Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int Presumably the (nid < 0) case has never happened. We do know that it is happening on one system while creating a symlink for a memory section so it should also happen on the same system if unregister_mem_sect_under_nodes() were called to remove the same symlink. The test was actually added in response to a problem with an earlier version reported by Yasunori Goto where one or more of the leading pages of a memory section on the 2nd node of one of his systems was uninitialized because I believe they coincided with a memory hole. That earlier version did not ignore uninitialized pages and determined the nid by considering only the 1st page of each memory section. This caused the symlink to the 1st memory section on the 2nd node to be incorrectly created in /sys/devices/system/node/node0 instead of /sys/devices/system/node/node1. The problem was fixed by adding the test to skip over uninitialized pages. I suspect we have not seen any reports of the non-removal of a symlink due to the incorrect declaration of the nid variable in unregister_mem_sect_under_nodes() because - systems where a memory section could have an uninitialized range of leading pages are probably rare. - memory remove is probably not done very frequently on the systems that are capable of demonstrating the problem. - lingering symlink(s) that should have been removed may have simply gone unnoticed. [garyhade@us.ibm.com: wrote changelog] Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1abaf33
genrtc.c
/*
* Real Time Clock interface for
* - q40 and other m68k machines,
* - HP PARISC machines
* - PowerPC machines
* emulate some RTC irq capabilities in software
*
* Copyright (C) 1999 Richard Zidlicky
*
* based on Paul Gortmaker's rtc.c device and
* Sam Creasey Generic rtc driver
*
* This driver allows use of the real time clock (built into
* nearly all computers) from user space. It exports the /dev/rtc
* interface supporting various ioctl() and also the /proc/driver/rtc
* pseudo-file for status information.
*
* The ioctls can be used to set the interrupt behaviour where
* supported.
*
* The /dev/rtc interface will block on reads until an interrupt
* has been received. If a RTC interrupt has already happened,
* it will output an unsigned long and then block. The output value
* contains the interrupt status in the low byte and the number of
* interrupts since the last read in the remaining high bytes. The
* /dev/rtc interface can also be used with the select(2) call.
*
* 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; either version
* 2 of the License, or (at your option) any later version.
*
* 1.01 fix for 2.3.X rz@linux-m68k.org
* 1.02 merged with code from genrtc.c rz@linux-m68k.org
* 1.03 make it more portable zippel@linux-m68k.org
* 1.04 removed useless timer code rz@linux-m68k.org
* 1.05 portable RTC_UIE emulation rz@linux-m68k.org
* 1.06 set_rtc_time can return an error trini@kernel.crashing.org
* 1.07 ported to HP PARISC (hppa) Helge Deller <deller@gmx.de>
*/
#define RTC_VERSION "1.07"
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/smp_lock.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/rtc.h>
/*
* We sponge a minor off of the misc major. No need slurping
* up another valuable major dev number for this. If you add
* an ioctl, make sure you don't conflict with SPARC's RTC
* ioctls.
*/
static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
/*
* Bits in gen_rtc_status.
*/
#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
static unsigned char gen_rtc_status; /* bitmapped status byte. */
static unsigned long gen_rtc_irq_data; /* our output to the world */
/* months start at 0 now */
static unsigned char days_in_mo[] =
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
static int irq_active;
#ifdef CONFIG_GEN_RTC_X
static struct work_struct genrtc_task;
static struct timer_list timer_task;
static unsigned int oldsecs;
static int lostint;
static unsigned long tt_exp;
static void gen_rtc_timer(unsigned long data);
static volatile int stask_active; /* schedule_work */
static volatile int ttask_active; /* timer_task */
static int stop_rtc_timers; /* don't requeue tasks */
static DEFINE_SPINLOCK(gen_rtc_lock);
static void gen_rtc_interrupt(unsigned long arg);
/*
* Routine to poll RTC seconds field for change as often as possible,
* after first RTC_UIE use timer to reduce polling
*/
static void genrtc_troutine(struct work_struct *work)
{
unsigned int tmp = get_rtc_ss();
if (stop_rtc_timers) {
stask_active = 0;
return;
}
if (oldsecs != tmp){
oldsecs = tmp;
timer_task.function = gen_rtc_timer;
timer_task.expires = jiffies + HZ - (HZ/10);
tt_exp=timer_task.expires;
ttask_active=1;
stask_active=0;
add_timer(&timer_task);
gen_rtc_interrupt(0);
} else if (schedule_work(&genrtc_task) == 0)
stask_active = 0;
}
static void gen_rtc_timer(unsigned long data)
{
lostint = get_rtc_ss() - oldsecs ;
if (lostint<0)
lostint = 60 - lostint;
if (time_after(jiffies, tt_exp))
printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
jiffies-tt_exp);
ttask_active=0;
stask_active=1;
if ((schedule_work(&genrtc_task) == 0))
stask_active = 0;
}
/*
* call gen_rtc_interrupt function to signal an RTC_UIE,
* arg is unused.
* Could be invoked either from a real interrupt handler or
* from some routine that periodically (eg 100HZ) monitors
* whether RTC_SECS changed
*/
static void gen_rtc_interrupt(unsigned long arg)
{
/* We store the status in the low byte and the number of
* interrupts received since the last read in the remainder
* of rtc_irq_data. */
gen_rtc_irq_data += 0x100;
gen_rtc_irq_data &= ~0xff;
gen_rtc_irq_data |= RTC_UIE;
if (lostint){
printk("genrtc: system delaying clock ticks?\n");
/* increment count so that userspace knows something is wrong */
gen_rtc_irq_data += ((lostint-1)<<8);
lostint = 0;
}
wake_up_interruptible(&gen_rtc_wait);
}
/*
* Now all the various file operations that we export.
*/
static ssize_t gen_rtc_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
unsigned long data;
ssize_t retval;
if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
return -EINVAL;
if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
return -EAGAIN;
retval = wait_event_interruptible(gen_rtc_wait,
(data = xchg(&gen_rtc_irq_data, 0)));
if (retval)
goto out;
/* first test allows optimizer to nuke this case for 32-bit machines */
if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
unsigned int uidata = data;
retval = put_user(uidata, (unsigned int __user *)buf) ?:
sizeof(unsigned int);
}
else {
retval = put_user(data, (unsigned long __user *)buf) ?:
sizeof(unsigned long);
}
out:
return retval;
}
static unsigned int gen_rtc_poll(struct file *file,
struct poll_table_struct *wait)
{
poll_wait(file, &gen_rtc_wait, wait);
if (gen_rtc_irq_data != 0)
return POLLIN | POLLRDNORM;
return 0;
}
#endif
/*
* Used to disable/enable interrupts, only RTC_UIE supported
* We also clear out any old irq data after an ioctl() that
* meddles with the interrupt enable/disable bits.
*/
static inline void gen_clear_rtc_irq_bit(unsigned char bit)
{
#ifdef CONFIG_GEN_RTC_X
stop_rtc_timers = 1;
if (ttask_active){
del_timer_sync(&timer_task);
ttask_active = 0;
}
while (stask_active)
schedule();
spin_lock(&gen_rtc_lock);
irq_active = 0;
spin_unlock(&gen_rtc_lock);
#endif
}
static inline int gen_set_rtc_irq_bit(unsigned char bit)
{
#ifdef CONFIG_GEN_RTC_X
spin_lock(&gen_rtc_lock);
if ( !irq_active ) {
irq_active = 1;
stop_rtc_timers = 0;
lostint = 0;
INIT_WORK(&genrtc_task, genrtc_troutine);
oldsecs = get_rtc_ss();
init_timer(&timer_task);
stask_active = 1;
if (schedule_work(&genrtc_task) == 0){
stask_active = 0;
}
}
spin_unlock(&gen_rtc_lock);
gen_rtc_irq_data = 0;
return 0;
#else
return -EINVAL;
#endif
}
static int gen_rtc_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct rtc_time wtime;
struct rtc_pll_info pll;
void __user *argp = (void __user *)arg;
switch (cmd) {
case RTC_PLL_GET:
if (get_rtc_pll(&pll))
return -EINVAL;
else
return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
case RTC_PLL_SET:
if (!capable(CAP_SYS_TIME))
return -EACCES;
if (copy_from_user(&pll, argp, sizeof(pll)))
return -EFAULT;
return set_rtc_pll(&pll);
case RTC_UIE_OFF: /* disable ints from RTC updates. */
gen_clear_rtc_irq_bit(RTC_UIE);
return 0;
case RTC_UIE_ON: /* enable ints for RTC updates. */
return gen_set_rtc_irq_bit(RTC_UIE);
case RTC_RD_TIME: /* Read the time/date from RTC */
/* this doesn't get week-day, who cares */
memset(&wtime, 0, sizeof(wtime));
get_rtc_time(&wtime);
return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
case RTC_SET_TIME: /* Set the RTC */
{
int year;
unsigned char leap_yr;
if (!capable(CAP_SYS_TIME))
return -EACCES;
if (copy_from_user(&wtime, argp, sizeof(wtime)))
return -EFAULT;
year = wtime.tm_year + 1900;
leap_yr = ((!(year % 4) && (year % 100)) ||
!(year % 400));
if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
return -EINVAL;
if (wtime.tm_mday < 0 || wtime.tm_mday >
(days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
return -EINVAL;
if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
wtime.tm_min < 0 || wtime.tm_min >= 60 ||
wtime.tm_sec < 0 || wtime.tm_sec >= 60)
return -EINVAL;
return set_rtc_time(&wtime);
}
}
return -EINVAL;
}
/*
* We enforce only one user at a time here with the open/close.
* Also clear the previous interrupt data on an open, and clean
* up things on a close.
*/
static int gen_rtc_open(struct inode *inode, struct file *file)
{
lock_kernel();
if (gen_rtc_status & RTC_IS_OPEN) {
unlock_kernel();
return -EBUSY;
}
gen_rtc_status |= RTC_IS_OPEN;
gen_rtc_irq_data = 0;
irq_active = 0;
unlock_kernel();
return 0;
}
static int gen_rtc_release(struct inode *inode, struct file *file)
{
/*
* Turn off all interrupts once the device is no longer
* in use and clear the data.
*/
gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
gen_rtc_status &= ~RTC_IS_OPEN;
return 0;
}
#ifdef CONFIG_PROC_FS
/*
* Info exported via "/proc/driver/rtc".
*/
static int gen_rtc_proc_output(char *buf)
{
char *p;
struct rtc_time tm;
unsigned int flags;
struct rtc_pll_info pll;
p = buf;
flags = get_rtc_time(&tm);
p += sprintf(p,
"rtc_time\t: %02d:%02d:%02d\n"
"rtc_date\t: %04d-%02d-%02d\n"
"rtc_epoch\t: %04u\n",
tm.tm_hour, tm.tm_min, tm.tm_sec,
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
p += sprintf(p, "alarm\t\t: ");
if (tm.tm_hour <= 24)
p += sprintf(p, "%02d:", tm.tm_hour);
else
p += sprintf(p, "**:");
if (tm.tm_min <= 59)
p += sprintf(p, "%02d:", tm.tm_min);
else
p += sprintf(p, "**:");
if (tm.tm_sec <= 59)
p += sprintf(p, "%02d\n", tm.tm_sec);
else
p += sprintf(p, "**\n");
p += sprintf(p,
"DST_enable\t: %s\n"
"BCD\t\t: %s\n"
"24hr\t\t: %s\n"
"square_wave\t: %s\n"
"alarm_IRQ\t: %s\n"
"update_IRQ\t: %s\n"
"periodic_IRQ\t: %s\n"
"periodic_freq\t: %ld\n"
"batt_status\t: %s\n",
(flags & RTC_DST_EN) ? "yes" : "no",
(flags & RTC_DM_BINARY) ? "no" : "yes",
(flags & RTC_24H) ? "yes" : "no",
(flags & RTC_SQWE) ? "yes" : "no",
(flags & RTC_AIE) ? "yes" : "no",
irq_active ? "yes" : "no",
(flags & RTC_PIE) ? "yes" : "no",
0L /* freq */,
(flags & RTC_BATT_BAD) ? "bad" : "okay");
if (!get_rtc_pll(&pll))
p += sprintf(p,
"PLL adjustment\t: %d\n"
"PLL max +ve adjustment\t: %d\n"
"PLL max -ve adjustment\t: %d\n"
"PLL +ve adjustment factor\t: %d\n"
"PLL -ve adjustment factor\t: %d\n"
"PLL frequency\t: %ld\n",
pll.pll_value,
pll.pll_max,
pll.pll_min,
pll.pll_posmult,
pll.pll_negmult,
pll.pll_clock);
return p - buf;
}
static int gen_rtc_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len = gen_rtc_proc_output (page);
if (len <= off+count) *eof = 1;
*start = page + off;
len -= off;
if (len>count) len = count;
if (len<0) len = 0;
return len;
}
static int __init gen_rtc_proc_init(void)
{
struct proc_dir_entry *r;
r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL);
if (!r)
return -ENOMEM;
return 0;
}
#else
static inline int gen_rtc_proc_init(void) { return 0; }
#endif /* CONFIG_PROC_FS */
/*
* The various file operations we support.
*/
static const struct file_operations gen_rtc_fops = {
.owner = THIS_MODULE,
#ifdef CONFIG_GEN_RTC_X
.read = gen_rtc_read,
.poll = gen_rtc_poll,
#endif
.ioctl = gen_rtc_ioctl,
.open = gen_rtc_open,
.release = gen_rtc_release,
};
static struct miscdevice rtc_gen_dev =
{
.minor = RTC_MINOR,
.name = "rtc",
.fops = &gen_rtc_fops,
};
static int __init rtc_generic_init(void)
{
int retval;
printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
retval = misc_register(&rtc_gen_dev);
if (retval < 0)
return retval;
retval = gen_rtc_proc_init();
if (retval) {
misc_deregister(&rtc_gen_dev);
return retval;
}
return 0;
}
static void __exit rtc_generic_exit(void)
{
remove_proc_entry ("driver/rtc", NULL);
misc_deregister(&rtc_gen_dev);
}
module_init(rtc_generic_init);
module_exit(rtc_generic_exit);
MODULE_AUTHOR("Richard Zidlicky");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(RTC_MINOR);
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