ts))
    + return false;
    /* Disallow values that could overflow ktime_t */
    if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
    return false;
    --- a/kernel/time/timekeeping.c
    +++ b/kernel/time/timekeeping.c
    @@ -382,7 +382,7 @@ int do_settimeofday(const struct timespe
    struct timespec ts_delta;
    unsigned long flags;

    - if (!timespec_valid(tv))
    + if (!timespec_valid_strict(tv))
    return -EINVAL;

    write_seqlock_irqsave(&xtime_lock, flags);
    @@ -428,7 +428,7 @@ int timekeeping_inject_offset(struct tim
    timekeeping_forward_now();

    tmp = timespec_add(xtime, *ts);
    - if (!timespec_valid(&tmp)) {
    + if (!timespec_valid_strict(&tmp)) {
    ret = -EINVAL;
    goto error;
    }
    @@ -591,7 +591,7 @@ void __init timekeeping_init(void)
    struct timespec now, boot;

    read_persistent_clock(&now);
    - if (!timespec_valid(&now)) {
    + if (!timespec_valid_strict(&now)) {
    pr_warn("WARNING: Persistent clock returned invalid value!\n"
    " Check your CMOS/BIOS settings.\n");
    now.tv_sec = 0;
    @@ -599,7 +599,7 @@ void __init timekeeping_init(void)
    }

    read_boot_clock(&boot);
    - if (!timespec_valid(&boot)) {
    + if (!timespec_valid_strict(&boot)) {
    pr_warn("WARNING: Boot clock returned invalid value!\n"
    " Check your CMOS/BIOS settings.\n");
    boot.tv_sec = 0;
    @@ -649,6 +649,12 @@ static void update_sleep_time(struct tim
    */
    static void __timekeeping_inject_sleeptime(struct timespec *delta)
    {
    + if (!timespec_valid_strict(delta)) {
    + printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
    + "sleep delta value!\n");
    + return;
    + }
    +
    xtime = timespec_add(xtime, *delta);
    wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta);
    update_sleep_time(timespec_add(total_sleep_time, *delta));



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