From dabaa4ae32062cb3f3d995e5c63e6cef54ad079b Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Sat, 23 Nov 2024 22:44:05 +0100 Subject: dm: Add dm_remove_devices_active() for ordered device removal This replaces dm_remove_devices_flags() calls in all boot implementations to ensure non vital devices are consistently removed first. All boot implementation except arch/arm/lib/bootm.c currently just call dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL). This can result in crashes when dependencies between devices exists. The driver model's design document describes DM_FLAG_VITAL as "indicates that the device is 'vital' to the operation of other devices". Device removal at boot should follow this. Instead of adding dm_remove_devices_flags() with (DM_REMOVE_ACTIVE_ALL | DM_REMOVE_NON_VITAL) everywhere add dm_remove_devices_active() which does this. Fixes a NULL pointer deref in the apple dart IOMMU driver during EFI boot. The xhci-pci (driver which depends on the IOMMU to work) removes its mapping on removal. This explodes when the IOMMU device was removed first. dm_remove_devices_flags() is kept since it is used for testing of device_remove() calls in dm. Signed-off-by: Janne Grunau --- include/dm/root.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/dm/root.h b/include/dm/root.h index b2f30a842f5..5651b868c8b 100644 --- a/include/dm/root.h +++ b/include/dm/root.h @@ -167,8 +167,18 @@ int dm_uninit(void); * Return: 0 if OK, -ve on error */ int dm_remove_devices_flags(uint flags); + +/** + * dm_remove_devices_active - Call remove function of all active drivers heeding + * device dependencies as far as know, i.e. removing + * devices marked with DM_FLAG_VITAL last. + * + * All active devices will be removed + */ +void dm_remove_devices_active(void); #else static inline int dm_remove_devices_flags(uint flags) { return 0; } +static inline void dm_remove_devices_active(void) { } #endif /** -- cgit v1.2.3