2009-12-25 02:40:47

by Cong Wang

Subject: [Patch] console: limit the range of VGACON_SOFT_SCROLLBACK_SIZE

BuraphaLinux reported that we will trigger a mm warning when
we CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=65536, this is because
mm cann't allocate so many pages. We should limit the range
of CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, don't give a user
any chance to trigger that.

Reported-by: BuraphaLinux Server <[email protected]>
Signed-off-by: WANG Cong <[email protected]>
Cc: David S. Miller <[email protected]>

---
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index fc7d9bb..8e8f18d 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -37,6 +37,7 @@ config VGACON_SOFT_SCROLLBACK
config VGACON_SOFT_SCROLLBACK_SIZE
int "Scrollback Buffer Size (in KB)"
depends on VGACON_SOFT_SCROLLBACK
+ range 1 1024
default "64"
help
Enter the amount of System RAM to allocate for the scrollback

2009-12-25 02:43:09

by Cong Wang

Subject: Re: [Patch] console: limit the range of VGACON_SOFT_SCROLLBACK_SIZE

Adding some Cc's in the original thread. :)

Amerigo Wang wrote:
> BuraphaLinux reported that we will trigger a mm warning when
> we CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=65536, this is because
> mm cann't allocate so many pages. We should limit the range
> of CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, don't give a user
> any chance to trigger that.
>
> Reported-by: BuraphaLinux Server <[email protected]>
> Signed-off-by: WANG Cong <[email protected]>
> Cc: David S. Miller <[email protected]>
>
> ---
> diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
> index fc7d9bb..8e8f18d 100644
> --- a/drivers/video/console/Kconfig
> +++ b/drivers/video/console/Kconfig
> @@ -37,6 +37,7 @@ config VGACON_SOFT_SCROLLBACK
> config VGACON_SOFT_SCROLLBACK_SIZE
> int "Scrollback Buffer Size (in KB)"
> depends on VGACON_SOFT_SCROLLBACK
> + range 1 1024
> default "64"
> help
> Enter the amount of System RAM to allocate for the scrollback

2009-12-25 13:59:14

by Somchai Smythe

Subject: Re: [Patch] console: limit the range of VGACON_SOFT_SCROLLBACK_SIZE

On 12/25/09, Amerigo Wang <[email protected]> wrote:
>
> BuraphaLinux reported that we will trigger a mm warning when
> we CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=65536, this is because
> mm cann't allocate so many pages. We should limit the range
> of CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, don't give a user
> any chance to trigger that.
>
> Reported-by: John Gatewood Ham <[email protected]>
> Signed-off-by: WANG Cong <[email protected]>
> Cc: David S. Miller <[email protected]>
>
> ---
> diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
> index fc7d9bb..8e8f18d 100644
> --- a/drivers/video/console/Kconfig
> +++ b/drivers/video/console/Kconfig
> @@ -37,6 +37,7 @@ config VGACON_SOFT_SCROLLBACK
> config VGACON_SOFT_SCROLLBACK_SIZE
> int "Scrollback Buffer Size (in KB)"
> depends on VGACON_SOFT_SCROLLBACK
> + range 1 1024
> default "64"
> help
> Enter the amount of System RAM to allocate for the scrollback
>

This fixed the problem. Thank you for the fix. I texted on 2.6.32.2
with your patch added, x86_64 kernel.

Tested-by: John Gatewood Ham <[email protected]>