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
786d7e1612f0b0adb6046f19b906609e4fe8b1ba "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>
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 4a28a15..2f910a1 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -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 @@
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 @@
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 @@
return 0;
}
- ent->read_proc = proc_read_sysemu;
- ent->write_proc = proc_write_sysemu;
-
return 0;
}