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| author | John Stultz <john.stultz@linaro.org> | 2012-09-11 15:04:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-02 10:30:36 -0700 |
| commit | 9a227fcb842a03fce5b8a6da0da40f5601ec6908 (patch) | |
| tree | d186f0f90e021d9fc9a35ab009cdcab3e315c8a2 | |
| parent | 80257cbe62ea0919153c43421746269ab68473bf (diff) | |
| download | lwn-9a227fcb842a03fce5b8a6da0da40f5601ec6908.tar.gz lwn-9a227fcb842a03fce5b8a6da0da40f5601ec6908.zip | |
time: Move ktime_t overflow checking into timespec_valid_strict
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>
| -rw-r--r-- | include/linux/time.h | 7 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 10 |
2 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/time.h b/include/linux/time.h index ac3118640e5c..03dce74e217c 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -125,6 +125,13 @@ static inline bool timespec_valid(const struct timespec *ts) /* 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; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 104d549f9df1..12843e9f6d59 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -385,7 +385,7 @@ int do_settimeofday(const struct timespec *tv) struct timespec ts_delta; unsigned long flags; - if (!timespec_valid(tv)) + if (!timespec_valid_strict(tv)) return -EINVAL; write_seqlock_irqsave(&timekeeper.lock, flags); @@ -431,7 +431,7 @@ int timekeeping_inject_offset(struct timespec *ts) timekeeping_forward_now(); tmp = timespec_add(timekeeper.xtime, *ts); - if (!timespec_valid(&tmp)) { + if (!timespec_valid_strict(&tmp)) { ret = -EINVAL; goto error; } @@ -608,7 +608,7 @@ 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; @@ -616,7 +616,7 @@ 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; @@ -667,7 +667,7 @@ static void update_sleep_time(struct timespec t) */ static void __timekeeping_inject_sleeptime(struct timespec *delta) { - if (!timespec_valid(delta)) { + if (!timespec_valid_strict(delta)) { printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " "sleep delta value!\n"); return; |