From patchwork Tue Sep 18 00:56:58 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11480 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 A561B23E53 for ; Tue, 18 Sep 2012 00:57:20 +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 0CB8EA18492 for ; Tue, 18 Sep 2012 00:57:19 +0000 (UTC) Received: by ieak11 with SMTP id k11so10081938iea.11 for ; Mon, 17 Sep 2012 17:57:19 -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:x-cbid:x-gm-message-state; bh=/8g0+CK9SHnqTxgcxALiuz52TsuNPZOUfYBUWpDQIHY=; b=fY4N0aHOyzANuyhF9c1LzyF8R/W+/ablpP0Xz2E3oKavUTH6bOMZAkHKAlEGZ4ZPVi hEUswH96JA0NFNZ8US9kQ1XII4q8zgwafkXSQnVAYua+b1mayGZYlElmxmyByMAd866S qawIVv8zDMBzjwiVhnVxvPQUCkjnddpGaOJYNJY29Y1OFU3LNBZ309DT5ayUl6PuF9Pf NcA5buHj7PGc+ZVngBVd/AoAA2ioOnPM2c7Fqhlu7tv02d84pTF7gwUEDaSC/U9kEFLM c2kVpSyic7K5X7qigB8gNgQHw/YSCeDKAkCDQlroD2cGwqp3uFEbL0h27vndpxfMKtNe ZW1w== Received: by 10.50.217.227 with SMTP id pb3mr8780555igc.28.1347929838887; Mon, 17 Sep 2012 17:57:18 -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 ex8csp346502igc; Mon, 17 Sep 2012 17:57:18 -0700 (PDT) Received: by 10.50.182.202 with SMTP id eg10mr8754301igc.56.1347929838279; Mon, 17 Sep 2012 17:57:18 -0700 (PDT) Received: from e6.ny.us.ibm.com (e6.ny.us.ibm.com. 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Violators will be prosecuted; Mon, 17 Sep 2012 20:57:15 -0400 Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8I0vEX6193230; Mon, 17 Sep 2012 20:57:14 -0400 Received: from d03av05.boulder.ibm.com (loopback [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8I0vDZa021107; Mon, 17 Sep 2012 18:57:14 -0600 Received: from kernel-pok.stglabs.ibm.com (kernel.stglabs.ibm.com [9.114.214.19]) by d03av05.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8I0vCaC021055; Mon, 17 Sep 2012 18:57:13 -0600 From: John Stultz To: stable@vger.kernel.org Cc: John Stultz , Peter Zijlstra , Prarit Bhargava , Zhouping Liu , Ingo Molnar , Thomas Gleixner Subject: [PATCH 1/3] 2.6.35.y: time: Improve sanity checking of timekeeping inputs Date: Mon, 17 Sep 2012 20:56:58 -0400 Message-Id: <1347929818-32548-1-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 x-cbid: 12091800-1976-0000-0000-000011766FA8 X-Gm-Message-State: ALoCoQkU93MrL2UzCWK0KKUqTDl7jGFr5SXF//9LkzfvLX+QZxEu/fLwEyTLYww4C25iBh0jdN2m Resending, as this one didn't seem to get out. 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 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 e1ceaa9..07f9d7b 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 ea3559f0..f040fb0 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 782f13d..4f760d4 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -337,7 +337,7 @@ 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); @@ -551,7 +551,20 @@ void __init timekeeping_init(void) struct timespec now, boot; read_persistent_clock(&now); + if (!timespec_valid(&now)) { + pr_warn("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)) { + pr_warn("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);