proc: move sysrq-trigger out of fs/proc/

Move it into sysrq.c, along with the rest of the sysrq implementation.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 2aa79ab..dce4cc0 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -23,6 +23,7 @@
 #include <linux/reboot.h>
 #include <linux/sysrq.h>
 #include <linux/kbd_kern.h>
+#include <linux/proc_fs.h>
 #include <linux/quotaops.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -534,3 +535,32 @@ int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
 	return __sysrq_swap_key_ops(key, NULL, op_p);
 }
 EXPORT_SYMBOL(unregister_sysrq_key);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ */
+static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	if (count) {
+		char c;
+
+		if (get_user(c, buf))
+			return -EFAULT;
+		__handle_sysrq(c, NULL, 0);
+	}
+	return count;
+}
+
+static const struct file_operations proc_sysrq_trigger_operations = {
+	.write		= write_sysrq_trigger,
+};
+
+static int __init sysrq_init(void)
+{
+	proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations);
+	return 0;
+}
+module_init(sysrq_init);
+#endif