Prev: cciss: unlock on error path
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From: Alan Cox on 1 Apr 2010 12:40
The virtual console layer uses the BKL for various things that don't really
need it. Clean them out.

Signed-off-by: Alan Cox <alan(a)linux.intel.com>
---

drivers/char/selection.c | 4 ++++
drivers/char/vt.c | 8 +++++---
2 files changed, 9 insertions(+), 3 deletions(-)


diff --git a/drivers/char/selection.c b/drivers/char/selection.c
index f97b9e8..6e79340 100644
--- a/drivers/char/selection.c
+++ b/drivers/char/selection.c
@@ -26,6 +26,7 @@
#include <linux/selection.h>
#include <linux/tiocl.h>
#include <linux/console.h>
+#include <linux/smp_lock.h>

/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
#define isspace(c) ((c) == ' ')
@@ -312,6 +313,8 @@ int paste_selection(struct tty_struct *tty)
struct tty_ldisc *ld;
DECLARE_WAITQUEUE(wait, current);

+ lock_kernel();
+
acquire_console_sem();
poke_blanked_console();
release_console_sem();
@@ -335,5 +338,6 @@ int paste_selection(struct tty_struct *tty)
__set_current_state(TASK_RUNNING);

tty_ldisc_deref(ld);
+ unlock_kernel();
return 0;
}
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index bd1d116..501ca9e 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -282,7 +282,12 @@ static inline unsigned short *screenpos(struct vc_data *vc, int offset, int view

static inline void scrolldelta(int lines)
{
+ lock_kernel();
+ /* FIXME */
+ /* scrolldelta needs some kind of consistency lock, but the BKL was
+ and still is not protecting versus the scheduled back end */
scrollback_delta += lines;
+ unlock_kernel();
schedule_console_callback();
}

@@ -2604,8 +2609,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
return -EFAULT;
ret = 0;

- lock_kernel();
-
switch (type)
{
case TIOCL_SETSEL:
@@ -2680,7 +2683,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
ret = -EINVAL;
break;
}
- unlock_kernel();
return ret;
}


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Prev: cciss: unlock on error path
Next: [COUNTERPATCH] mm: avoid overflowing preempt_count() in mmu_take_all_locks()