From patchwork Wed Sep 12 00:49:51 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11340 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 4A1AE23E29 for ; Wed, 12 Sep 2012 00:50:03 +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 8EE2E3D18DBC for ; Wed, 12 Sep 2012 00:50:02 +0000 (UTC) Received: by mail-ie0-f180.google.com with SMTP id k11so1938803iea.11 for ; Tue, 11 Sep 2012 17:50:02 -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-content-scanned:x-cbid:x-gm-message-state; bh=V4nHwJqf+4e8tIyN2iuGsyR7mVIsIjkJwR+PidpQzW8=; b=CY1Av/XGFoZFYYGWLWQ+TVaPf3jnJlNaGpchbXPao26Fa6XREDe/J3KKJeUNeEuBuO X4d9jiYKBJaV5WI3PQjAaHCD2a19UR8EPmCn3njT/ztvS5MPTZntW3MZ3pIbSff3WsdB bwZIeudt88BIxOxYOeNUEh7JApo8D66Rs6Yw9jwAHVbzilMoGAVHR4HUx0c2bXh1AP6e p2So13T5GBWIRf79csiuXVF6VEZZZ0pYDjXq8/nt5tcAhUdZA7HKYcI4f7GwJRr31Fol TCqmxaKTfe/+WrSuEmI6tFhwtU/imLCYABL29i8E65Y76QQ4FE8mHjO4fVmhNkvtRnSa cH0w== Received: by 10.50.207.106 with SMTP id lv10mr19214733igc.0.1347411002166; Tue, 11 Sep 2012 17:50:02 -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 ex8csp42595igc; Tue, 11 Sep 2012 17:50:01 -0700 (PDT) Received: by 10.50.5.196 with SMTP id u4mr19093322igu.41.1347411000716; Tue, 11 Sep 2012 17:50:00 -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 ix5si5144068igc.2.2012.09.11.17.50.00 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 11 Sep 2012 17:50:00 -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 ; Tue, 11 Sep 2012 20:50:00 -0400 Received: from d01dlp01.pok.ibm.com (9.56.250.166) by e4.ny.us.ibm.com (192.168.1.104) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 11 Sep 2012 20:49:57 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 09DB238C804F; Tue, 11 Sep 2012 20:49:57 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8C0nunW129334; Tue, 11 Sep 2012 20:49:56 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8C0nu2T002573; Tue, 11 Sep 2012 20:49:56 -0400 Received: from kernel-pok.stglabs.ibm.com (kernel.stglabs.ibm.com [9.114.214.19]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8C0nu3S002562; Tue, 11 Sep 2012 20:49:56 -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] 3.0.y: time: Improve sanity checking of timekeeping inputs Date: Tue, 11 Sep 2012 20:49:51 -0400 Message-Id: <1347410993-19004-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1347410993-19004-1-git-send-email-john.stultz@linaro.org> References: <1347410993-19004-1-git-send-email-john.stultz@linaro.org> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12091200-3534-0000-0000-00000C904898 X-Gm-Message-State: ALoCoQmnE4HyydTFvcXw7YVbBwp4dIx4opGLdrIl6HO0YEnlHBYKJ1NlM8aoVjTOLK9+B9oeIT5a 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 | 26 ++++++++++++++++++++++++-- 3 files changed, 44 insertions(+), 11 deletions(-) diff --git a/include/linux/ktime.h b/include/linux/ktime.h index 603bec2..06177ba10 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 b306178..c8f7233 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -107,11 +107,29 @@ 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 void read_persistent_clock(struct timespec *ts); extern void read_boot_clock(struct timespec *ts); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 678ae31..bfa6be73 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -382,7 +382,7 @@ int do_settimeofday(const 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); @@ -417,6 +417,8 @@ EXPORT_SYMBOL(do_settimeofday); int timekeeping_inject_offset(struct timespec *ts) { unsigned long flags; + struct timespec tmp; + int ret = 0; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; @@ -425,9 +427,16 @@ int timekeeping_inject_offset(struct timespec *ts) timekeeping_forward_now(); + tmp = timespec_add(xtime, *ts); + if (!timespec_valid(&tmp)) { + ret = -EINVAL; + goto error; + } + xtime = timespec_add(xtime, *ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); +error: /* even if we error out, we forwarded the time, so call update */ timekeeping_update(true); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -435,7 +444,7 @@ int timekeeping_inject_offset(struct timespec *ts) /* signal hrtimers about time change */ clock_was_set(); - return 0; + return ret; } EXPORT_SYMBOL(timekeeping_inject_offset); @@ -582,7 +591,20 @@ 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);