Commit 6c87df37 authored by Alexey Dobriyan's avatar Alexey Dobriyan

proc: revert /proc/uptime to ->read_proc hook

Turned out some VMware userspace does pread(2) on /proc/uptime, but
seqfiles currently don't allow pread() resulting in -ESPIPE.

Seqfiles in theory can do pread(), but this can be a long story,
so revert to ->read_proc until then. default avatarAlexey Dobriyan <>
parent e013e13b
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/time.h>
#include <asm/cputime.h>
static int uptime_proc_show(struct seq_file *m, void *v)
static int proc_calc_metrics(char *page, char **start, off_t off,
int count, int *eof, int len)
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 uptime_read_proc(char *page, char **start, off_t off, int count,
int *eof, void *data)
struct timespec uptime;
struct timespec idle;
int len;
cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
cputime_to_timespec(idletime, &idle);
seq_printf(m, "%lu.%02lu %lu.%02lu\n",
len = sprintf(page, "%lu.%02lu %lu.%02lu\n",
(unsigned long) uptime.tv_sec,
(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
(unsigned long) idle.tv_sec,
(idle.tv_nsec / (NSEC_PER_SEC / 100)));
return 0;
return proc_calc_metrics(page, start, off, count, eof, len);
static int uptime_proc_open(struct inode *inode, struct file *file)
return single_open(file, uptime_proc_show, NULL);
static const struct file_operations uptime_proc_fops = {
.open = uptime_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
static int __init proc_uptime_init(void)
proc_create("uptime", 0, NULL, &uptime_proc_fops);
create_proc_read_entry("uptime", 0, NULL, uptime_read_proc, NULL);
return 0;
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