[PATCHv2] sisfb: limit POST memory test according to PCI resource length

[PATCHv2] sisfb: limit POST memory test according to PCI resource length

[Aaro Koskinen]

If the POST memory test fails, the driver may access illegal
memory areas. Instead of hard coding the maximum size, set it
according to the PCI resource length (an additional check is needed in
sisfb_post_map_vram() to ensure it's big enough). DRAM sizing will later
adjust video_size to the correct value.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
---

v2: Add a check to sisfb_post_map_vram().

 drivers/video/sis/sis_main.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c
index b52f8e4..3dde12b 100644
--- a/drivers/video/sis/sis_main.c
+++ b/drivers/video/sis/sis_main.c
@@ -4181,6 +4181,9 @@ static void __devinit
 sisfb_post_map_vram(struct sis_video_info *ivideo, unsigned int *mapsize,
 			unsigned int min)
 {
+	if (*mapsize < (min << 20))
+		return;
+
 	ivideo->video_vbase = ioremap(ivideo->video_base, (*mapsize));
 
 	if(!ivideo->video_vbase) {
@@ -4514,7 +4517,7 @@ sisfb_post_sis300(struct pci_dev *pdev)
 	} else {
 #endif
 		/* Need to map max FB size for finding out about RAM size */
-		mapsize = 64 << 20;
+		mapsize = ivideo->video_size;
 		sisfb_post_map_vram(ivideo, &mapsize, 4);
 
 		if(ivideo->video_vbase) {
@@ -4680,7 +4683,7 @@ sisfb_post_xgi_ramsize(struct sis_video_info *ivideo)
 	orSISIDXREG(SISSR, 0x20, (0x80 | 0x04));
 
 	/* Need to map max FB size for finding out about RAM size */
-	mapsize = 256 << 20;
+	mapsize = ivideo->video_size;
 	sisfb_post_map_vram(ivideo, &mapsize, 32);
 
 	if(!ivideo->video_vbase) {
@@ -5936,6 +5939,7 @@ sisfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 
 	ivideo->video_base = pci_resource_start(pdev, 0);
+	ivideo->video_size = pci_resource_len(pdev, 0);
 	ivideo->mmio_base  = pci_resource_start(pdev, 1);
 	ivideo->mmio_size  = pci_resource_len(pdev, 1);
 	ivideo->SiS_Pr.RelIO = pci_resource_start(pdev, 2) + 0x30;
-- 
1.5.6.5

Re: [PATCHv2] sisfb: limit POST memory test according to PCI resource length

[Paul Mundt]

On Wed, Nov 10, 2010 at 01:04:19PM +0200, Aaro Koskinen wrote:
> If the POST memory test fails, the driver may access illegal
> memory areas. Instead of hard coding the maximum size, set it
> according to the PCI resource length (an additional check is needed in
> sisfb_post_map_vram() to ensure it's big enough). DRAM sizing will later
> adjust video_size to the correct value.
> 
> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Cc: Thomas Winischhofer <thomas@winischhofer.net>
> ---
> 
> v2: Add a check to sisfb_post_map_vram().
> 

Queued for .37, thanks.