From patchwork Tue Sep 18 01:38:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11484 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 AD19924184 for ; Tue, 18 Sep 2012 01:38:57 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 15DE8A18D5D for ; Tue, 18 Sep 2012 01:38:56 +0000 (UTC) Received: by iafj25 with SMTP id j25so5550056iaf.11 for ; Mon, 17 Sep 2012 18:38:56 -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=OK3q3zSWzH7e26CV9VyHcba/iQvMKcAUBiVnTs7EcEE=; b=TEnw3ZaYu1IOKNkDiHlf9ER7C9kbgw+xcDo7ERZABxVW8mlcIgtzZ0xUpVMyiO9AzH uOHWP8BAk2h55PfonhilvIvzcGTRRkHD5BuWIQsHNHEeaHIsHwsP8Tr/e+/ZDm+d02vh t2TrA9TWmFIxjbYlskkT8YOHcTRdY01ugK/YnK9thW3EvS9pIbswAg/qEhFsuCC+DsgK v8ll5A5sD2noiiXAbQORtYp11Fo4ZmYHmueUnSVu3c9yvqvggASn6wMPfYJn7nVwCbNm jWcdJDi6ssH7Pz0Zc3WPO24u5IY0Z2HeHStEpKWDNSLISwgwg+KkfT6G4TTrnPj7U20H bXxA== Received: by 10.50.89.164 with SMTP id bp4mr8842228igb.28.1347932336225; Mon, 17 Sep 2012 18:38:56 -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 ex8csp348177igc; Mon, 17 Sep 2012 18:38:55 -0700 (PDT) Received: by 10.50.196.199 with SMTP id io7mr8897349igc.59.1347932335251; Mon, 17 Sep 2012 18:38:55 -0700 (PDT) Received: from e5.ny.us.ibm.com (e5.ny.us.ibm.com. [32.97.182.145]) by mx.google.com with ESMTPS id x3si16316162ice.81.2012.09.17.18.38.55 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 17 Sep 2012 18:38:55 -0700 (PDT) Received-SPF: neutral (google.com: 32.97.182.145 is neither permitted nor denied by best guess record for domain of john.stultz@linaro.org) client-ip=32.97.182.145; Authentication-Results: mx.google.com; spf=neutral (google.com: 32.97.182.145 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 e5.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 17 Sep 2012 21:38:54 -0400 Received: from d01relay05.pok.ibm.com (9.56.227.237) by e5.ny.us.ibm.com (192.168.1.105) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 17 Sep 2012 21:38:52 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8I1cp7C166076; Mon, 17 Sep 2012 21:38:51 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8I1cotX029964; Mon, 17 Sep 2012 21:38:51 -0400 Received: from kernel-pok.stglabs.ibm.com (kernel.stglabs.ibm.com [9.114.214.19]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8I1co9V029955; Mon, 17 Sep 2012 21:38:50 -0400 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] 2.6.34.y: time: Improve sanity checking of timekeeping inputs Date: Mon, 17 Sep 2012 21:38:45 -0400 Message-Id: <1347932327-33192-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1347932327-33192-1-git-send-email-john.stultz@linaro.org> References: <1347932327-33192-1-git-send-email-john.stultz@linaro.org> x-cbid: 12091801-5930-0000-0000-00000C346FF3 X-Gm-Message-State: ALoCoQkmgloVe21lz8mifHJXM7RSx3SB+ogt9466NsDgRUaTn7iQd75EsEEhrQh9QElkoEf0MErk 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 156fd67..0d59077 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 ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) + if (!timespec_valid(tv)) return -EINVAL; write_seqlock_irqsave(&xtime_lock, flags); @@ -559,7 +559,20 @@ 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);