From 655066c3835e7b51794c4d56f042eb78b5a79f53 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sun, 25 Jun 2006 05:48:17 -0700 Subject: [PATCH] RTC: rtc-dev UIE emulation Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with slight adjustments/refinements. This makes UIE-less rtc drivers work better with programs doing read/poll on /dev/rtc, such as hwclock. This emulation should not harm rtc drivers with UIE support, since rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first. Signed-off-by: Atsushi Nemoto Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-dev.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) (limited to 'drivers/rtc/rtc-dev.c') diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 2011567005f9..07387c99df0d 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -48,6 +48,93 @@ static int rtc_dev_open(struct inode *inode, struct file *file) return err; } +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL +/* + * Routine to poll RTC seconds field for change as often as possible, + * after first RTC_UIE use timer to reduce polling + */ +static void rtc_uie_task(void *data) +{ + struct rtc_device *rtc = data; + struct rtc_time tm; + int num = 0; + int err; + + err = rtc_read_time(&rtc->class_dev, &tm); + spin_lock_irq(&rtc->irq_lock); + if (rtc->stop_uie_polling || err) { + rtc->uie_task_active = 0; + } else if (rtc->oldsecs != tm.tm_sec) { + num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; + rtc->oldsecs = tm.tm_sec; + rtc->uie_timer.expires = jiffies + HZ - (HZ/10); + rtc->uie_timer_active = 1; + rtc->uie_task_active = 0; + add_timer(&rtc->uie_timer); + } else if (schedule_work(&rtc->uie_task) == 0) { + rtc->uie_task_active = 0; + } + spin_unlock_irq(&rtc->irq_lock); + if (num) + rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF); +} + +static void rtc_uie_timer(unsigned long data) +{ + struct rtc_device *rtc = (struct rtc_device *)data; + unsigned long flags; + + spin_lock_irqsave(&rtc->irq_lock, flags); + rtc->uie_timer_active = 0; + rtc->uie_task_active = 1; + if ((schedule_work(&rtc->uie_task) == 0)) + rtc->uie_task_active = 0; + spin_unlock_irqrestore(&rtc->irq_lock, flags); +} + +static void clear_uie(struct rtc_device *rtc) +{ + spin_lock_irq(&rtc->irq_lock); + if (rtc->irq_active) { + rtc->stop_uie_polling = 1; + if (rtc->uie_timer_active) { + spin_unlock_irq(&rtc->irq_lock); + del_timer_sync(&rtc->uie_timer); + spin_lock_irq(&rtc->irq_lock); + rtc->uie_timer_active = 0; + } + if (rtc->uie_task_active) { + spin_unlock_irq(&rtc->irq_lock); + flush_scheduled_work(); + spin_lock_irq(&rtc->irq_lock); + } + rtc->irq_active = 0; + } + spin_unlock_irq(&rtc->irq_lock); +} + +static int set_uie(struct rtc_device *rtc) +{ + struct rtc_time tm; + int err; + + err = rtc_read_time(&rtc->class_dev, &tm); + if (err) + return err; + spin_lock_irq(&rtc->irq_lock); + if (!rtc->irq_active) { + rtc->irq_active = 1; + rtc->stop_uie_polling = 0; + rtc->oldsecs = tm.tm_sec; + rtc->uie_task_active = 1; + if (schedule_work(&rtc->uie_task) == 0) + rtc->uie_task_active = 0; + } + rtc->irq_data = 0; + spin_unlock_irq(&rtc->irq_lock); + return 0; +} +#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ static ssize_t rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -232,6 +319,14 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, return -EFAULT; break; +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + case RTC_UIE_OFF: + clear_uie(rtc); + return 0; + + case RTC_UIE_ON: + return set_uie(rtc); +#endif default: err = -ENOTTY; break; @@ -244,6 +339,9 @@ static int rtc_dev_release(struct inode *inode, struct file *file) { struct rtc_device *rtc = to_rtc_device(file->private_data); +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + clear_uie(rtc); +#endif if (rtc->ops->release) rtc->ops->release(rtc->class_dev.dev); @@ -284,6 +382,10 @@ static int rtc_dev_add_device(struct class_device *class_dev, mutex_init(&rtc->char_lock); spin_lock_init(&rtc->irq_lock); init_waitqueue_head(&rtc->irq_queue); +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + INIT_WORK(&rtc->uie_task, rtc_uie_task, rtc); + setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); +#endif cdev_init(&rtc->char_dev, &rtc_dev_fops); rtc->char_dev.owner = rtc->owner; -- cgit v1.2.3 From 110d693d5898649da606cd6e5f6af4d7f70a405f Mon Sep 17 00:00:00 2001 From: Alessandro Zummo Date: Sun, 25 Jun 2006 05:48:20 -0700 Subject: [PATCH] rtc subsystem: add capability checks Centralize CAP_SYS_XXX checks to avoid duplicate code and missing checks in the drivers. Signed-off-by: Alessandro Zummo Cc: Richard Purdie Cc: Yoichi Yuasa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/class.c | 1 + drivers/rtc/rtc-dev.c | 29 ++++++++++++++++++++++------- drivers/rtc/rtc-sa1100.c | 4 ---- drivers/rtc/rtc-vr41xx.c | 8 -------- include/linux/rtc.h | 1 + 5 files changed, 24 insertions(+), 19 deletions(-) (limited to 'drivers/rtc/rtc-dev.c') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 413c7d54ea10..5396beec30d0 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -69,6 +69,7 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, rtc->id = id; rtc->ops = ops; rtc->owner = owner; + rtc->max_user_freq = 64; rtc->class_dev.dev = dev; rtc->class_dev.class = rtc_class; rtc->class_dev.release = rtc_device_release; diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 07387c99df0d..61a58259c93f 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -214,6 +214,28 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, struct rtc_wkalrm alarm; void __user *uarg = (void __user *) arg; + /* check that the calles has appropriate permissions + * for certain ioctls. doing this check here is useful + * to avoid duplicate code in each driver. + */ + switch (cmd) { + case RTC_EPOCH_SET: + case RTC_SET_TIME: + if (!capable(CAP_SYS_TIME)) + return -EACCES; + break; + + case RTC_IRQP_SET: + if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE)) + return -EACCES; + break; + + case RTC_PIE_ON: + if (!capable(CAP_SYS_RESOURCE)) + return -EACCES; + break; + } + /* avoid conflicting IRQ users */ if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) { spin_lock(&rtc->irq_task_lock); @@ -272,9 +294,6 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, break; case RTC_SET_TIME: - if (!capable(CAP_SYS_TIME)) - return -EACCES; - if (copy_from_user(&tm, uarg, sizeof(tm))) return -EFAULT; @@ -290,10 +309,6 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, err = -EINVAL; break; } - if (!capable(CAP_SYS_TIME)) { - err = -EACCES; - break; - } rtc_epoch = arg; err = 0; #endif diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c index a997529f8926..ab486fbc828d 100644 --- a/drivers/rtc/rtc-sa1100.c +++ b/drivers/rtc/rtc-sa1100.c @@ -229,8 +229,6 @@ static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd, spin_unlock_irq(&sa1100_rtc_lock); return 0; case RTC_PIE_ON: - if ((rtc_freq > 64) && !capable(CAP_SYS_RESOURCE)) - return -EACCES; spin_lock_irq(&sa1100_rtc_lock); OSMR1 = TIMER_FREQ/rtc_freq + OSCR; OIER |= OIER_E1; @@ -242,8 +240,6 @@ static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd, case RTC_IRQP_SET: if (arg < 1 || arg > TIMER_FREQ) return -EINVAL; - if ((arg > 64) && (!capable(CAP_SYS_RESOURCE))) - return -EACCES; rtc_freq = arg; return 0; } diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c index 277596c302e3..33e029207e26 100644 --- a/drivers/rtc/rtc-vr41xx.c +++ b/drivers/rtc/rtc-vr41xx.c @@ -81,7 +81,6 @@ MODULE_LICENSE("GPL"); #define RTC_FREQUENCY 32768 #define MAX_PERIODIC_RATE 6553 -#define MAX_USER_PERIODIC_RATE 64 static void __iomem *rtc1_base; static void __iomem *rtc2_base; @@ -240,9 +239,6 @@ static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long if (arg > MAX_PERIODIC_RATE) return -EINVAL; - if (arg > MAX_USER_PERIODIC_RATE && capable(CAP_SYS_RESOURCE) == 0) - return -EACCES; - periodic_frequency = arg; count = RTC_FREQUENCY; @@ -263,10 +259,6 @@ static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long /* Doesn't support before 1900 */ if (arg < 1900) return -EINVAL; - - if (capable(CAP_SYS_TIME) == 0) - return -EACCES; - epoch = arg; break; default: diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 43310760fe73..c12cbc1b83c5 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -155,6 +155,7 @@ struct rtc_device struct rtc_task *irq_task; spinlock_t irq_task_lock; int irq_freq; + int max_user_freq; #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL struct work_struct uie_task; struct timer_list uie_timer; -- cgit v1.2.3