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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs...
[net-next-2.6.git] / drivers / s390 / char / ctrlchar.c
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1/*
2 * drivers/s390/char/ctrlchar.c
3 * Unified handling of special chars.
4 *
5 * Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
7 *
8 */
9
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10#include <linux/stddef.h>
11#include <asm/errno.h>
12#include <linux/sysrq.h>
13#include <linux/ctype.h>
14
15#include "ctrlchar.h"
16
17#ifdef CONFIG_MAGIC_SYSRQ
18static int ctrlchar_sysrq_key;
19
20static void
e45ccc05 21ctrlchar_handle_sysrq(struct work_struct *work)
1da177e4 22{
f335397d 23 handle_sysrq(ctrlchar_sysrq_key);
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24}
25
e45ccc05 26static DECLARE_WORK(ctrlchar_work, ctrlchar_handle_sysrq);
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27#endif
28
29
30/**
31 * Check for special chars at start of input.
32 *
33 * @param buf Console input buffer.
34 * @param len Length of valid data in buffer.
35 * @param tty The tty struct for this console.
36 * @return CTRLCHAR_NONE, if nothing matched,
37 * CTRLCHAR_SYSRQ, if sysrq was encountered
38 * otherwise char to be inserted logically or'ed
39 * with CTRLCHAR_CTRL
40 */
41unsigned int
42ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
43{
44 if ((len < 2) || (len > 3))
45 return CTRLCHAR_NONE;
46
47 /* hat is 0xb1 in codepage 037 (US etc.) and thus */
48 /* converted to 0x5e in ascii ('^') */
49 if ((buf[0] != '^') && (buf[0] != '\252'))
50 return CTRLCHAR_NONE;
51
52#ifdef CONFIG_MAGIC_SYSRQ
53 /* racy */
54 if (len == 3 && buf[1] == '-') {
55 ctrlchar_sysrq_key = buf[2];
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56 schedule_work(&ctrlchar_work);
57 return CTRLCHAR_SYSRQ;
58 }
59#endif
60
61 if (len != 2)
62 return CTRLCHAR_NONE;
63
64 switch (tolower(buf[1])) {
65 case 'c':
66 return INTR_CHAR(tty) | CTRLCHAR_CTRL;
67 case 'd':
68 return EOF_CHAR(tty) | CTRLCHAR_CTRL;
69 case 'z':
70 return SUSP_CHAR(tty) | CTRLCHAR_CTRL;
71 }
72 return CTRLCHAR_NONE;
73}