* [PATCH] vt: incomplete initialization of vc_tab_stop
@ 2008-10-18 11:49 Wolfgang Kroworsch
2008-10-18 11:57 ` Christoph Hellwig
2008-10-22 10:27 ` Alan Cox
0 siblings, 2 replies; 4+ messages in thread
From: Wolfgang Kroworsch @ 2008-10-18 11:49 UTC (permalink / raw)
To: linux-kernel; +Cc: Alan Cox
Problem 1 (see patch below):
vc_tab_stop is declared as an array of 8 unsigned ints in struct
vc_data in include/linux/console_struct.h .
In drivers/char/vt.c only 5 of these 8 unsigned ints get initialized
leading to unintended tabulator placement on displays with more than
160 columns text.
Problem 2 (open):
Upcoming displays will have more than 256 columns of text leading to
invalid memory access in drivers/char/vt.c during tabulator
calculations:
if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
break;
---
drivers/char/vt.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index d8f83e2..a5af607 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -1644,7 +1644,10 @@ static void reset_terminal(struct vc_data *vc, int do_clear)
vc->vc_tab_stop[1] =
vc->vc_tab_stop[2] =
vc->vc_tab_stop[3] =
- vc->vc_tab_stop[4] = 0x01010101;
+ vc->vc_tab_stop[4] =
+ vc->vc_tab_stop[5] =
+ vc->vc_tab_stop[6] =
+ vc->vc_tab_stop[7] = 0x01010101;
vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
vc->vc_bell_duration = DEFAULT_BELL_DURATION;
@@ -1935,7 +1938,10 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
vc->vc_tab_stop[1] =
vc->vc_tab_stop[2] =
vc->vc_tab_stop[3] =
- vc->vc_tab_stop[4] = 0;
+ vc->vc_tab_stop[4] =
+ vc->vc_tab_stop[5] =
+ vc->vc_tab_stop[6] =
+ vc->vc_tab_stop[7] = 0;
}
return;
case 'm':
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] vt: incomplete initialization of vc_tab_stop
2008-10-18 11:49 [PATCH] vt: incomplete initialization of vc_tab_stop Wolfgang Kroworsch
@ 2008-10-18 11:57 ` Christoph Hellwig
2008-10-22 10:27 ` Alan Cox
1 sibling, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2008-10-18 11:57 UTC (permalink / raw)
To: Wolfgang Kroworsch; +Cc: linux-kernel, Alan Cox
On Sat, Oct 18, 2008 at 01:49:31PM +0200, Wolfgang Kroworsch wrote:
> vc->vc_tab_stop[1] =
> vc->vc_tab_stop[2] =
> vc->vc_tab_stop[3] =
> - vc->vc_tab_stop[4] = 0x01010101;
> + vc->vc_tab_stop[4] =
> + vc->vc_tab_stop[5] =
> + vc->vc_tab_stop[6] =
> + vc->vc_tab_stop[7] = 0x01010101;
>
> + vc->vc_tab_stop[4] =
> + vc->vc_tab_stop[5] =
> + vc->vc_tab_stop[6] =
> + vc->vc_tab_stop[7] = 0;
Using memset might be a beter idea.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] vt: incomplete initialization of vc_tab_stop
2008-10-18 11:49 [PATCH] vt: incomplete initialization of vc_tab_stop Wolfgang Kroworsch
2008-10-18 11:57 ` Christoph Hellwig
@ 2008-10-22 10:27 ` Alan Cox
2008-10-22 18:03 ` Wolfgang Kroworsch
1 sibling, 1 reply; 4+ messages in thread
From: Alan Cox @ 2008-10-22 10:27 UTC (permalink / raw)
To: Wolfgang Kroworsch; +Cc: linux-kernel
On Sat, 18 Oct 2008 13:49:31 +0200
Wolfgang Kroworsch <wolfgang@kroworsch.de> wrote:
> Problem 1 (see patch below):
> vc_tab_stop is declared as an array of 8 unsigned ints in struct
> vc_data in include/linux/console_struct.h .
> In drivers/char/vt.c only 5 of these 8 unsigned ints get initialized
> leading to unintended tabulator placement on displays with more than
> 160 columns text.
Seems sensible enough - but need a Signed-off-by line to apply.
>
> Problem 2 (open):
> Upcoming displays will have more than 256 columns of text leading to
> invalid memory access in drivers/char/vt.c during tabulator
> calculations:
> if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
> break;
Yes. We should either limit the vt size or grow the tables.
Alan
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] vt: incomplete initialization of vc_tab_stop
2008-10-22 10:27 ` Alan Cox
@ 2008-10-22 18:03 ` Wolfgang Kroworsch
0 siblings, 0 replies; 4+ messages in thread
From: Wolfgang Kroworsch @ 2008-10-22 18:03 UTC (permalink / raw)
To: Alan Cox; +Cc: linux-kernel
On Wed, Oct 22, 2008 at 11:27:05AM +0100 Alan Cox wrote:
> On Sat, 18 Oct 2008 13:49:31 +0200 Wolfgang Kroworsch wrote:
>
> > Problem 1 (see patch below):
> > vc_tab_stop is declared as an array of 8 unsigned ints in struct
> > vc_data in include/linux/console_struct.h .
> > In drivers/char/vt.c only 5 of these 8 unsigned ints get initialized
> > leading to unintended tabulator placement on displays with more than
> > 160 columns text.
>
> Seems sensible enough - but need a Signed-off-by line to apply.
Thx, Wolfgang
Signed-off-by: Wolfgang Kroworsch <wolfgang@kroworsch.de>
---
drivers/char/vt.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index d8f83e2..a5af607 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -1644,7 +1644,10 @@ static void reset_terminal(struct vc_data *vc, int do_clear)
vc->vc_tab_stop[1] =
vc->vc_tab_stop[2] =
vc->vc_tab_stop[3] =
- vc->vc_tab_stop[4] = 0x01010101;
+ vc->vc_tab_stop[4] =
+ vc->vc_tab_stop[5] =
+ vc->vc_tab_stop[6] =
+ vc->vc_tab_stop[7] = 0x01010101;
vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
vc->vc_bell_duration = DEFAULT_BELL_DURATION;
@@ -1935,7 +1938,10 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
vc->vc_tab_stop[1] =
vc->vc_tab_stop[2] =
vc->vc_tab_stop[3] =
- vc->vc_tab_stop[4] = 0;
+ vc->vc_tab_stop[4] =
+ vc->vc_tab_stop[5] =
+ vc->vc_tab_stop[6] =
+ vc->vc_tab_stop[7] = 0;
}
return;
case 'm':
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2008-10-22 18:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2008-10-18 11:49 [PATCH] vt: incomplete initialization of vc_tab_stop Wolfgang Kroworsch
2008-10-18 11:57 ` Christoph Hellwig
2008-10-22 10:27 ` Alan Cox
2008-10-22 18:03 ` Wolfgang Kroworsch
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