From patchwork Tue Sep 18 02:32:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11486 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 8B53923E29 for ; Tue, 18 Sep 2012 02:32:34 +0000 (UTC) Received: from mail-ie0-f180.google.com (mail-ie0-f180.google.com [209.85.223.180]) by fiordland.canonical.com (Postfix) with ESMTP id 11DD0A18E04 for ; Tue, 18 Sep 2012 02:32:33 +0000 (UTC) Received: by mail-ie0-f180.google.com with SMTP id k11so10188650iea.11 for ; Mon, 17 Sep 2012 19:32:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:from:to:cc :subject:date:message-id:x-mailer:in-reply-to:references:x-cbid :x-gm-message-state; bh=SL2+c3SQu4dVFowcUaXtpiZG0nglTM0bfGPkWU0b1Yc=; b=gRYfqS41kp+GN7fxN1iYrSRlZX42VWoajNw1NsZphr8rMo4jwtpPfH/+4pRXkTFaQJ ZLssb40JlOZ9Vqt6QirjvbKsCY6OGPBcB4fKuKbAQis5G8qvLBF1vARJ+E/NKMqqQFPZ yghFevnssP9f+ENntBc9rANdcnzLdbhWrhU8+1czQo3srsvvBxs91hqczvQqzqvN7Ayh uw1VDMVcfE6R9ugyrLlxnJ41HFoSu3Uxui18uCQPYXkuHCm8JUSLP1kwRGZIx5AYInZT zvSX6SlfMIYbf/wG95qXmx2kMMYk5e2yBWl05nKwe+6lcgKXQ3CG0j8vM+pTW1mQdbMA B7ng== Received: by 10.42.109.194 with SMTP id m2mr10445821icp.48.1347935553752; Mon, 17 Sep 2012 19:32:33 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.50.184.232 with SMTP id ex8csp349589igc; Mon, 17 Sep 2012 19:32:33 -0700 (PDT) Received: by 10.50.186.132 with SMTP id fk4mr8955492igc.41.1347935552913; Mon, 17 Sep 2012 19:32:32 -0700 (PDT) Received: from e4.ny.us.ibm.com (e4.ny.us.ibm.com. [32.97.182.144]) by mx.google.com with ESMTPS id nu6si16482060icb.5.2012.09.17.19.32.32 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 17 Sep 2012 19:32:32 -0700 (PDT) Received-SPF: neutral (google.com: 32.97.182.144 is neither permitted nor denied by best guess record for domain of john.stultz@linaro.org) client-ip=32.97.182.144; Authentication-Results: mx.google.com; spf=neutral (google.com: 32.97.182.144 is neither permitted nor denied by best guess record for domain of john.stultz@linaro.org) smtp.mail=john.stultz@linaro.org Received: from /spool/local by e4.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 17 Sep 2012 22:32:31 -0400 Received: from d01relay03.pok.ibm.com (9.56.227.235) by e4.ny.us.ibm.com (192.168.1.104) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 17 Sep 2012 22:32:16 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8I2WGA8146602; Mon, 17 Sep 2012 22:32:16 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8I2WFxV008690; Mon, 17 Sep 2012 23:32:16 -0300 Received: from kernel-pok.stglabs.ibm.com (kernel.stglabs.ibm.com [9.114.214.19]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8I2WDhG008571; Mon, 17 Sep 2012 23:32:15 -0300 From: John Stultz To: stable@vger.kernel.org Cc: John Stultz , Peter Zijlstra , Prarit Bhargava , Zhouping Liu , Ingo Molnar , Thomas Gleixner , Linux Kernel Subject: [PATCH 1/3] 2.6.32.y: time: Improve sanity checking of timekeeping inputs Date: Mon, 17 Sep 2012 22:32:08 -0400 Message-Id: <1347935530-33767-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1347935530-33767-1-git-send-email-john.stultz@linaro.org> References: <1347935530-33767-1-git-send-email-john.stultz@linaro.org> x-cbid: 12091802-3534-0000-0000-00000CD663C8 X-Gm-Message-State: ALoCoQlSBY+1j5R01p2HH2TQImzZ+da4hNp4E4Uos8EEkwfVj9F8gRCtJqBGeGpsy4AmFg2TuFL+ This is a -stable backport of 4e8b14526ca7fb046a81c94002c1c43b6fdf0e9b Unexpected behavior could occur if the time is set to a value large enough to overflow a 64bit ktime_t (which is something larger then the year 2262). Also unexpected behavior could occur if large negative offsets are injected via adjtimex. So this patch improves the sanity check timekeeping inputs by improving the timespec_valid() check, and then makes better use of timespec_valid() to make sure we don't set the time to an invalid negative value or one that overflows ktime_t. Note: This does not protect from setting the time close to overflowing ktime_t and then letting natural accumulation cause the overflow. Reported-by: CAI Qian Reported-by: Sasha Levin Signed-off-by: John Stultz Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Zhouping Liu Cc: Ingo Molnar Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Cc: Linux Kernel Signed-off-by: John Stultz --- include/linux/ktime.h | 7 ------- include/linux/time.h | 22 ++++++++++++++++++++-- kernel/time/timekeeping.c | 15 ++++++++++++++- 3 files changed, 34 insertions(+), 10 deletions(-) diff --git a/include/linux/ktime.h b/include/linux/ktime.h index ce59832..ecdf64e 100644 --- a/include/linux/ktime.h +++ b/include/linux/ktime.h @@ -58,13 +58,6 @@ union ktime { typedef union ktime ktime_t; /* Kill this */ -#define KTIME_MAX ((s64)~((u64)1 << 63)) -#if (BITS_PER_LONG == 64) -# define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) -#else -# define KTIME_SEC_MAX LONG_MAX -#endif - /* * ktime_t definitions when using the 64-bit scalar representation: */ diff --git a/include/linux/time.h b/include/linux/time.h index 6e026e4..146b6f3 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -91,11 +91,29 @@ static inline struct timespec timespec_sub(struct timespec lhs, return ts_delta; } +#define KTIME_MAX ((s64)~((u64)1 << 63)) +#if (BITS_PER_LONG == 64) +# define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) +#else +# define KTIME_SEC_MAX LONG_MAX +#endif + /* * Returns true if the timespec is norm, false if denorm: */ -#define timespec_valid(ts) \ - (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC)) +static inline bool timespec_valid(const struct timespec *ts) +{ + /* Dates before 1970 are bogus */ + if (ts->tv_sec < 0) + return false; + /* Can't have more nanoseconds then a second */ + if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) + return false; + /* Disallow values that could overflow ktime_t */ + if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX) + return false; + return true; +} extern struct timespec xtime; extern struct timespec wall_to_monotonic; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3f7e53f..85d51c4 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -354,7 +354,7 @@ int do_settimeofday(struct timespec *tv) struct timespec ts_delta; unsigned long flags; - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) + if (!timespec_valid(tv)) return -EINVAL; write_seqlock_irqsave(&xtime_lock, flags); @@ -570,7 +570,20 @@ void __init timekeeping_init(void) struct timespec now, boot; read_persistent_clock(&now); + if (!timespec_valid(&now)) { + printk("WARNING: Persistent clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + now.tv_sec = 0; + now.tv_nsec = 0; + } + read_boot_clock(&boot); + if (!timespec_valid(&boot)) { + printk("WARNING: Boot clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + boot.tv_sec = 0; + boot.tv_nsec = 0; + } write_seqlock_irqsave(&xtime_lock, flags);