Re: [PATCH] x86/boot/e820: Re-enable fallback if e820 table is empty

[David Gow <david@davidgow.net>]

Le 15/04/2026 à 10:26 PM, Andy Shevchenko a écrit :
> On Wed, Apr 15, 2026 at 09:50:32PM +0800, David Gow wrote:
>> Le 15/04/2026 à 4:51 PM, Andy Shevchenko a écrit :
>>> On Wed, Apr 15, 2026 at 08:30:18AM +0800, David Gow wrote:
> 
> ...
> 
>>>>    	struct boot_e820_entry *entry = entries;
>>>> +	/* If there aren't any entries, we'll want to fall-back to another source. */
>>>> +	if (!nr_entries)
>>>> +		return -1;
>>>
>>> Can we return -ENODATA or -ENOENT here?
>>
>> Sounds like a good idea. The previous code (like this) used -1 for both
>> "there are no entires" and "there are entries which look bogus". Maybe we
>> should replace the latter with -EINVAL, too.
> 
> Maybe, but is it related to (coupled with) this change? If not, we can do it
> later if needed.
> 

I think it's probably related enough: append_e820_table() only has the 
one other error return. That being said, I don't think it matters too 
much either way: there's exactly one caller which checks the return 
value, and it only cares that it's nonzero. We could just replace the 
whole thing with a bool. (Or, if we wanted to be more brave, with the 
count of entries added, though that'd complicate the caller a bit if we 
wanted to preserve the same behaviour.)

Regardless, I've sent out v2 here:
https://lore.kernel.org/all/20260416065746.1896647-1-david@davidgow.net/

Cheers,
-- David