mirror of
https://github.com/torvalds/linux.git
synced 2024-11-12 07:01:57 +00:00
730760e90a
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: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
/*
|
|
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#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)
|
|
{
|
|
return(&null_chan);
|
|
}
|
|
|
|
static int null_open(int input, int output, int primary, void *d,
|
|
char **dev_out)
|
|
{
|
|
*dev_out = NULL;
|
|
return(os_open_file(DEV_NULL, of_rdwr(OPENFLAGS()), 0));
|
|
}
|
|
|
|
static int null_read(int fd, char *c_out, void *unused)
|
|
{
|
|
return(-ENODEV);
|
|
}
|
|
|
|
static void null_free(void *data)
|
|
{
|
|
}
|
|
|
|
const struct chan_ops null_ops = {
|
|
.type = "null",
|
|
.init = null_init,
|
|
.open = null_open,
|
|
.close = generic_close,
|
|
.read = null_read,
|
|
.write = generic_write,
|
|
.console_write = generic_console_write,
|
|
.window_size = generic_window_size,
|
|
.free = null_free,
|
|
.winch = 0,
|
|
};
|
|
|
|
/*
|
|
* Overrides for Emacs so that we follow Linus's tabbing style.
|
|
* Emacs will notice this stuff at the end of the file and automatically
|
|
* adjust the settings for this buffer only. This must remain at the end
|
|
* of the file.
|
|
* ---------------------------------------------------------------------------
|
|
* Local variables:
|
|
* c-file-style: "linux"
|
|
* End:
|
|
*/
|