[PATCH] video/aperture: match the pci device when calling sysfb_disable()
Alex Deucher
alexander.deucher at amd.com
Fri Aug 9 15:03:27 UTC 2024
In aperture_remove_conflicting_pci_devices(), match the pci
device determine whether or not to call sysfb_disable(). This
fixes cases where the pimary device is not VGA compatible which
leads to the following problem:
1. A PCI device with a non-VGA class is the the boot display
2. That device is probed first and it is not a vga device so
sysfb_disable() is not called, but the device resources
are freed by aperture_detach_platform_device()
3. Non-primary GPU is vga device and it ends up calling sysfb_disable()
4. NULL pointer dereference via sysfb_disable() since the resources
have already been freed by aperture_detach_platform_device() when
it was called by the other device.
Fix this by calling sysfb_disable() on the device associated with it.
Fixes: 5ae3716cfdcd ("video/aperture: Only remove sysfb on the default vga pci device")
Cc: Javier Martinez Canillas <javierm at redhat.com>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Helge Deller <deller at gmx.de>
Cc: Sam Ravnborg <sam at ravnborg.org>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
---
drivers/video/aperture.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/video/aperture.c b/drivers/video/aperture.c
index 561be8feca96..56a5a0bc2b1a 100644
--- a/drivers/video/aperture.c
+++ b/drivers/video/aperture.c
@@ -6,6 +6,7 @@
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
+#include <linux/screen_info.h>
#include <linux/slab.h>
#include <linux/sysfb.h>
#include <linux/types.h>
@@ -346,6 +347,7 @@ EXPORT_SYMBOL(__aperture_remove_legacy_vga_devices);
*/
int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *name)
{
+ struct screen_info *si = &screen_info;
bool primary = false;
resource_size_t base, size;
int bar, ret = 0;
@@ -353,7 +355,7 @@ int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *na
if (pdev == vga_default_device())
primary = true;
- if (primary)
+ if (pdev == screen_info_pci_dev(si))
sysfb_disable();
for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) {
--
2.45.2
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