From patchwork Tue Sep 11 19:04:17 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11331 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 A035F23EFE for ; Tue, 11 Sep 2012 19:04:51 +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 3A2F73D01840 for ; Tue, 11 Sep 2012 19:04:51 +0000 (UTC) Received: by mail-ie0-f180.google.com with SMTP id k11so1468070iea.11 for ; Tue, 11 Sep 2012 12:04:51 -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=f7waQjjYyIhv/n62bL8QCNNTvw6PNGbkw1Hi2WNNDsk=; b=a+lcrhrFOOmZ2+zzmcXhRNrVbTxip7aAjukOubUTlVAofF1sgV76ZrAGqXuTNkdEDZ FMMBho7MAXAxXDjeyTN+CvXMhhvbjWP7X4Mgj241r0srjv/YbfAtts78R6lxNM/xZ+E4 f+BE3nyAin43yZTOoXBlIiTg3DEF6GTMO9eIRcbFcRaWAk8CO9UEfpOaakn/xfYX/pcu ZchJ39a091FO17kCvbRLkeqnMGD3IRSZAvRd5SsoanTzIqWC4zPd6HSZ04lKwR7Ph4ZY 1hqe6vf167aKtnqyAyHh/hK3DqZQwfheCqQSzLJesOpHS8by2QSKB+i98CPo78jvq1d6 +gBA== Received: by 10.50.45.162 with SMTP id o2mr18389159igm.0.1347390290971; Tue, 11 Sep 2012 12:04:50 -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 ex8csp29253igc; Tue, 11 Sep 2012 12:04:50 -0700 (PDT) Received: by 10.236.77.229 with SMTP id d65mr16813778yhe.124.1347390289900; Tue, 11 Sep 2012 12:04:49 -0700 (PDT) Received: from e9.ny.us.ibm.com (e9.ny.us.ibm.com. [32.97.182.139]) by mx.google.com with ESMTPS id s10si3326275ano.20.2012.09.11.12.04.49 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 11 Sep 2012 12:04:49 -0700 (PDT) Received-SPF: neutral (google.com: 32.97.182.139 is neither permitted nor denied by best guess record for domain of john.stultz@linaro.org) client-ip=32.97.182.139; Authentication-Results: mx.google.com; spf=neutral (google.com: 32.97.182.139 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 e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 11 Sep 2012 15:04:49 -0400 Received: from d01dlp01.pok.ibm.com (9.56.250.166) by e9.ny.us.ibm.com (192.168.1.109) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 11 Sep 2012 15:04:48 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id A82AF38C806A; Tue, 11 Sep 2012 15:04:36 -0400 (EDT) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8BJ4a5q155056; Tue, 11 Sep 2012 15:04:36 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8BJ4Z5e017851; Tue, 11 Sep 2012 16:04:35 -0300 Received: from kernel-pok.stglabs.ibm.com (kernel.stglabs.ibm.com [9.114.214.19]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8BJ4Mat015936; Tue, 11 Sep 2012 16:04:22 -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] 3.4.y: time: Improve sanity checking of timekeeping inputs Date: Tue, 11 Sep 2012 15:04:17 -0400 Message-Id: <1347390259-54838-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1347390259-54838-1-git-send-email-john.stultz@linaro.org> References: <1347390259-54838-1-git-send-email-john.stultz@linaro.org> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12091119-7182-0000-0000-000002970C3A X-Gm-Message-State: ALoCoQk+M1YDoHXpJd5qZN+fVT0nZwbTlyI9g2HnQwKm1ySIZaLS1nuUzYrCM+GgVxvlyH1KIcRn 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 8da5129..ac31186 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 7c50de8..dd31d0e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -385,7 +385,7 @@ 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(&timekeeper.lock, flags); @@ -420,6 +420,8 @@ 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; @@ -428,10 +430,17 @@ int timekeeping_inject_offset(struct timespec *ts) timekeeping_forward_now(); + tmp = timespec_add(timekeeper.xtime, *ts); + if (!timespec_valid(&tmp)) { + ret = -EINVAL; + goto error; + } + timekeeper.xtime = timespec_add(timekeeper.xtime, *ts); timekeeper.wall_to_monotonic = timespec_sub(timekeeper.wall_to_monotonic, *ts); +error: /* even if we error out, we forwarded the time, so call update */ timekeeping_update(true); write_sequnlock_irqrestore(&timekeeper.lock, flags); @@ -439,7 +448,7 @@ int timekeeping_inject_offset(struct timespec *ts) /* signal hrtimers about time change */ clock_was_set(); - return 0; + return ret; } EXPORT_SYMBOL(timekeeping_inject_offset); @@ -599,7 +608,20 @@ 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; + } seqlock_init(&timekeeper.lock);