From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: [PATCH 3/6] vt: push down tioclinux cases
Date: Fri, 02 Mar 2012 14:59:37 +0000 [thread overview]
Message-ID: <20120302145931.32320.8135.stgit@bob.linux.org.uk> (raw)
In-Reply-To: <20120302145628.32320.53944.stgit@bob.linux.org.uk>
From: Alan Cox <alan@linux.intel.com>
Some of this ventures into selection which is still a complete lost cause. We
are not making it any worse. It's completely busted anyway.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/tty/vt/selection.c | 12 ++++++------
drivers/tty/vt/vt.c | 12 ++++++++++++
drivers/tty/vt/vt_ioctl.c | 2 --
3 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 738e45a..2a50916 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -75,7 +75,7 @@ clear_selection(void) {
/*
* User settable table: what characters are to be considered alphabetic?
- * 256 bits
+ * 256 bits. FIXME: Needs a locking model.
*/
static u32 inwordLut[8]={
0x00000000, /* control chars */
@@ -307,7 +307,8 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
* queue of the tty associated with the current console.
* Invoked by ioctl().
*
- * Locking: always called with BTM from vt_ioctl
+ * Locking: called without locks. Calls the ldisc wrongly with
+ * unsafe methods,
*/
int paste_selection(struct tty_struct *tty)
{
@@ -322,13 +323,12 @@ int paste_selection(struct tty_struct *tty)
poke_blanked_console();
console_unlock();
+ /* FIXME: wtf is this supposed to achieve ? */
ld = tty_ldisc_ref(tty);
- if (!ld) {
- tty_unlock();
+ if (!ld)
ld = tty_ldisc_ref_wait(tty);
- tty_lock();
- }
+ /* FIXME: this is completely unsafe */
add_wait_queue(&vc->paste_wait, &wait);
while (sel_buffer && sel_buffer_lth > pasted) {
set_current_state(TASK_INTERRUPTIBLE);
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 8439303..280a4c4 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2637,11 +2637,15 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
ret = __put_user(data, p);
break;
case TIOCL_GETMOUSEREPORTING:
+ console_lock(); /* May be overkill */
data = mouse_reporting();
+ console_unlock();
ret = __put_user(data, p);
break;
case TIOCL_SETVESABLANK:
+ console_lock();
ret = set_vesa_blanking(p);
+ console_unlock();
break;
case TIOCL_GETKMSGREDIRECT:
data = vt_get_kmsg_redirect();
@@ -2658,13 +2662,21 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
}
break;
case TIOCL_GETFGCONSOLE:
+ /* No locking needed as this is a transiently
+ correct return anyway if the caller hasn't
+ disabled switching */
ret = fg_console;
break;
case TIOCL_SCROLLCONSOLE:
if (get_user(lines, (s32 __user *)(p+4))) {
ret = -EFAULT;
} else {
+ /* Need the console lock here. Note that lots
+ of other calls need fixing before the lock
+ is actually useful ! */
+ console_lock();
scrollfront(vc_cons[fg_console].d, lines);
+ console_unlock();
ret = 0;
}
break;
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index e05094d..c6720be 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -298,9 +298,7 @@ int vt_ioctl(struct tty_struct *tty,
switch (cmd) {
case TIOCLINUX:
- tty_lock();
ret = tioclinux(tty, arg);
- tty_unlock();
break;
case KIOCSOUND:
if (!perm)
next prev parent reply other threads:[~2012-03-02 14:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-02 14:58 [PATCH 0/6] Series short description Alan Cox
2012-03-02 14:59 ` [PATCH 1/6] vt: sort out locking for font handling Alan Cox
2012-03-02 14:59 ` [PATCH 2/6] vt: push down the tty lock so we can see what is left to tackle Alan Cox
2012-03-02 14:59 ` Alan Cox [this message]
2012-03-02 14:59 ` [PATCH 4/6] vt: waitevent is self locked so drop the tty_lock Alan Cox
2012-03-02 15:00 ` [PATCH 5/6] vt: tackle the main part of the selection logic Alan Cox
2012-03-02 15:00 ` [PATCH 6/6] vt: push the tty_lock down into the map handling Alan Cox
2012-03-08 19:14 ` Greg KH
-- strict thread matches above, loose matches on Subject: below --
2012-03-01 19:49 [PATCH 0/6] Remove tty_lock from the console drivers Alan Cox
2012-03-01 19:51 ` [PATCH 3/6] vt: push down tioclinux cases Alan Cox
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