[PATCH] reduce pty.c ifdef clutter

From: Christoph Hellwig
Date: Sat Aug 14 2004 - 09:36:27 EST


- build only if either CONFIG_LEGACY_PTYS or CONFIG_UNIX98_PTYS are set
instead of testing in the file
- try to keep big CONFIG_LEGACY_PTYS and CONFIG_UNIX98_PTYS ifdef
blocks at the end of the file instead of cluttering all over


--- 1.75/drivers/char/Makefile 2004-07-29 06:58:35 +02:00
+++ edited/drivers/char/Makefile 2004-08-13 16:31:11 +02:00
@@ -7,8 +7,11 @@
#
FONTMAPFILE = cp437.uni

-obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o pty.o misc.o
+obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o

+obj-$(CONFIG_LEGACY_PTYS) += pty.o
+obj-$(CONFIG_UNIX98_PTYS) += pty.o
+obj-y += misc.o
obj-$(CONFIG_VT) += vt_ioctl.o vc_screen.o consolemap.o \
consolemap_deftbl.o selection.o keyboard.o
obj-$(CONFIG_HW_CONSOLE) += vt.o defkeymap.o
===== drivers/char/pty.c 1.26 vs edited =====
--- 1.26/drivers/char/pty.c 2004-06-30 08:02:10 +02:00
+++ edited/drivers/char/pty.c 2004-08-13 16:50:22 +02:00
@@ -32,12 +32,6 @@
#include <asm/bitops.h>
#include <linux/devpts_fs.h>

-#if defined(CONFIG_LEGACY_PTYS) || defined(CONFIG_UNIX98_PTYS)
-
-#ifdef CONFIG_LEGACY_PTYS
-static struct tty_driver *pty_driver, *pty_slave_driver;
-#endif
-
/* These are global because they are accessed in tty_io.c */
#ifdef CONFIG_UNIX98_PTYS
struct tty_driver *ptm_driver;
@@ -205,19 +199,6 @@
return ((count < N_TTY_BUF_SIZE/2) ? 0 : count);
}

-/*
- * Return the device number of a Unix98 PTY (only!). This lets us open a
- * master pty with the multi-headed ptmx device, then find out which
- * one we got after it is open, with an ioctl.
- */
-#ifdef CONFIG_UNIX98_PTYS
-static int pty_get_device_number(struct tty_struct *tty, unsigned __user *value)
-{
- unsigned int result = tty->index;
- return put_user(result, value);
-}
-#endif
-
/* Set the lock flag on a pty */
static int pty_set_lock(struct tty_struct *tty, int __user * arg)
{
@@ -231,41 +212,6 @@
return 0;
}

-#ifdef CONFIG_LEGACY_PTYS
-static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- if (!tty) {
- printk("pty_ioctl called with NULL tty!\n");
- return -EIO;
- }
- switch(cmd) {
- case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
- return pty_set_lock(tty, (int __user *) arg);
- }
- return -ENOIOCTLCMD;
-}
-#endif
-
-#ifdef CONFIG_UNIX98_PTYS
-static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- if (!tty) {
- printk("pty_unix98_ioctl called with NULL tty!\n");
- return -EIO;
- }
- switch(cmd) {
- case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
- return pty_set_lock(tty, (int __user *)arg);
- case TIOCGPTN: /* Get PT Number */
- return pty_get_device_number(tty, (unsigned int __user *)arg);
- }
-
- return -ENOIOCTLCMD;
-}
-#endif
-
static void pty_flush_buffer(struct tty_struct *tty)
{
struct tty_struct *to = tty->link;
@@ -322,42 +268,22 @@
.set_termios = pty_set_termios,
};

-/* sysctl support for setting limits on the number of Unix98 ptys allocated.
- Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. */
-#ifdef CONFIG_UNIX98_PTYS
-int pty_limit = NR_UNIX98_PTY_DEFAULT;
-static int pty_limit_min = 0;
-static int pty_limit_max = NR_UNIX98_PTY_MAX;
+/* Traditional BSD devices */
+#ifdef CONFIG_LEGACY_PTYS
+static struct tty_driver *pty_driver, *pty_slave_driver;

-ctl_table pty_table[] = {
- {
- .ctl_name = PTY_MAX,
- .procname = "max",
- .maxlen = sizeof(int),
- .mode = 0644,
- .data = &pty_limit,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &pty_limit_min,
- .extra2 = &pty_limit_max,
- }, {
- .ctl_name = PTY_NR,
- .procname = "nr",
- .maxlen = sizeof(int),
- .mode = 0444,
- .proc_handler = &proc_dointvec,
- }, {
- .ctl_name = 0
+static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+ return pty_set_lock(tty, (int __user *) arg);
}
-};
-#endif
-
-/* Initialization */
+ return -ENOIOCTLCMD;
+}

-static int __init pty_init(void)
+static void __init legacy_pty_init(void)
{
-#ifdef CONFIG_LEGACY_PTYS
- /* Traditional BSD devices */

pty_driver = alloc_tty_driver(NR_PTYS);
if (!pty_driver)
@@ -404,11 +330,58 @@
panic("Couldn't register pty driver");
if (tty_register_driver(pty_slave_driver))
panic("Couldn't register pty slave driver");
+}
+#else
+static inline void legacy_pty_init(void) { }
+#endif

-#endif /* CONFIG_LEGACY_PTYS */
-
+/* Unix98 devices */
#ifdef CONFIG_UNIX98_PTYS
- /* Unix98 devices */
+/*
+ * sysctl support for setting limits on the number of Unix98 ptys allocated.
+ * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
+ */
+int pty_limit = NR_UNIX98_PTY_DEFAULT;
+static int pty_limit_min = 0;
+static int pty_limit_max = NR_UNIX98_PTY_MAX;
+
+ctl_table pty_table[] = {
+ {
+ .ctl_name = PTY_MAX,
+ .procname = "max",
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .data = &pty_limit,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &pty_limit_min,
+ .extra2 = &pty_limit_max,
+ }, {
+ .ctl_name = PTY_NR,
+ .procname = "nr",
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ }, {
+ .ctl_name = 0
+ }
+};
+
+static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+ return pty_set_lock(tty, (int __user *)arg);
+ case TIOCGPTN: /* Get PT Number */
+ return put_user(tty->index, (unsigned int __user *)arg);
+ }
+
+ return -ENOIOCTLCMD;
+}
+
+static void __init unix98_pty_init(void)
+{
devfs_mk_dir("pts");
ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
if (!ptm_driver)
@@ -455,10 +428,15 @@
panic("Couldn't register Unix98 pts driver");

pty_table[1].data = &ptm_driver->refcount;
-#endif /* CONFIG_UNIX98_PTYS */
+}
+#else
+static inline void unix98_pty_init(void) { }
+#endif

+static int __init pty_init(void)
+{
+ legacy_pty_init();
+ unix98_pty_init();
return 0;
}
module_init(pty_init);
-
-#endif /* CONFIG_LEGACY_PTYS || CONFIG_UNIX98_PTYS */
-
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