From b49420d6a1aeb399e5b107fc6eb8584d0860fbd7 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Wed, 21 Aug 2024 15:11:35 -0400 Subject: [PATCH 1588/1625] video/aperture: optionally match the device in sysfb_disable() In aperture_remove_conflicting_pci_devices(), we currently only call sysfb_disable() on vga class devices. This leads to the following problem when the pimary device is not VGA compatible: 1. A PCI device with a non-VGA class is 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 has a VGA class 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 passing a device pointer to sysfb_disable() and checking the device to determine if we should execute it or not. v2: Fix build when CONFIG_SCREEN_INFO is not set v3: Move device check into the mutex Drop primary variable in aperture_remove_conflicting_pci_devices() Drop __init on pci sysfb_pci_dev_is_enabled() Fixes: 5ae3716cfdcd ("video/aperture: Only remove sysfb on the default vga pci device") Cc: Javier Martinez Canillas Cc: Thomas Zimmermann Cc: Helge Deller Cc: Sam Ravnborg Cc: Daniel Vetter Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Reviewed-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Signed-off-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20240821191135.829765-1-alexander.deucher@amd.com --- drivers/video/aperture.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/video/aperture.c b/drivers/video/aperture.c index 561be8feca96..2b5a1e666e9b 100644 --- a/drivers/video/aperture.c +++ b/drivers/video/aperture.c @@ -293,7 +293,7 @@ int aperture_remove_conflicting_devices(resource_size_t base, resource_size_t si * ask for this, so let's assume that a real driver for the display * was already probed and prevent sysfb to register devices later. */ - sysfb_disable(); + sysfb_disable(NULL); aperture_detach_devices(base, size); @@ -346,15 +346,10 @@ EXPORT_SYMBOL(__aperture_remove_legacy_vga_devices); */ int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *name) { - bool primary = false; resource_size_t base, size; int bar, ret = 0; - if (pdev == vga_default_device()) - primary = true; - - if (primary) - sysfb_disable(); + sysfb_disable(&pdev->dev); for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) { if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) @@ -370,7 +365,7 @@ int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *na * that consumes the VGA framebuffer I/O range. Remove this * device as well. */ - if (primary) + if (pdev == vga_default_device()) ret = __aperture_remove_legacy_vga_devices(pdev); return ret; -- 2.52.0