From 7d607e3f0b69385d5bad235de855aafd724a728f Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 17 Sep 2012 21:38:47 -0400 Subject: [PATCH] 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 Cc: Zhouping Liu Cc: Ingo Molnar Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz Signed-off-by: Linus Torvalds Cc: Linux Kernel Signed-off-by: John Stultz Signed-off-by: Paul Gortmaker --- include/linux/time.h | 7 +++++++ kernel/time/timekeeping.c | 6 +++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index 146b6f3c23b9..bc93987d05a0 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -109,6 +109,13 @@ 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 bbdad71aa90f..21cd75b3d8c8 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -343,7 +343,7 @@ int do_settimeofday(struct timespec *tv) struct timespec ts_delta; unsigned long flags; - if (!timespec_valid(tv)) + if (!timespec_valid_strict(tv)) return -EINVAL; write_seqlock_irqsave(&xtime_lock, flags); @@ -559,7 +559,7 @@ void __init timekeeping_init(void) struct timespec now, boot; read_persistent_clock(&now); - if (!timespec_valid(&now)) { + if (!timespec_valid_strict(&now)) { printk("WARNING: Persistent clock returned invalid value!\n" " Check your CMOS/BIOS settings.\n"); now.tv_sec = 0; @@ -567,7 +567,7 @@ void __init timekeeping_init(void) } read_boot_clock(&boot); - if (!timespec_valid(&boot)) { + if (!timespec_valid_strict(&boot)) { printk("WARNING: Boot clock returned invalid value!\n" " Check your CMOS/BIOS settings.\n"); boot.tv_sec = 0; -- 2.39.5