Console events and accessibility (b293d758) · Commits · 戴 / test

drivers/char/vt.c

+44 −1

Original line number	Diff line number	Diff line
		@@ -99,6 +99,7 @@
		#include <linux/pm.h>
		#include <linux/font.h>
		#include <linux/bitops.h>
		#include <linux/notifier.h>

		#include <asm/io.h>
		#include <asm/system.h>
		@@ -222,6 +223,35 @@ enum {
		blank_vesa_wait,
		};

		/*
		* Notifier list for console events.
		*/
		static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);

		int register_vt_notifier(struct notifier_block *nb)
		{
		return atomic_notifier_chain_register(&vt_notifier_list, nb);
		}
		EXPORT_SYMBOL_GPL(register_vt_notifier);

		int unregister_vt_notifier(struct notifier_block *nb)
		{
		return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
		}
		EXPORT_SYMBOL_GPL(unregister_vt_notifier);

		static void notify_write(struct vc_data *vc, unsigned int unicode)
		{
		struct vt_notifier_param param = { .vc = vc, unicode = unicode };
		atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
		}

		static void notify_update(struct vc_data *vc)
		{
		struct vt_notifier_param param = { .vc = vc };
		atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
		}

		/*
		* Low-Level Functions
		*/
		@@ -718,6 +748,7 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
		return -ENXIO;
		if (!vc_cons[currcons].d) {
		struct vc_data *vc;
		struct vt_notifier_param param;

		/* prevent users from taking too much memory */
		if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
		@@ -729,7 +760,7 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
		/* although the numbers above are not valid since long ago, the
		point is still up-to-date and the comment still has its value
		even if only as a historical artifact. --mj, July 1998 */
		vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
		param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
		if (!vc)
		return -ENOMEM;
		vc_cons[currcons].d = vc;
		@@ -746,6 +777,7 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
		}
		vc->vc_kmalloced = 1;
		vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
		atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
		}
		return 0;
		}
		@@ -907,6 +939,8 @@ void vc_deallocate(unsigned int currcons)

		if (vc_cons_allocated(currcons)) {
		struct vc_data *vc = vc_cons[currcons].d;
		struct vt_notifier_param param = { .vc = vc };
		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
		vc->vc_sw->con_deinit(vc);
		put_pid(vc->vt_pid);
		module_put(vc->vc_sw->owner);
		@@ -1019,6 +1053,7 @@ static void lf(struct vc_data *vc)
		vc->vc_pos += vc->vc_size_row;
		}
		vc->vc_need_wrap = 0;
		notify_write(vc, '\n');
		}

		static void ri(struct vc_data *vc)
		@@ -1039,6 +1074,7 @@ static inline void cr(struct vc_data *vc)
		{
		vc->vc_pos -= vc->vc_x << 1;
		vc->vc_need_wrap = vc->vc_x = 0;
		notify_write(vc, '\r');
		}

		static inline void bs(struct vc_data *vc)
		@@ -1047,6 +1083,7 @@ static inline void bs(struct vc_data *vc)
		vc->vc_pos -= 2;
		vc->vc_x--;
		vc->vc_need_wrap = 0;
		notify_write(vc, '\b');
		}
		}

		@@ -1593,6 +1630,7 @@ static void do_con_trol(struct tty_struct tty, struct vc_data vc, int c)
		break;
		}
		vc->vc_pos += (vc->vc_x << 1);
		notify_write(vc, '\t');
		return;
		case 10: case 11: case 12:
		lf(vc);
		@@ -2252,6 +2290,7 @@ rescan_last_byte:
		tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
		if (tc < 0) tc = ' ';
		}
		notify_write(vc, c);

		if (inverse) {
		FLUSH
		@@ -2274,6 +2313,7 @@ rescan_last_byte:
		release_console_sem();

		out:
		notify_update(vc);
		return n;
		#undef FLUSH
		}
		@@ -2317,6 +2357,7 @@ static void console_callback(struct work_struct *ignored)
		do_blank_screen(0);
		blank_timer_expired = 0;
		}
		notify_update(vc_cons[fg_console].d);

		release_console_sem();
		}
		@@ -2418,6 +2459,7 @@ static void vt_console_print(struct console co, const char b, unsigned count)
		continue;
		}
		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
		notify_write(vc, c);
		cnt++;
		if (myx == vc->vc_cols - 1) {
		vc->vc_need_wrap = 1;
		@@ -2436,6 +2478,7 @@ static void vt_console_print(struct console co, const char b, unsigned count)
		}
		}
		set_cursor(vc);
		notify_update(vc);

		quit:
		clear_bit(0, &printing);

include/linux/notifier.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -242,5 +242,11 @@ static inline int notifier_to_errno(int ret)

		extern struct blocking_notifier_head reboot_notifier_list;

		/* Virtual Terminal events. */
		#define VT_ALLOCATE 0x0001 /* Console got allocated */
		#define VT_DEALLOCATE 0x0002 /* Console will be deallocated */
		#define VT_WRITE 0x0003 /* A char got output */
		#define VT_UPDATE 0x0004 /* A bigger update occurred */

		#endif /* __KERNEL__ */
		#endif /* _LINUX_NOTIFIER_H */

include/linux/vt.h

+12 −0

Original line number	Diff line number	Diff line
		#ifndef _LINUX_VT_H
		#define _LINUX_VT_H

		#ifdef __KERNEL__
		struct notifier_block;

		struct vt_notifier_param {
		struct vc_data vc; / VC on which the update happened */
		unsigned int c; /* Printed char */
		};

		extern int register_vt_notifier(struct notifier_block *nb);
		extern int unregister_vt_notifier(struct notifier_block *nb);
		#endif

		/*
		* These constants are also useful for user-level apps (e.g., VC
		* resizing).

Admin message