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authorKarl Dahlke <eklhad@comcast.net>2008-04-28 02:14:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:32 -0700
commit0341a4d0fdd2a0a3d9e2bb3a9afef9f8292c8502 (patch)
treee073b06ad0d0e4a7d3aaed487db0655feadb31bb
parentf7440b0ecdeb3a04d07c546d02d29700d2a574b7 (diff)
VT notifier extension for accessibility
Some accessibility modules need to be able to catch the output on the console before the VT interpretation, and possibly swallow it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/char/vt.c8
-rw-r--r--include/linux/notifier.h1
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 9b58b894f82..df4c3ead9e2 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2054,6 +2054,7 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
unsigned long draw_from = 0, draw_to = 0;
struct vc_data *vc;
unsigned char vc_attr;
+ struct vt_notifier_param param;
uint8_t rescan;
uint8_t inverse;
uint8_t width;
@@ -2113,6 +2114,8 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
if (IS_FG(vc))
hide_cursor(vc);
+ param.vc = vc;
+
while (!tty->stopped && count) {
int orig = *buf;
c = orig;
@@ -2201,6 +2204,11 @@ rescan_last_byte:
tc = vc->vc_translate[vc->vc_toggle_meta ? (c | 0x80) : c];
}
+ param.c = tc;
+ if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
+ &param) == NOTIFY_STOP)
+ continue;
+
/* If the original code was a control character we
* only allow a glyph to be displayed if the code is
* not normally used (such as for cursor movement) or
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index f4df40038f0..20dfed59018 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -247,6 +247,7 @@ extern struct blocking_notifier_head reboot_notifier_list;
#define VT_DEALLOCATE 0x0002 /* Console will be deallocated */
#define VT_WRITE 0x0003 /* A char got output */
#define VT_UPDATE 0x0004 /* A bigger update occurred */
+#define VT_PREWRITE 0x0005 /* A char is about to be written to the console */
#endif /* __KERNEL__ */
#endif /* _LINUX_NOTIFIER_H */