Commit 730760e9 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

[PATCH] uml: locking documentation

Some locking documentation and a cleanup.  uml_exitcode is copied into a local
before sprintf sees it, in case sprintf does anything non-atomic with it.

The rest are comments about why certain globals don't need any kind of
locking.
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b10aeeef
......@@ -8,6 +8,7 @@
#include "chan_user.h"
#include "os.h"
/* This address is used only as a unique identifer */
static int null_chan;
static void *null_init(char *str, int device, const struct chan_opts *opts)
......
......@@ -20,6 +20,10 @@
#define RNG_MISCDEV_MINOR 183 /* official */
/* Changed at init time, in the non-modular case, and at module load
* time, in the module case. Presumably, the module subsystem
* protects against a module being loaded twice at the same time.
*/
static int random_fd = -1;
static int rng_dev_open (struct inode *inode, struct file *filp)
......
......@@ -9,6 +9,8 @@
/*
* Don't register by default -- as this registeres very early in the
* boot process it becomes the default console.
*
* Initialized at init time.
*/
static int use_stderr_console = 0;
......
......@@ -108,6 +108,7 @@ static int con_open(struct tty_struct *tty, struct file *filp)
return line_open(vts, tty);
}
/* Set in an initcall, checked in an exitcall */
static int con_init_done = 0;
static const struct tty_operations console_ops = {
......
......@@ -16,9 +16,13 @@ int uml_exitcode = 0;
static int read_proc_exitcode(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len;
int len, val;
len = sprintf(page, "%d\n", uml_exitcode);
/* 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;
......
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