PCI: Prevent restoring assigned resources

restore_dev_resource() copies saved addresses and flags from the struct
pci_dev_resource back to the struct resource, typically, during rollback
from a failure or in preparation for a retry attempt.

If the resource is within resource tree, the resource must not be
modified as the resource tree could be corrupted. Thus, it's a bug to
call restore_dev_resource() for assigned resources (which did happen
due to logic flaws in the BAR resize rollback).

Add WARN_ON_ONCE() into restore_dev_resource() to detect such bugs easily
and return without altering the resource to prevent corruption.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU
Link: https://patch.msgid.link/20251113162628.5946-12-ilpo.jarvinen@linux.intel.com

0 files changed, 0 insertions, 0 deletions