uml: convert to seq_file/proc_fops

Convert code away from ->read_proc/->write_proc interfaces.  Switch to
proc_create()/proc_create_data() which make addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.

Problem with ->read_proc et al is described here commit
786d7e1612 "Fix rmmod/read/write races in
/proc entries"

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2009-12-14 18:00:11 -08:00 committed by Linus Torvalds
parent 2886a8bdfa
commit 6613c5e860
4 changed files with 71 additions and 55 deletions

View file

@ -833,8 +833,8 @@ static int __init mconsole_init(void)
__initcall(mconsole_init);
static int write_proc_mconsole(struct file *file, const char __user *buffer,
unsigned long count, void *data)
static ssize_t mconsole_proc_write(struct file *file,
const char __user *buffer, size_t count, loff_t *pos)
{
char *buf;
@ -855,6 +855,11 @@ static int write_proc_mconsole(struct file *file, const char __user *buffer,
return count;
}
static const struct file_operations mconsole_proc_fops = {
.owner = THIS_MODULE,
.write = mconsole_proc_write,
};
static int create_proc_mconsole(void)
{
struct proc_dir_entry *ent;
@ -862,15 +867,12 @@ static int create_proc_mconsole(void)
if (notify_socket == NULL)
return 0;
ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops);
if (ent == NULL) {
printk(KERN_INFO "create_proc_mconsole : create_proc_entry "
"failed\n");
return 0;
}
ent->read_proc = NULL;
ent->write_proc = write_proc_mconsole;
return 0;
}

View file

@ -27,6 +27,7 @@
#include "linux/init.h"
#include "linux/cdrom.h"
#include "linux/proc_fs.h"
#include "linux/seq_file.h"
#include "linux/ctype.h"
#include "linux/capability.h"
#include "linux/mm.h"
@ -200,23 +201,25 @@ static void make_proc_ide(void)
proc_ide = proc_mkdir("ide0", proc_ide_root);
}
static int proc_ide_read_media(char *page, char **start, off_t off, int count,
int *eof, void *data)
static int fake_ide_media_proc_show(struct seq_file *m, void *v)
{
int len;
strcpy(page, "disk\n");
len = strlen("disk\n");
len -= off;
if (len < count){
*eof = 1;
if (len <= 0) return 0;
}
else len = count;
*start = page + off;
return len;
seq_puts(m, "disk\n");
return 0;
}
static int fake_ide_media_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, fake_ide_media_proc_show, NULL);
}
static const struct file_operations fake_ide_media_proc_fops = {
.owner = THIS_MODULE,
.open = fake_ide_media_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void make_ide_entries(const char *dev_name)
{
struct proc_dir_entry *dir, *ent;
@ -227,11 +230,8 @@ static void make_ide_entries(const char *dev_name)
dir = proc_mkdir(dev_name, proc_ide);
if(!dir) return;
ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir);
ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops);
if(!ent) return;
ent->data = NULL;
ent->read_proc = proc_ide_read_media;
ent->write_proc = NULL;
snprintf(name, sizeof(name), "ide0/%s", dev_name);
proc_symlink(dev_name, proc_ide_root, name);
}

View file

@ -6,7 +6,9 @@
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/types.h>
#include <asm/uaccess.h>
@ -16,30 +18,26 @@
*/
int uml_exitcode = 0;
static int read_proc_exitcode(char *page, char **start, off_t off,
int count, int *eof, void *data)
static int exitcode_proc_show(struct seq_file *m, void *v)
{
int len, val;
int val;
/*
* Save uml_exitcode in a local so that we don't need to guarantee
* that sprintf accesses it atomically.
*/
val = uml_exitcode;
len = sprintf(page, "%d\n", val);
len -= off;
if (len <= off+count)
*eof = 1;
*start = page + off;
if (len > count)
len = count;
if (len < 0)
len = 0;
return len;
seq_printf(m, "%d\n", val);
return 0;
}
static int write_proc_exitcode(struct file *file, const char __user *buffer,
unsigned long count, void *data)
static int exitcode_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, exitcode_proc_show, NULL);
}
static ssize_t exitcode_proc_write(struct file *file,
const char __user *buffer, size_t count, loff_t *pos)
{
char *end, buf[sizeof("nnnnn\0")];
int tmp;
@ -55,20 +53,25 @@ static int write_proc_exitcode(struct file *file, const char __user *buffer,
return count;
}
static const struct file_operations exitcode_proc_fops = {
.owner = THIS_MODULE,
.open = exitcode_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = exitcode_proc_write,
};
static int make_proc_exitcode(void)
{
struct proc_dir_entry *ent;
ent = create_proc_entry("exitcode", 0600, NULL);
ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_fops);
if (ent == NULL) {
printk(KERN_WARNING "make_proc_exitcode : Failed to register "
"/proc/exitcode\n");
return 0;
}
ent->read_proc = read_proc_exitcode;
ent->write_proc = write_proc_exitcode;
return 0;
}

View file

@ -9,11 +9,13 @@
#include <linux/hardirq.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/proc_fs.h>
#include <linux/ptrace.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/tick.h>
#include <linux/threads.h>
#include <asm/current.h>
@ -336,16 +338,19 @@ int get_using_sysemu(void)
return atomic_read(&using_sysemu);
}
static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
static int sysemu_proc_show(struct seq_file *m, void *v)
{
if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size)
/* No overflow */
*eof = 1;
return strlen(buf);
seq_printf(m, "%d\n", get_using_sysemu());
return 0;
}
static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
static int sysemu_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, sysemu_proc_show, NULL);
}
static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
size_t count, loff_t *pos)
{
char tmp[2];
@ -358,13 +363,22 @@ static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned
return count;
}
static const struct file_operations sysemu_proc_fops = {
.owner = THIS_MODULE,
.open = sysemu_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = sysemu_proc_write,
};
int __init make_proc_sysemu(void)
{
struct proc_dir_entry *ent;
if (!sysemu_supported)
return 0;
ent = create_proc_entry("sysemu", 0600, NULL);
ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
if (ent == NULL)
{
@ -372,9 +386,6 @@ int __init make_proc_sysemu(void)
return 0;
}
ent->read_proc = proc_read_sysemu;
ent->write_proc = proc_write_sysemu;
return 0;
}