• Alex Deucher's avatar
    video/aperture: optionally match the device in sysfb_disable() · b49420d6
    Alex Deucher authored
    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: 5ae3716c ("video/aperture: Only remove sysfb on the default vga pci device")
    Cc: Javier Martinez Canillas <javierm@redhat.com>
    Cc: Thomas Zimmermann <tzimmermann@suse.de>
    Cc: Helge Deller <deller@gmx.de>
    Cc: Sam Ravnborg <sam@ravnborg.org>
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    Cc: stable@vger.kernel.org
    Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
    Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20240821191135.829765-1-alexander.deucher@amd.com
    b49420d6
aperture.c 11.5 KB