proc_misc.c

讲述linux的初始化过程

		"page %u %u\n"
                "swap %u %u\n"
		"intr %u",
			kstat.pgpgin,
			kstat.pgpgout,
			kstat.pswpin,
			kstat.pswpout,
			sum
	);
	for (i = 0 ; i < NR_IRQS ; i++)
		len += sprintf(page + len, " %u", kstat_irqs(i));

	len += sprintf(page + len, "\ndisk_io: ");

	for (major = 0; major < DK_MAX_MAJOR; major++) {
		for (disk = 0; disk < DK_MAX_DISK; disk++) {
			int active = kstat.dk_drive[major][disk] +
				kstat.dk_drive_rblk[major][disk] +
				kstat.dk_drive_wblk[major][disk];
			if (active)
				len += sprintf(page + len,
					"(%u,%u):(%u,%u,%u,%u,%u) ",
					major, disk,
					kstat.dk_drive[major][disk],
					kstat.dk_drive_rio[major][disk],
					kstat.dk_drive_rblk[major][disk],
					kstat.dk_drive_wio[major][disk],
					kstat.dk_drive_wblk[major][disk]
			);
		}
	}

	len += sprintf(page + len,
		"\nctxt %u\n"
		"btime %lu\n"
		"processes %lu\n",
		kstat.context_swtch,
		xtime.tv_sec - jif / HZ,
		total_forks);

	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int devices_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_device_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int partitions_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_partition_list(page, start, off, count);
	if (len < count) *eof = 1;
	return len;
}

#if !defined(CONFIG_ARCH_S390)
static int interrupts_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_irq_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}
#endif

static int filesystems_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_filesystem_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int dma_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_dma_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int ioports_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_ioport_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int cmdline_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	extern char saved_command_line[];
	int len;

	len = sprintf(page, "%s\n", saved_command_line);
	len = strlen(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

#ifdef CONFIG_SGI_DS1286
static int ds1286_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_ds1286_status(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}
#endif

static int locks_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len;
	lock_kernel();
	len = get_locks_status(page, start, off, count);
	unlock_kernel();
	if (len < count) *eof = 1;
	return len;
}

static int mounts_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_filesystem_info(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int execdomains_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_exec_domain_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int swaps_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_swaparea_info(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

static int memory_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = get_mem_list(page);
	return proc_calc_metrics(page, start, off, count, eof, len);
}

/*
 * This function accesses profiling information. The returned data is
 * binary: the sampling step and the actual contents of the profile
 * buffer. Use of the program readprofile is recommended in order to
 * get meaningful info out of these data.
 */
static ssize_t read_profile(struct file *file, char *buf,
			    size_t count, loff_t *ppos)
{
	unsigned long p = *ppos;
	ssize_t read;
	char * pnt;
	unsigned int sample_step = 1 << prof_shift;

	if (p >= (prof_len+1)*sizeof(unsigned int))
		return 0;
	if (count > (prof_len+1)*sizeof(unsigned int) - p)
		count = (prof_len+1)*sizeof(unsigned int) - p;
	read = 0;

	while (p < sizeof(unsigned int) && count > 0) {
		put_user(*((char *)(&sample_step)+p),buf);
		buf++; p++; count--; read++;
	}
	pnt = (char *)prof_buffer + p - sizeof(unsigned int);
	copy_to_user(buf,(void *)pnt,count);
	read += count;
	*ppos += read;
	return read;
}

/*
 * Writing to /proc/profile resets the counters
 *
 * Writing a 'profiling multiplier' value into it also re-sets the profiling
 * interrupt frequency, on architectures that support this.
 */
static ssize_t write_profile(struct file * file, const char * buf,
			     size_t count, loff_t *ppos)
{
#ifdef CONFIG_SMP
	extern int setup_profiling_timer (unsigned int multiplier);

	if (count==sizeof(int)) {
		unsigned int multiplier;

		if (copy_from_user(&multiplier, buf, sizeof(int)))
			return -EFAULT;

		if (setup_profiling_timer(multiplier))
			return -EINVAL;
	}
#endif

	memset(prof_buffer, 0, prof_len * sizeof(*prof_buffer));
	return count;
}

static struct file_operations proc_profile_operations = {
	read:		read_profile,
	write:		write_profile,
};

struct proc_dir_entry *proc_root_kcore;

void __init proc_misc_init(void)
{
	struct proc_dir_entry *entry;
	static struct {
		char *name;
		int (*read_proc)(char*,char**,off_t,int,int*,void*);
	} *p, simple_ones[] = {
		{"loadavg",     loadavg_read_proc},
		{"uptime",	uptime_read_proc},
		{"meminfo",	meminfo_read_proc},
		{"version",	version_read_proc},
		{"cpuinfo",	cpuinfo_read_proc},
#ifdef CONFIG_PROC_HARDWARE
		{"hardware",	hardware_read_proc},
#endif
#ifdef CONFIG_STRAM_PROC
		{"stram",	stram_read_proc},
#endif
#ifdef CONFIG_DEBUG_MALLOC
		{"malloc",	malloc_read_proc},
#endif
#ifdef CONFIG_MODULES
		{"modules",	modules_read_proc},
		{"ksyms",	ksyms_read_proc},
#endif
		{"stat",	kstat_read_proc},
		{"devices",	devices_read_proc},
		{"partitions",	partitions_read_proc},
#if !defined(CONFIG_ARCH_S390)
		{"interrupts",	interrupts_read_proc},
#endif
		{"filesystems",	filesystems_read_proc},
		{"dma",		dma_read_proc},
		{"ioports",	ioports_read_proc},
		{"cmdline",	cmdline_read_proc},
#ifdef CONFIG_SGI_DS1286
		{"rtc",		ds1286_read_proc},
#endif
		{"locks",	locks_read_proc},
		{"mounts",	mounts_read_proc},
		{"swaps",	swaps_read_proc},
		{"iomem",	memory_read_proc},
		{"execdomains",	execdomains_read_proc},
		{NULL,}
	};
	for (p = simple_ones; p->name; p++)
		create_proc_read_entry(p->name, 0, NULL, p->read_proc, NULL);

	/* And now for trickier ones */
	entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
	if (entry)
		entry->proc_fops = &proc_kmsg_operations;
	proc_root_kcore = create_proc_entry("kcore", S_IRUSR, NULL);
	if (proc_root_kcore) {
		proc_root_kcore->proc_fops = &proc_kcore_operations;
		proc_root_kcore->size =
				(size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
	}
	if (prof_shift) {
		entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL);
		if (entry) {
			entry->proc_fops = &proc_profile_operations;
			entry->size = (1+prof_len) * sizeof(unsigned int);
		}
	}
#ifdef __powerpc__
	{
		extern struct file_operations ppc_htab_operations;
		entry = create_proc_entry("ppc_htab", S_IRUGO|S_IWUSR, NULL);
		if (entry)
			entry->proc_fops = &ppc_htab_operations;
	}
#endif
	entry = create_proc_read_entry("slabinfo", S_IWUSR | S_IRUGO, NULL,
				       slabinfo_read_proc, NULL);
	if (entry)
		entry->write_proc = slabinfo_write_proc;
}