Re: tty-related oops in latest kernel(s)?

[Antonino A. Daplas]

On Wed, 2007-05-30 at 19:01 +0300, Tero Roponen wrote:
> On Wed, 30 May 2007, Andrew Morton wrote:
> 
> > On Wed, 30 May 2007 15:02:49 +0300 (EEST) Tero Roponen <teanropo@xxxxxx> wrote:
> > 
> > > On Wed, 30 May 2007, Pekka Enberg wrote:
> > > 
> > > > On 5/30/07, Tero Roponen <teanropo@xxxxxx> wrote:

> [root@terrop ~]# cat oops.c
> #include <sys/ioctl.h>
> #include <stdio.h>
> #include <linux/fb.h>
> #include <fcntl.h>
> 
> int main(void)
> {
>         struct fb_var_screeninfo fbinfo;
>         int fd = open("/dev/fb0", O_RDWR);
>         if (fd < 0)
>                 return 1;
> 
>         /* Get screeninfo */
>         ioctl(fd, FBIOGET_VSCREENINFO, &fbinfo);
> 
>         /* Change depth from current 16 to 24. */
>         fbinfo.bits_per_pixel = 24;
>         ioctl(fd, FBIOPUT_VSCREENINFO, &fbinfo);
> 
>         return 0;
> }
> 
> So this seems to be a framebuffer error.

It's a fb_setcolreg() bug in neofb.  Try this patch?

Tony


neofb: Fix pseudo_palette array overrun in neofb_setcolreg

The pseudo_palette has room for 16 entries only, but in truecolor mode, it
attempts to add 256.

Signed-off-by: Antonino Daplas <adaplas@xxxxxxxxx>
---

 drivers/video/neofb.c |   30 ++++++++++++++++--------------
 1 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/video/neofb.c b/drivers/video/neofb.c
index bd30aba..731d7a5 100644
--- a/drivers/video/neofb.c
+++ b/drivers/video/neofb.c
@@ -1286,34 +1286,36 @@ static int neofb_setcolreg(u_int regno, 
 	if (regno >= fb->cmap.len || regno > 255)
 		return -EINVAL;
 
-	switch (fb->var.bits_per_pixel) {
-	case 8:
+	if (fb->var.bits_per_pixel <= 8) {
 		outb(regno, 0x3c8);
 
 		outb(red >> 10, 0x3c9);
 		outb(green >> 10, 0x3c9);
 		outb(blue >> 10, 0x3c9);
-		break;
-	case 16:
-		((u32 *) fb->pseudo_palette)[regno] =
+	} else if (regno < 16) {
+		switch (fb->var.bits_per_pixel) {
+		case 16:
+			((u32 *) fb->pseudo_palette)[regno] =
 				((red & 0xf800)) | ((green & 0xfc00) >> 5) |
 				((blue & 0xf800) >> 11);
-		break;
-	case 24:
-		((u32 *) fb->pseudo_palette)[regno] =
+			break;
+		case 24:
+			((u32 *) fb->pseudo_palette)[regno] =
 				((red & 0xff00) << 8) | ((green & 0xff00)) |
 				((blue & 0xff00) >> 8);
-		break;
+			break;
 #ifdef NO_32BIT_SUPPORT_YET
-	case 32:
-		((u32 *) fb->pseudo_palette)[regno] =
+		case 32:
+			((u32 *) fb->pseudo_palette)[regno] =
 				((transp & 0xff00) << 16) | ((red & 0xff00) << 8) |
 				((green & 0xff00)) | ((blue & 0xff00) >> 8);
-		break;
+			break;
 #endif
-	default:
-		return 1;
+		default:
+			return 1;
+		}
 	}
+
 	return 0;
 }