Merge branch 'akpm' (fixes from Andrew)

Merge emailed fixes from Andrew Morton:
 "Bunch of fixes:

   - delayed IPC updates.  I held back on this because of some possible
     outstanding bug reports, but they appear to have been addressed in
     later versions

   - A bunch of MAINTAINERS updates

   - Yet Another RTC driver.  I'd held this back while a couple of
     little issues were being worked out.

  I'm expecting an intrusive-but-simple patchset from Joe Perches which
  splits up printk.c into kernel/printk/*.  That will be a pig to
  maintain for two months so if it passes testing I'd like to get it
  upstream after a week or so."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  printk: fix incorrect length from print_time() when seconds > 99999
  drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time
  drivers/rtc/rtc-vt8500.c: correct handling of CR_24H bitfield
  rtc: add RTC driver for TPS6586x
  MAINTAINERS: fix drivers/staging/sm7xx/
  MAINTAINERS: remove include/linux/of_pwm.h
  MAINTAINERS: remove arch/*/lib/perf_event*.c
  MAINTAINERS: remove drivers/mmc/host/imxmmc.*
  MAINTAINERS: fix Documentation/mei/
  MAINTAINERS: remove arch/x86/platform/mrst/pmu.*
  MAINTAINERS: remove firmware/isci/
  MAINTAINERS: fix drivers/ieee802154/
  MAINTAINERS: fix .../plat-mxc/include/mach/imxfb.h
  MAINTAINERS: remove drivers/video/epson1355fb.c
  MAINTAINERS: fix drivers/media/usb/dvb-usb/cxusb*
  MAINTAINERS: adjust for UAPI
  MAINTAINERS: fix drivers/media/platform/atmel-isi.c
  MAINTAINERS: fix arch/arm/mach-at91/include/mach/at_hdmac.h
  MAINTAINERS: fix drivers/rtc/rtc-vt8500.c
  MAINTAINERS: remove arch/arm/plat-s5p/
  ...

Documentation/sysctl/kernel.txt

@@ -38,6 +38,7 @@ show up in /proc/sys/kernel:
 - l2cr                        [ PPC only ]
 - modprobe                    ==> Documentation/debugging-modules.txt
 - modules_disabled
+- msg_next_id		      [ sysv ipc ]
 - msgmax
 - msgmnb
 - msgmni
@@ -62,7 +63,9 @@ show up in /proc/sys/kernel:
 - rtsig-max
 - rtsig-nr
 - sem
+- sem_next_id		      [ sysv ipc ]
 - sg-big-buff                 [ generic SCSI device (sg) ]
+- shm_next_id		      [ sysv ipc ]
 - shm_rmid_forced
 - shmall
 - shmmax                      [ sysv ipc ]
@@ -320,6 +323,22 @@ to false.
 
 ==============================================================
 
+msg_next_id, sem_next_id, and shm_next_id:
+
+These three toggles allows to specify desired id for next allocated IPC
+object: message, semaphore or shared memory respectively.
+
+By default they are equal to -1, which means generic allocation logic.
+Possible values to set are in range {0..INT_MAX}.
+
+Notes:
+1) kernel doesn't guarantee, that new object will have desired id. So,
+it's up to userspace, how to handle an object with "wrong" id.
+2) Toggle with non-default value will be set back to -1 by kernel after
+successful IPC object allocation.
+
+==============================================================
+
 nmi_watchdog:
 
 Enables/Disables the NMI watchdog on x86 systems. When the value is
@@ -542,6 +561,19 @@ are doing anyway :)
 
 ==============================================================
 
+shmall:
+
+This parameter sets the total amount of shared memory pages that
+can be used system wide. Hence, SHMALL should always be at least
+ceil(shmmax/PAGE_SIZE).
+
+If you are not sure what the default PAGE_SIZE is on your Linux
+system, you can run the following command:
+
+# getconf PAGE_SIZE
+
+==============================================================
+
 shmmax:
 
 This value can be used to query and set the run time limit

drivers/rtc/Kconfig

@@ -352,6 +352,14 @@ config RTC_DRV_TWL4030
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-twl.
 
+config RTC_DRV_TPS6586X
+	tristate "TI TPS6586X RTC driver"
+	depends on MFD_TPS6586X
+	help
+	  TI Power Managment IC TPS6586X supports RTC functionality
+	  along with alarm. This driver supports the RTC driver for
+	  the TPS6586X RTC module.
+
 config RTC_DRV_TPS65910
 	tristate "TI TPS65910 RTC driver"
 	depends on RTC_CLASS && MFD_TPS65910

drivers/rtc/Makefile

@@ -111,6 +111,7 @@ obj-$(CONFIG_RTC_DRV_TEGRA)	+= rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_TILE)	+= rtc-tile.o
 obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl.o
+obj-$(CONFIG_RTC_DRV_TPS6586X)	+= rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TPS65910)	+= rtc-tps65910.o
 obj-$(CONFIG_RTC_DRV_TX4939)	+= rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o

drivers/rtc/rtc-tegra.c

@@ -303,6 +303,12 @@ static struct rtc_class_ops tegra_rtc_ops = {
 	.alarm_irq_enable = tegra_rtc_alarm_irq_enable,
 };
 
+static const struct of_device_id tegra_rtc_dt_match[] = {
+	{ .compatible = "nvidia,tegra20-rtc", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, tegra_rtc_dt_match);
+
 static int tegra_rtc_probe(struct platform_device *pdev)
 {
 	struct tegra_rtc_info *info;
@@ -440,6 +446,7 @@ static struct platform_driver tegra_rtc_driver = {
 	.driver		= {
 		.name	= "tegra_rtc",
 		.owner	= THIS_MODULE,
+		.of_match_table = tegra_rtc_dt_match,
 	},
 #ifdef CONFIG_PM
 	.suspend	= tegra_rtc_suspend,

drivers/rtc/rtc-tps6586x.c

+/*
+ * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X
+ *
+ * Copyright (c) 2012, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/tps6586x.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define RTC_CTRL			0xc0
+#define POR_RESET_N			BIT(7)
+#define OSC_SRC_SEL			BIT(6)
+#define RTC_ENABLE			BIT(5)	/* enables alarm */
+#define RTC_BUF_ENABLE			BIT(4)	/* 32 KHz buffer enable */
+#define PRE_BYPASS			BIT(3)	/* 0=1KHz or 1=32KHz updates */
+#define CL_SEL_MASK			(BIT(2)|BIT(1))
+#define CL_SEL_POS			1
+#define RTC_ALARM1_HI			0xc1
+#define RTC_COUNT4			0xc6
+
+/* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
+#define RTC_COUNT4_DUMMYREAD		0xc5
+
+/*only 14-bits width in second*/
+#define ALM1_VALID_RANGE_IN_SEC		0x3FFF
+
+#define TPS6586X_RTC_CL_SEL_1_5PF	0x0
+#define TPS6586X_RTC_CL_SEL_6_5PF	0x1
+#define TPS6586X_RTC_CL_SEL_7_5PF	0x2
+#define TPS6586X_RTC_CL_SEL_12_5PF	0x3
+
+struct tps6586x_rtc {
+	struct device		*dev;
+	struct rtc_device	*rtc;
+	int			irq;
+	bool			irq_en;
+	unsigned long long	epoch_start;
+};
+
+static inline struct device *to_tps6586x_dev(struct device *dev)
+{
+	return dev->parent;
+}
+
+static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+	struct device *tps_dev = to_tps6586x_dev(dev);
+	unsigned long long ticks = 0;
+	unsigned long seconds;
+	u8 buff[6];
+	int ret;
+	int i;
+
+	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
+	if (ret < 0) {
+		dev_err(dev, "read counter failed with err %d\n", ret);
+		return ret;
+	}
+
+	for (i = 1; i < sizeof(buff); i++) {
+		ticks <<= 8;
+		ticks |= buff[i];
+	}
+
+	seconds = ticks >> 10;
+	seconds += rtc->epoch_start;
+	rtc_time_to_tm(seconds, tm);
+	return rtc_valid_tm(tm);
+}
+
+static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+	struct device *tps_dev = to_tps6586x_dev(dev);
+	unsigned long long ticks;
+	unsigned long seconds;
+	u8 buff[5];
+	int ret;
+
+	rtc_tm_to_time(tm, &seconds);
+	if (seconds < rtc->epoch_start) {
+		dev_err(dev, "requested time unsupported\n");
+		return -EINVAL;
+	}
+	seconds -= rtc->epoch_start;
+
+	ticks = (unsigned long long)seconds << 10;
+	buff[0] = (ticks >> 32) & 0xff;
+	buff[1] = (ticks >> 24) & 0xff;
+	buff[2] = (ticks >> 16) & 0xff;
+	buff[3] = (ticks >> 8) & 0xff;
+	buff[4] = ticks & 0xff;
+
+	/* Disable RTC before changing time */
+	ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
+	if (ret < 0) {
+		dev_err(dev, "failed to clear RTC_ENABLE\n");
+		return ret;
+	}
+
+	ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
+	if (ret < 0) {
+		dev_err(dev, "failed to program new time\n");
+		return ret;
+	}
+
+	/* Enable RTC */
+	ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
+	if (ret < 0) {
+		dev_err(dev, "failed to set RTC_ENABLE\n");
+		return ret;
+	}
+	return 0;
+}
+
+static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
+			 unsigned int enabled)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+
+	if (enabled && !rtc->irq_en) {
+		enable_irq(rtc->irq);
+		rtc->irq_en = true;
+	} else if (!enabled && rtc->irq_en)  {
+		disable_irq(rtc->irq);
+		rtc->irq_en = false;
+	}
+	return 0;
+}
+
+static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+	struct device *tps_dev = to_tps6586x_dev(dev);
+	unsigned long seconds;
+	unsigned long ticks;
+	unsigned long rtc_current_time;
+	unsigned long long rticks = 0;
+	u8 buff[3];
+	u8 rbuff[6];
+	int ret;
+	int i;
+
+	rtc_tm_to_time(&alrm->time, &seconds);
+
+	if (alrm->enabled && (seconds < rtc->epoch_start)) {
+		dev_err(dev, "can't set alarm to requested time\n");
+		return -EINVAL;
+	}
+
+	ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled);
+	if (ret < 0) {
+		dev_err(dev, "can't set alarm irq, err %d\n", ret);
+		return ret;
+	}
+
+	seconds -= rtc->epoch_start;
+	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD,
+			sizeof(rbuff), rbuff);
+	if (ret < 0) {
+		dev_err(dev, "read counter failed with err %d\n", ret);
+		return ret;
+	}
+
+	for (i = 1; i < sizeof(rbuff); i++) {
+		rticks <<= 8;
+		rticks |= rbuff[i];
+	}
+
+	rtc_current_time = rticks >> 10;
+	if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
+		seconds = rtc_current_time - 1;
+
+	ticks = (unsigned long long)seconds << 10;
+	buff[0] = (ticks >> 16) & 0xff;
+	buff[1] = (ticks >> 8) & 0xff;
+	buff[2] = ticks & 0xff;
+
+	ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
+	if (ret)
+		dev_err(dev, "programming alarm failed with err %d\n", ret);
+
+	return ret;
+}
+
+static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+	struct device *tps_dev = to_tps6586x_dev(dev);
+	unsigned long ticks;
+	unsigned long seconds;
+	u8 buff[3];
+	int ret;
+
+	ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
+	if (ret) {
+		dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret);
+		return ret;
+	}
+
+	ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2];
+	seconds = ticks >> 10;
+	seconds += rtc->epoch_start;
+
+	rtc_time_to_tm(seconds, &alrm->time);
+	return 0;
+}
+
+static const struct rtc_class_ops tps6586x_rtc_ops = {
+	.read_time	= tps6586x_rtc_read_time,
+	.set_time	= tps6586x_rtc_set_time,
+	.set_alarm	= tps6586x_rtc_set_alarm,
+	.read_alarm	= tps6586x_rtc_read_alarm,
+	.alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
+{
+	struct tps6586x_rtc *rtc = data;
+
+	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+	return IRQ_HANDLED;
+}
+
+static int tps6586x_rtc_probe(struct platform_device *pdev)
+{
+	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
+	struct tps6586x_rtc *rtc;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->dev = &pdev->dev;
+	rtc->irq = platform_get_irq(pdev, 0);
+
+	/* Set epoch start as 00:00:00:01:01:2009 */
+	rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0);
+
+	/* 1 kHz tick mode, enable tick counting */
+	ret = tps6586x_update(tps_dev, RTC_CTRL,
+		RTC_ENABLE | OSC_SRC_SEL |
+		((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK),
+		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to start counter\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, rtc);
+	rtc->rtc = rtc_device_register(dev_name(&pdev->dev), &pdev->dev,
+				       &tps6586x_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc->rtc)) {
+		ret = PTR_ERR(rtc->rtc);
+		dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
+		goto fail_rtc_register;
+	}
+
+	ret = request_threaded_irq(rtc->irq, NULL, tps6586x_rtc_irq,
+				IRQF_ONESHOT | IRQF_EARLY_RESUME,
+				dev_name(&pdev->dev), rtc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n",
+				rtc->irq, ret);
+		goto fail_req_irq;
+	}
+	disable_irq(rtc->irq);
+	device_set_wakeup_capable(&pdev->dev, 1);
+	return 0;
+
+fail_req_irq:
+	rtc_device_unregister(rtc->rtc);
+
+fail_rtc_register:
+	tps6586x_update(tps_dev, RTC_CTRL, 0,
+		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
+	return ret;
+};
+
+static int tps6586x_rtc_remove(struct platform_device *pdev)
+{
+	struct tps6586x_rtc *rtc = platform_get_drvdata(pdev);
+	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
+
+	tps6586x_update(tps_dev, RTC_CTRL, 0,
+		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
+	rtc_device_unregister(rtc->rtc);
+	free_irq(rtc->irq, rtc);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tps6586x_rtc_suspend(struct device *dev)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(rtc->irq);
+	return 0;
+}
+
+static int tps6586x_rtc_resume(struct device *dev)
+{
+	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(rtc->irq);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops tps6586x_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tps6586x_rtc_suspend, tps6586x_rtc_resume)
+};
+
+static struct platform_driver tps6586x_rtc_driver = {
+	.driver	= {
+		.name	= "tps6586x-rtc",
+		.owner	= THIS_MODULE,
+		.pm	= &tps6586x_pm_ops,
+	},
+	.probe	= tps6586x_rtc_probe,
+	.remove	= tps6586x_rtc_remove,
+};
+module_platform_driver(tps6586x_rtc_driver);
+
+MODULE_ALIAS("platform:rtc-tps6586x");
+MODULE_DESCRIPTION("TI TPS6586x RTC driver");
+MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL v2");

drivers/rtc/rtc-vt8500.c

@@ -70,7 +70,7 @@
 				| ALARM_SEC_BIT)
 
 #define VT8500_RTC_CR_ENABLE	(1 << 0)	/* Enable RTC */
-#define VT8500_RTC_CR_24H	(1 << 1)	/* 24h time format */
+#define VT8500_RTC_CR_12H	(1 << 1)	/* 12h time format */
 #define VT8500_RTC_CR_SM_ENABLE	(1 << 2)	/* Enable periodic irqs */
 #define VT8500_RTC_CR_SM_SEC	(1 << 3)	/* 0: 1Hz/60, 1: 1Hz */
 #define VT8500_RTC_CR_CALIB	(1 << 4)	/* Enable calibration */
@@ -119,7 +119,7 @@ static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
 	tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
 	tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
-	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
+	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
 	tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
 			+ ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
 	tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
@@ -138,8 +138,9 @@ static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	}
 
 	writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
-		| (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
-		| (bin2bcd(tm->tm_mday)),
+		| (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
+		| (bin2bcd(tm->tm_mday))
+		| ((tm->tm_year >= 200) << DATE_CENTURY_S),
 		vt8500_rtc->regbase + VT8500_RTC_DS);
 	writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
 		| (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
@@ -247,7 +248,7 @@ static int vt8500_rtc_probe(struct platform_device *pdev)
 	}
 
 	/* Enable RTC and set it to 24-hour mode */
-	writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H,
+	writel(VT8500_RTC_CR_ENABLE,
 	       vt8500_rtc->regbase + VT8500_RTC_CR);
 
 	vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,

include/asm-generic/tlb.h

@@ -78,6 +78,14 @@ struct mmu_gather_batch {
 #define MAX_GATHER_BATCH	\
 	((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))
 
+/*
+ * Limit the maximum number of mmu_gather batches to reduce a risk of soft
+ * lockups for non-preemptible kernels on huge machines when a lot of memory
+ * is zapped during unmapping.
+ * 10K pages freed at once should be safe even without a preemption point.
+ */
+#define MAX_GATHER_BATCH_COUNT	(10000UL/MAX_GATHER_BATCH)
+
 /* struct mmu_gather is an opaque type used by the mm code for passing around
  * any data needed by arch specific code for tlb_remove_page.
  */
@@ -96,6 +104,7 @@ struct mmu_gather {
 	struct mmu_gather_batch *active;
 	struct mmu_gather_batch	local;
 	struct page		*__pages[MMU_GATHER_BUNDLE];
+	unsigned int		batch_count;
 };
 
 #define HAVE_GENERIC_MMU_GATHER

include/linux/ipc_namespace.h

@@ -24,6 +24,7 @@ struct ipc_ids {
 	unsigned short seq_max;
 	struct rw_semaphore rw_mutex;
 	struct idr ipcs_idr;
+	int next_id;
 };
 
 struct ipc_namespace {

include/linux/mmzone.h

@@ -503,14 +503,6 @@ struct zone {
 	 * rarely used fields:
 	 */
 	const char		*name;
-#ifdef CONFIG_MEMORY_ISOLATION
-	/*
-	 * the number of MIGRATE_ISOLATE *pageblock*.
-	 * We need this for free page counting. Look at zone_watermark_ok_safe.
-	 * It's protected by zone->lock
-	 */
-	int		nr_pageblock_isolate;
-#endif
 } ____cacheline_internodealigned_in_smp;
 
 typedef enum {

include/linux/msg.h

@@ -34,7 +34,9 @@ struct msg_queue {
 /* Helper routines for sys_msgsnd and sys_msgrcv */
 extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
 			size_t msgsz, int msgflg);
-extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
-			size_t msgsz, long msgtyp, int msgflg);
+extern long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
+		      int msgflg,
+		      long (*msg_fill)(void __user *, struct msg_msg *,
+				       size_t));
 
 #endif /* _LINUX_MSG_H */

include/uapi/linux/msg.h

@@ -10,6 +10,7 @@
 /* msgrcv options */
 #define MSG_NOERROR     010000  /* no error if message is too big */
 #define MSG_EXCEPT      020000  /* recv any msg except of specified type.*/
+#define MSG_COPY        040000  /* copy (not remove) all queue messages */
 
 /* Obsolete, used only for backwards compatibility and libc5 compiles */
 struct msqid_ds {

ipc/compat.c

@@ -306,6 +306,20 @@ static long do_compat_semctl(int first, int second, int third, u32 pad)
 	return err;
 }
 
+long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+	struct compat_msgbuf __user *msgp = dest;
+	size_t msgsz;
+
+	if (put_user(msg->m_type, &msgp->mtype))
+		return -EFAULT;
+
+	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+	if (store_msg(msgp->mtext, msg, msgsz))
+		return -EFAULT;
+	return msgsz;
+}
+
 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
 long compat_sys_semctl(int first, int second, int third, void __user *uptr)
 {
@@ -337,10 +351,6 @@ long compat_sys_msgsnd(int first, int second, int third, void __user *uptr)
 long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
 			   int version, void __user *uptr)
 {
-	struct compat_msgbuf __user *up;
-	long type;
-	int err;
-
 	if (first < 0)
 		return -EINVAL;
 	if (second < 0)
@@ -348,23 +358,15 @@ long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
 
 	if (!version) {
 		struct compat_ipc_kludge ipck;
-		err = -EINVAL;
 		if (!uptr)
-			goto out;
-		err = -EFAULT;
+			return -EINVAL;
 		if (copy_from_user (&ipck, uptr, sizeof(ipck)))
-			goto out;
+			return -EFAULT;
 		uptr = compat_ptr(ipck.msgp);
 		msgtyp = ipck.msgtyp;
 	}
-	up = uptr;
-	err = do_msgrcv(first, &type, up->mtext, second, msgtyp, third);
-	if (err < 0)
-		goto out;
-	if (put_user(type, &up->mtype))
-		err = -EFAULT;
-out:
-	return err;
+	return do_msgrcv(first, uptr, second, msgtyp, third,
+			 compat_do_msg_fill);
 }
 #else
 long compat_sys_semctl(int semid, int semnum, int cmd, int arg)
@@ -385,16 +387,8 @@ long compat_sys_msgsnd(int msqid, struct compat_msgbuf __user *msgp,
 long compat_sys_msgrcv(int msqid, struct compat_msgbuf __user *msgp,
 		       compat_ssize_t msgsz, long msgtyp, int msgflg)
 {
-	long err, mtype;
-
-	err =  do_msgrcv(msqid, &mtype, msgp->mtext, (ssize_t)msgsz, msgtyp, msgflg);
-	if (err < 0)
-		goto out;
-
-	if (put_user(mtype, &msgp->mtype))
-		err = -EFAULT;
- out:
-	return err;
+	return do_msgrcv(msqid, msgp, (ssize_t)msgsz, msgtyp, msgflg,
+			 compat_do_msg_fill);
 }
 #endif
 

ipc/ipc_sysctl.c

@@ -158,6 +158,9 @@ static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
 
 static int zero;
 static int one = 1;
+#ifdef CONFIG_CHECKPOINT_RESTORE
+static int int_max = INT_MAX;
+#endif
 
 static struct ctl_table ipc_kern_table[] = {
 	{
@@ -227,6 +230,35 @@ static struct ctl_table ipc_kern_table[] = {
 		.extra1		= &zero,
 		.extra2		= &one,
 	},
+#ifdef CONFIG_CHECKPOINT_RESTORE
+	{
+		.procname	= "sem_next_id",
+		.data		= &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
+		.maxlen		= sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
+		.mode		= 0644,
+		.proc_handler	= proc_ipc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &int_max,
+	},
+	{
+		.procname	= "msg_next_id",
+		.data		= &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
+		.maxlen		= sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
+		.mode		= 0644,
+		.proc_handler	= proc_ipc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &int_max,
+	},
+	{
+		.procname	= "shm_next_id",
+		.data		= &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
+		.maxlen		= sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
+		.mode		= 0644,
+		.proc_handler	= proc_ipc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &int_max,
+	},
+#endif
 	{}
 };
 

ipc/msg.c

@@ -755,26 +755,91 @@ static inline int convert_mode(long *msgtyp, int msgflg)
 	return SEARCH_EQUAL;
 }
 
-long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
-		size_t msgsz, long msgtyp, int msgflg)
+static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+	struct msgbuf __user *msgp = dest;
+	size_t msgsz;
+
+	if (put_user(msg->m_type, &msgp->mtype))
+		return -EFAULT;
+
+	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+	if (store_msg(msgp->mtext, msg, msgsz))
+		return -EFAULT;
+	return msgsz;
+}
+
+#ifdef CONFIG_CHECKPOINT_RESTORE
+/*
+ * This function creates new kernel message structure, large enough to store
+ * bufsz message bytes.
+ */
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
+					   int msgflg, long *msgtyp,
+					   unsigned long *copy_number)
+{
+	struct msg_msg *copy;
+
+	*copy_number = *msgtyp;
+	*msgtyp = 0;
+	/*
+	 * Create dummy message to copy real message to.
+	 */
+	copy = load_msg(buf, bufsz);
+	if (!IS_ERR(copy))
+		copy->m_ts = bufsz;
+	return copy;
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+	if (copy)
+		free_msg(copy);
+}
+#else
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
+					   int msgflg, long *msgtyp,
+					   unsigned long *copy_number)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline void free_copy(struct msg_msg *copy)
+{
+}
+#endif
+
+long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
+	       int msgflg,
+	       long (*msg_handler)(void __user *, struct msg_msg *, size_t))
 {
 	struct msg_queue *msq;
 	struct msg_msg *msg;
 	int mode;
 	struct ipc_namespace *ns;
+	struct msg_msg *copy = NULL;
+	unsigned long copy_number = 0;
 
-	if (msqid < 0 || (long) msgsz < 0)
+	if (msqid < 0 || (long) bufsz < 0)
 		return -EINVAL;
+	if (msgflg & MSG_COPY) {
+		copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, &copy_number);
+		if (IS_ERR(copy))
+			return PTR_ERR(copy);
+	}
 	mode = convert_mode(&msgtyp, msgflg);
 	ns = current->nsproxy->ipc_ns;
 
 	msq = msg_lock_check(ns, msqid);
-	if (IS_ERR(msq))
+	if (IS_ERR(msq)) {
+		free_copy(copy);
 		return PTR_ERR(msq);
+	}
 
 	for (;;) {
 		struct msg_receiver msr_d;
 		struct list_head *tmp;
+		long msg_counter = 0;
 
 		msg = ERR_PTR(-EACCES);
 		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
@@ -793,12 +858,21 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
 				msg = walk_msg;
 				if (mode == SEARCH_LESSEQUAL &&
 						walk_msg->m_type != 1) {
-					msg = walk_msg;
 					msgtyp = walk_msg->m_type - 1;
-				} else {
-					msg = walk_msg;
+				} else if (msgflg & MSG_COPY) {
+					if (copy_number == msg_counter) {
+						/*
+						 * Found requested message.
+						 * Copy it.
+						 */
+						msg = copy_msg(msg, copy);
+						if (IS_ERR(msg))
+							goto out_unlock;
+						break;
+					}
+				} else
 					break;
-				}
+				msg_counter++;
 			}
 			tmp = tmp->next;
 		}
@@ -807,10 +881,16 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
 			 * Found a suitable message.
 			 * Unlink it from the queue.
 			 */
-			if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+			if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
 				msg = ERR_PTR(-E2BIG);
 				goto out_unlock;
 			}
+			/*
+			 * If we are copying, then do not unlink message and do
+			 * not update queue parameters.
+			 */
+			if (msgflg & MSG_COPY)
+				goto out_unlock;
 			list_del(&msg->m_list);
 			msq->q_qnum--;
 			msq->q_rtime = get_seconds();
@@ -834,7 +914,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
 		if (msgflg & MSG_NOERROR)
 			msr_d.r_maxsize = INT_MAX;
 		else
-			msr_d.r_maxsize = msgsz;
+			msr_d.r_maxsize = bufsz;
 		msr_d.r_msg = ERR_PTR(-EAGAIN);
 		current->state = TASK_INTERRUPTIBLE;
 		msg_unlock(msq);
@@ -894,32 +974,21 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
 			break;
 		}
 	}
-	if (IS_ERR(msg))
+	if (IS_ERR(msg)) {
+		free_copy(copy);
 		return PTR_ERR(msg);
+	}
 
-	msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz;
-	*pmtype = msg->m_type;
-	if (store_msg(mtext, msg, msgsz))
-		msgsz = -EFAULT;
-
+	bufsz = msg_handler(buf, msg, bufsz);
 	free_msg(msg);
 
-	return msgsz;
+	return bufsz;
 }
 
 SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
 		long, msgtyp, int, msgflg)
 {
-	long err, mtype;
-
-	err =  do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
-	if (err < 0)
-		goto out;
-
-	if (put_user(mtype, &msgp->mtype))
-		err = -EFAULT;
-out:
-	return err;
+	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
 }
 
 #ifdef CONFIG_PROC_FS

ipc/msgutil.c

@@ -102,7 +102,50 @@ struct msg_msg *load_msg(const void __user *src, int len)
 	free_msg(msg);
 	return ERR_PTR(err);
 }
+#ifdef CONFIG_CHECKPOINT_RESTORE
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+	struct msg_msgseg *dst_pseg, *src_pseg;
+	int len = src->m_ts;
+	int alen;
+
+	BUG_ON(dst == NULL);
+	if (src->m_ts > dst->m_ts)
+		return ERR_PTR(-EINVAL);
 
+	alen = len;
+	if (alen > DATALEN_MSG)
+		alen = DATALEN_MSG;
+
+	dst->next = NULL;
+	dst->security = NULL;
+
+	memcpy(dst + 1, src + 1, alen);
+
+	len -= alen;
+	dst_pseg = dst->next;
+	src_pseg = src->next;
+	while (len > 0) {
+		alen = len;
+		if (alen > DATALEN_SEG)
+			alen = DATALEN_SEG;
+		memcpy(dst_pseg + 1, src_pseg + 1, alen);
+		dst_pseg = dst_pseg->next;
+		len -= alen;
+		src_pseg = src_pseg->next;
+	}
+
+	dst->m_type = src->m_type;
+	dst->m_ts = src->m_ts;
+
+	return dst;
+}
+#else
+struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
+{
+	return ERR_PTR(-ENOSYS);
+}
+#endif
 int store_msg(void __user *dest, struct msg_msg *msg, int len)
 {
 	int alen;

ipc/util.c

@@ -122,6 +122,7 @@ void ipc_init_ids(struct ipc_ids *ids)
 
 	ids->in_use = 0;
 	ids->seq = 0;
+	ids->next_id = -1;
 	{
 		int seq_limit = INT_MAX/SEQ_MULTIPLIER;
 		if (seq_limit > USHRT_MAX)
@@ -252,6 +253,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	kuid_t euid;
 	kgid_t egid;
 	int id, err;
+	int next_id = ids->next_id;
 
 	if (size > IPCMNI)
 		size = IPCMNI;
@@ -264,7 +266,8 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	rcu_read_lock();
 	spin_lock(&new->lock);
 
-	err = idr_get_new(&ids->ipcs_idr, new, &id);
+	err = idr_get_new_above(&ids->ipcs_idr, new,
+				(next_id < 0) ? 0 : ipcid_to_idx(next_id), &id);
 	if (err) {
 		spin_unlock(&new->lock);
 		rcu_read_unlock();
@@ -277,9 +280,14 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	new->cuid = new->uid = euid;
 	new->gid = new->cgid = egid;
 
-	new->seq = ids->seq++;
-	if(ids->seq > ids->seq_max)
-		ids->seq = 0;
+	if (next_id < 0) {
+		new->seq = ids->seq++;
+		if (ids->seq > ids->seq_max)
+			ids->seq = 0;
+	} else {
+		new->seq = ipcid_to_seqx(next_id);
+		ids->next_id = -1;
+	}
 
 	new->id = ipc_buildid(id, new->seq);
 	return id;

ipc/util.h

@@ -92,6 +92,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
 #define IPC_SHM_IDS	2
 
 #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
+#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
 
 /* must be called with ids->rw_mutex acquired for writing */
 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
@@ -139,6 +140,7 @@ int ipc_parse_version (int *cmd);
 
 extern void free_msg(struct msg_msg *msg);
 extern struct msg_msg *load_msg(const void __user *src, int len);
+extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
 
 extern void recompute_msgmni(struct ipc_namespace *);

kernel/printk.c

@@ -870,10 +870,11 @@ static size_t print_time(u64 ts, char *buf)
 	if (!printk_time)
 		return 0;
 
+	rem_nsec = do_div(ts, 1000000000);
+
 	if (!buf)
-		return 15;
+		return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts);
 
-	rem_nsec = do_div(ts, 1000000000);
 	return sprintf(buf, "[%5lu.%06lu] ",
 		       (unsigned long)ts, rem_nsec / 1000);
 }

mm/memory.c

@@ -184,10 +184,14 @@ static int tlb_next_batch(struct mmu_gather *tlb)
 		return 1;
 	}
 
+	if (tlb->batch_count == MAX_GATHER_BATCH_COUNT)
+		return 0;
+
 	batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
 	if (!batch)
 		return 0;
 
+	tlb->batch_count++;
 	batch->next = NULL;
 	batch->nr   = 0;
 	batch->max  = MAX_GATHER_BATCH;
@@ -216,6 +220,7 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm)
 	tlb->local.nr   = 0;
 	tlb->local.max  = ARRAY_SIZE(tlb->__pages);
 	tlb->active     = &tlb->local;
+	tlb->batch_count = 0;
 
 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
 	tlb->batch = NULL;

mm/page_alloc.c

@@ -221,11 +221,6 @@ EXPORT_SYMBOL(nr_online_nodes);
 
 int page_group_by_mobility_disabled __read_mostly;
 
-/*
- * NOTE:
- * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
- * Instead, use {un}set_pageblock_isolate.
- */
 void set_pageblock_migratetype(struct page *page, int migratetype)
 {
 
@@ -1655,20 +1650,6 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 	return true;
 }
 
-#ifdef CONFIG_MEMORY_ISOLATION
-static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
-{
-	if (unlikely(zone->nr_pageblock_isolate))
-		return zone->nr_pageblock_isolate * pageblock_nr_pages;
-	return 0;
-}
-#else
-static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
-{
-	return 0;
-}
-#endif
-
 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 		      int classzone_idx, int alloc_flags)
 {
@@ -1684,14 +1665,6 @@ bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
 	if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
 		free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
 
-	/*
-	 * If the zone has MIGRATE_ISOLATE type free pages, we should consider
-	 * it.  nr_zone_isolate_freepages is never accurate so kswapd might not
-	 * sleep although it could do so.  But this is more desirable for memory
-	 * hotplug than sleeping which can cause a livelock in the direct
-	 * reclaim path.
-	 */
-	free_pages -= nr_zone_isolate_freepages(z);
 	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
 								free_pages);
 }

mm/page_isolation.c

@@ -8,28 +8,6 @@
 #include <linux/memory.h>
 #include "internal.h"
 
-/* called while holding zone->lock */
-static void set_pageblock_isolate(struct page *page)
-{
-	if (get_pageblock_migratetype(page) == MIGRATE_ISOLATE)
-		return;
-
-	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
-	page_zone(page)->nr_pageblock_isolate++;
-}
-
-/* called while holding zone->lock */
-static void restore_pageblock_isolate(struct page *page, int migratetype)
-{
-	struct zone *zone = page_zone(page);
-	if (WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE))
-		return;
-
-	BUG_ON(zone->nr_pageblock_isolate <= 0);
-	set_pageblock_migratetype(page, migratetype);
-	zone->nr_pageblock_isolate--;
-}
-
 int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages)
 {
 	struct zone *zone;
@@ -80,7 +58,7 @@ int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages)
 		unsigned long nr_pages;
 		int migratetype = get_pageblock_migratetype(page);
 
-		set_pageblock_isolate(page);
+		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
 		nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
 
 		__mod_zone_freepage_state(zone, -nr_pages, migratetype);
@@ -103,7 +81,7 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 		goto out;
 	nr_pages = move_freepages_block(zone, page, migratetype);
 	__mod_zone_freepage_state(zone, nr_pages, migratetype);
-	restore_pageblock_isolate(page, migratetype);
+	set_pageblock_migratetype(page, migratetype);
 out:
 	spin_unlock_irqrestore(&zone->lock, flags);
 }

tools/testing/selftests/ipc/Makefile

+uname_M := $(shell uname -m 2>/dev/null || echo not)
+ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/)
+ifeq ($(ARCH),i386)
+        ARCH := X86
+	CFLAGS := -DCONFIG_X86_32 -D__i386__
+endif
+ifeq ($(ARCH),x86_64)
+	ARCH := X86
+	CFLAGS := -DCONFIG_X86_64 -D__x86_64__
+endif
+
+CFLAGS += -I../../../../usr/include/
+
+all:
+ifeq ($(ARCH),X86)
+	gcc $(CFLAGS) msgque.c -o msgque_test
+else
+	echo "Not an x86 target, can't build msgque selftest"
+endif
+
+run_tests: all
+	./msgque_test
+
+clean:
+	rm -fr ./msgque_test

tools/testing/selftests/ipc/msgque.c

+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <linux/msg.h>
+#include <fcntl.h>
+
+#define MAX_MSG_SIZE		32
+
+struct msg1 {
+	int msize;
+	long mtype;
+	char mtext[MAX_MSG_SIZE];
+};
+
+#define TEST_STRING "Test sysv5 msg"
+#define MSG_TYPE 1
+
+#define ANOTHER_TEST_STRING "Yet another test sysv5 msg"
+#define ANOTHER_MSG_TYPE 26538
+
+struct msgque_data {
+	key_t key;
+	int msq_id;
+	int qbytes;
+	int qnum;
+	int mode;
+	struct msg1 *messages;
+};
+
+int restore_queue(struct msgque_data *msgque)
+{
+	int fd, ret, id, i;
+	char buf[32];
+
+	fd = open("/proc/sys/kernel/msg_next_id", O_WRONLY);
+	if (fd == -1) {
+		printf("Failed to open /proc/sys/kernel/msg_next_id\n");
+		return -errno;
+	}
+	sprintf(buf, "%d", msgque->msq_id);
+
+	ret = write(fd, buf, strlen(buf));
+	if (ret != strlen(buf)) {
+		printf("Failed to write to /proc/sys/kernel/msg_next_id\n");
+		return -errno;
+	}
+
+	id = msgget(msgque->key, msgque->mode | IPC_CREAT | IPC_EXCL);
+	if (id == -1) {
+		printf("Failed to create queue\n");
+		return -errno;
+	}
+
+	if (id != msgque->msq_id) {
+		printf("Restored queue has wrong id (%d instead of %d)\n",
+							id, msgque->msq_id);
+		ret = -EFAULT;
+		goto destroy;
+	}
+
+	for (i = 0; i < msgque->qnum; i++) {
+		if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype,
+			   msgque->messages[i].msize, IPC_NOWAIT) != 0) {
+			printf("msgsnd failed (%m)\n");
+			ret = -errno;
+			goto destroy;
+		};
+	}
+	return 0;
+
+destroy:
+	if (msgctl(id, IPC_RMID, 0))
+		printf("Failed to destroy queue: %d\n", -errno);
+	return ret;
+}
+
+int check_and_destroy_queue(struct msgque_data *msgque)
+{
+	struct msg1 message;
+	int cnt = 0, ret;
+
+	while (1) {
+		ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE,
+				0, IPC_NOWAIT);
+		if (ret < 0) {
+			if (errno == ENOMSG)
+				break;
+			printf("Failed to read IPC message: %m\n");
+			ret = -errno;
+			goto err;
+		}
+		if (ret != msgque->messages[cnt].msize) {
+			printf("Wrong message size: %d (expected %d)\n", ret,
+						msgque->messages[cnt].msize);
+			ret = -EINVAL;
+			goto err;
+		}
+		if (message.mtype != msgque->messages[cnt].mtype) {
+			printf("Wrong message type\n");
+			ret = -EINVAL;
+			goto err;
+		}
+		if (memcmp(message.mtext, msgque->messages[cnt].mtext, ret)) {
+			printf("Wrong message content\n");
+			ret = -EINVAL;
+			goto err;
+		}
+		cnt++;
+	}
+
+	if (cnt != msgque->qnum) {
+		printf("Wrong message number\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = 0;
+err:
+	if (msgctl(msgque->msq_id, IPC_RMID, 0)) {
+		printf("Failed to destroy queue: %d\n", -errno);
+		return -errno;
+	}
+	return ret;
+}
+
+int dump_queue(struct msgque_data *msgque)
+{
+	struct msqid64_ds ds;
+	int kern_id;
+	int i, ret;
+
+	for (kern_id = 0; kern_id < 256; kern_id++) {
+		ret = msgctl(kern_id, MSG_STAT, &ds);
+		if (ret < 0) {
+			if (errno == -EINVAL)
+				continue;
+			printf("Failed to get stats for IPC queue with id %d\n",
+					kern_id);
+			return -errno;
+		}
+
+		if (ret == msgque->msq_id)
+			break;
+	}
+
+	msgque->messages = malloc(sizeof(struct msg1) * ds.msg_qnum);
+	if (msgque->messages == NULL) {
+		printf("Failed to get stats for IPC queue\n");
+		return -ENOMEM;
+	}
+
+	msgque->qnum = ds.msg_qnum;
+	msgque->mode = ds.msg_perm.mode;
+	msgque->qbytes = ds.msg_qbytes;
+
+	for (i = 0; i < msgque->qnum; i++) {
+		ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype,
+				MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY);
+		if (ret < 0) {
+			printf("Failed to copy IPC message: %m (%d)\n", errno);
+			return -errno;
+		}
+		msgque->messages[i].msize = ret;
+	}
+	return 0;
+}
+
+int fill_msgque(struct msgque_data *msgque)
+{
+	struct msg1 msgbuf;
+
+	msgbuf.mtype = MSG_TYPE;
+	memcpy(msgbuf.mtext, TEST_STRING, sizeof(TEST_STRING));
+	if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING),
+				IPC_NOWAIT) != 0) {
+		printf("First message send failed (%m)\n");
+		return -errno;
+	};
+
+	msgbuf.mtype = ANOTHER_MSG_TYPE;
+	memcpy(msgbuf.mtext, ANOTHER_TEST_STRING, sizeof(ANOTHER_TEST_STRING));
+	if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING),
+				IPC_NOWAIT) != 0) {
+		printf("Second message send failed (%m)\n");
+		return -errno;
+	};
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int msg, pid, err;
+	struct msgque_data msgque;
+
+	msgque.key = ftok(argv[0], 822155650);
+	if (msgque.key == -1) {
+		printf("Can't make key\n");
+		return -errno;
+	}
+
+	msgque.msq_id = msgget(msgque.key, IPC_CREAT | IPC_EXCL | 0666);
+	if (msgque.msq_id == -1) {
+		printf("Can't create queue\n");
+		goto err_out;
+	}
+
+	err = fill_msgque(&msgque);
+	if (err) {
+		printf("Failed to fill queue\n");
+		goto err_destroy;
+	}
+
+	err = dump_queue(&msgque);
+	if (err) {
+		printf("Failed to dump queue\n");
+		goto err_destroy;
+	}
+
+	err = check_and_destroy_queue(&msgque);
+	if (err) {
+		printf("Failed to check and destroy queue\n");
+		goto err_out;
+	}
+
+	err = restore_queue(&msgque);
+	if (err) {
+		printf("Failed to restore queue\n");
+		goto err_destroy;
+	}
+
+	err = check_and_destroy_queue(&msgque);
+	if (err) {
+		printf("Failed to test queue\n");
+		goto err_out;
+	}
+	return 0;
+
+err_destroy:
+	if (msgctl(msgque.msq_id, IPC_RMID, 0)) {
+		printf("Failed to destroy queue: %d\n", -errno);
+		return -errno;
+	}
+err_out:
+	return err;
+}