patch-2.4.19 linux-2.4.19/drivers/char/rtc.c

• Lines: 122
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/drivers/char/rtc.c
• Orig date: Fri Dec 21 09:41:54 2001

diff -urN linux-2.4.18/drivers/char/rtc.c linux-2.4.19/drivers/char/rtc.c
@@ -67,6 +67,7 @@
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
+#include <linux/sysctl.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
@@ -138,6 +139,7 @@
 static unsigned long rtc_status = 0;	/* bitmapped status byte.	*/
 static unsigned long rtc_freq = 0;	/* Current periodic IRQ rate	*/
 static unsigned long rtc_irq_data = 0;	/* our output to the world	*/
+static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
 
 /*
  *	If this driver ever becomes modularised, it will be really nice
@@ -187,6 +189,38 @@
 #endif
 
 /*
+ * sysctl-tuning infrastructure.
+ */
+static ctl_table rtc_table[] = {
+    { 1, "max-user-freq", &rtc_max_user_freq, sizeof(int), 0644, NULL,
+      &proc_dointvec, NULL, },
+    { 0, }
+};
+
+static ctl_table rtc_root[] = {
+    { 1, "rtc", NULL, 0, 0555, rtc_table, },
+    { 0, }
+};
+
+static ctl_table dev_root[] = {
+    { CTL_DEV, "dev", NULL, 0, 0555, rtc_root, },
+    { 0, }
+};
+
+static struct ctl_table_header *sysctl_header;
+
+static int __init init_sysctl(void)
+{
+    sysctl_header = register_sysctl_table(dev_root, 0);
+    return 0;
+}
+
+static void __exit cleanup_sysctl(void)
+{
+    unregister_sysctl_table(sysctl_header);
+}
+
+/*
  *	Now all the various file operations that we export.
  */
 
@@ -295,7 +329,8 @@
 		 * We don't really want Joe User enabling more
 		 * than 64Hz of interrupts on a multi-user machine.
 		 */
-		if ((rtc_freq > 64) && (!capable(CAP_SYS_RESOURCE)))
+		if ((rtc_freq > rtc_max_user_freq) && 
+		    (!capable(CAP_SYS_RESOURCE)))
 			return -EACCES;
 
 		if (!(rtc_status & RTC_TIMER_ON)) {
@@ -493,7 +528,7 @@
 		 * We don't really want Joe User generating more
 		 * than 64Hz of interrupts on a multi-user machine.
 		 */
-		if ((arg > 64) && (!capable(CAP_SYS_RESOURCE)))
+		if ((arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
 			return -EACCES;
 
 		while (arg > (1<<tmp))
@@ -534,7 +569,7 @@
 		return 0;
 	}
 	default:
-		return -EINVAL;
+		return -ENOTTY;
 	}
 	return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
 }
@@ -720,7 +755,7 @@
 	}
 no_irq:
 #else
-	if (check_region (RTC_PORT (0), RTC_IO_EXTENT))
+	if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"))
 	{
 		printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0));
 		return -EIO;
@@ -731,11 +766,11 @@
 	{
 		/* Yeah right, seeing as irq 8 doesn't even hit the bus. */
 		printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
+		release_region(RTC_PORT(0), RTC_IO_EXTENT);
 		return -EIO;
 	}
 #endif
 
-	request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc");
 #endif /* __sparc__ vs. others */
 
 	misc_register(&rtc_dev);
@@ -798,6 +833,8 @@
 no_irq2:
 #endif
 
+	(void) init_sysctl();
+
 	printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
 
 	return 0;
@@ -805,6 +842,7 @@
 
 static void __exit rtc_exit (void)
 {
+	cleanup_sysctl();
 	remove_proc_entry ("driver/rtc", NULL);
 	misc_deregister(&rtc_dev);