From f3fa0efce2e765f24356b70bd0786f290d84328c Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sun, 8 Mar 2020 09:08:45 +0100 Subject: [PATCH] efi/libstub/x86: Deal with exit() boot service returning Even though it is uncommon, there are cases where the Exit() EFI boot service might return, e.g., when we were booted via the EFI handover protocol from OVMF and the kernel image was specified on the command line, in which case Exit() attempts to terminate the boot manager, which is not an EFI application itself. So let's drop into an infinite loop instead of randomly executing code that isn't expecting it. Tested-by: Nathan Chancellor # build Signed-off-by: Ard Biesheuvel [ardb: put 'hlt' in deadloop] Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200303080648.21427-1-ardb@kernel.org Link: https://lore.kernel.org/r/20200308080859.21568-15-ardb@kernel.org --- drivers/firmware/efi/libstub/x86-stub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 7f3e97c2aad3..69a942f0640b 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -344,7 +344,8 @@ static void setup_graphics(struct boot_params *boot_params) static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) { efi_bs_call(exit, handle, status, 0, NULL); - unreachable(); + for(;;) + asm("hlt"); } void startup_32(struct boot_params *boot_params);