Re: [PATCH 1/1] arch/x86: Add better error logging to efi main

[Andre <andre.muller-S0/GAf8tV78@public.gmane.org>]

On Sat, 6 Sep 2014 23:02:51 +0200
Andre <andre.muller-S0/GAf8tV78@public.gmane.org> wrote:
> With a Thinkpad T420 (pre-2.0 EFI), I do run into the failure condition for another reason:
> 
> setup_efi_pci64 gets called,
> the loop therein is executed nr_pci=11 (!?) times.
> The second call run calls into __setup_efi_pci64 successfully, the memcpy takes place; the free_struct: path is not used. Back in setup_efi_pci64, the non-data path is walked.
> 
> For all the other 10 runs of the loop, __setup_efi_pci64 fails at
> if (!pci->romimage || !pci->romsize)
>         return EFI_INVALID_PARAMETER;
> so that is the status here for any run but the second.

Following up with code...

If it is OK to just leave the loop in setup_efi_pci64,
this can be done simply by

--- arch/x86/boot/compressed/eboot.c	2014-09-07 01:54:41.761008645 +0200
+++ arch/x86/boot/compressed/eboot_break.c	2014-09-07 01:52:06.321004951 +0200
@@ -504,6 +504,7 @@
 			params->hdr.setup_data = (unsigned long)rom;
 
 		data = (struct setup_data *)rom;
+		break;
 
 	}
 
But I've got severe doubts about this.

A solution limited to this particular failure mode
could look like the below. It has all the charm of 
introducing a helper var. Hmpf.

--- arch/x86/boot/compressed/eboot.c	2014-09-07 01:54:41.761008645 +0200
+++ arch/x86/boot/compressed/eboot_preserve.c	2014-09-07 01:56:18.529010945 +0200
@@ -474,6 +474,7 @@
 	unsigned long nr_pci;
 	struct setup_data *data;
 	int i;
+	int setup_pci_worked_once = 0;
 
 	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 
@@ -495,7 +496,13 @@
 			continue;
 
 		status = __setup_efi_pci64(pci, &rom);
-		if (status != EFI_SUCCESS)
+		if (status == EFI_SUCCESS)
+			setup_pci_worked_once = 1;
+		else if (status == EFI_INVALID_PARAMETER && setup_pci_worked_once == 1 && i == nr_pci - 1) {
+			status = EFI_SUCCESS;
+			continue;
+		}
+		else if (status != EFI_SUCCESS)
 			continue;
 
 		if (data)



Regards,
Andre