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| 2 | |
| 3 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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| 4 |
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| 5 |
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| 6 | #include <linux/ctype.h>
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| 7 | #include <linux/init.h>
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| 8 | #include <linux/kernel.h>
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| 9 | #include <linux/module.h>
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| 10 | #include <linux/proc_fs.h>
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| 11 | #include <linux/seq_file.h>
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| 12 | #include <linux/types.h>
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| 13 | #include <linux/uaccess.h>
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| 14 |
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| 15 | |
| 16 | * If read and write race, the read will still atomically read a valid
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| 17 | * value.
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| 18 |
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| 19 | int uml_exitcode = 0;
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| 20 |
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| 21 | static int exitcode_proc_show(struct seq_file *m, void *v)
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| 22 | {
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| 23 | int val;
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| 24 |
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| 25 | |
| 26 | * Save uml_exitcode in a local so that we don't need to guarantee
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| 27 | * that sprintf accesses it atomically.
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| 28 |
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| 29 | val = uml_exitcode;
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| 30 | seq_printf(m, "%d\n", val);
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| 31 | return 0;
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| 32 | }
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| 33 |
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| 34 | static int exitcode_proc_open(struct inode *inode, struct file *file)
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| 35 | {
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| 36 | return single_open(file, exitcode_proc_show, NULL);
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| 37 | }
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| 38 |
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| 39 | static ssize_t exitcode_proc_write(struct file *file,
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| 40 | const char __user *buffer, size_t count, loff_t *pos)
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| 41 | {
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| 42 | char *end, buf[sizeof("nnnnn\0")];
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| 43 | size_t size;
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| 44 | int tmp;
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| 45 |
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| 46 | size = min(count, sizeof(buf));
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| 47 | if (copy_from_user(buf, buffer, size))
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| 48 | return -EFAULT;
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| 49 |
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| 50 | tmp = simple_strtol(buf, &end, 0);
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| 51 | if ((*end != '\0') && !isspace(*end))
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| 52 | return -EINVAL;
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| 53 |
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| 54 | uml_exitcode = tmp;
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| 55 | return count;
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| 56 | }
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| 57 |
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| 58 | static const struct proc_ops exitcode_proc_ops = {
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| 59 | .proc_open = exitcode_proc_open,
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| 60 | .proc_read = seq_read,
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| 61 | .proc_lseek = seq_lseek,
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| 62 | .proc_release = single_release,
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| 63 | .proc_write = exitcode_proc_write,
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| 64 | };
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| 65 |
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| 66 | static int make_proc_exitcode(void)
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| 67 | {
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| 68 | struct proc_dir_entry *ent;
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| 69 |
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| 70 | ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_ops);
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| 71 | if (ent == NULL) {
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| 72 | printk(KERN_WARNING "make_proc_exitcode : Failed to register "
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| 73 | "/proc/exitcode\n");
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| 74 | return 0;
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| 75 | }
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| 76 | return 0;
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| 77 | }
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| 78 |
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| 79 | __initcall(make_proc_exitcode);
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