This removal should be the last thing done, so that U-Boot does no more memory allocations afterwards, thus avoiding potentially allocating memory which has been freed by a device that fails to de-activate its DMA.
Of course, devices should be marked with DM_FLAG_ACTIVE_DMA or DM_FLAG_OS_PREPARE but this change is good practice, in any case. It also matches the code in announce_and_cleanup(), which we should at some point unify with EFI_LOADER So move the code and add a comment. Note that the TCG2 log is updated after this call, but I cannot see any allocations there. Reported-by: Christian Kohlschütter <christ...@kohlschutter.com> Link: https://lore.kernel.org/u-boot/c101b675-eee6-44cb-8a44-83f72182f...@kohlschutter.com/ Signed-off-by: Simon Glass <s...@chromium.org> --- (no changes since v1) lib/efi_loader/efi_boottime.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index ffe43accd1e..e525662f82f 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -2250,14 +2250,6 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle, list_del(&evt->link); } - if (!efi_st_keep_devices) { - bootm_disable_interrupts(); - if (IS_ENABLED(CONFIG_USB_DEVICE)) - udc_disconnect(); - board_quiesce_devices(); - dm_remove_devices_active(); - } - /* Patch out unsupported runtime function */ efi_runtime_detach(); @@ -2279,6 +2271,19 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle, /* Give the payload some time to boot */ efi_set_watchdog(0); schedule(); + + /* + * this should be the last thing done, to avoid memory allocations + * between removing devices and the OS taking over + */ + if (!efi_st_keep_devices) { + bootm_disable_interrupts(); + if (IS_ENABLED(CONFIG_USB_DEVICE)) + udc_disconnect(); + board_quiesce_devices(); + dm_remove_devices_active(); + } + out: if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) { if (ret != EFI_SUCCESS) -- 2.43.0
