Re: [PATCH] x86/purgatory: Compile purgatory with -D__DISABLE_EXPORTS

[Thomas Huth <thuth@redhat.com>]

On 25/09/2026 21.16, Eric Biggers wrote:
> On Fri, Sep 25, 2026 at 03:01:49PM +0200, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> A previous patch fixed compile-time issues by setting __NO_FORTIFY
>> for all of the purgatory code, but this is insufficient and still
>> leaves build failures that appeared recently in linux-next:
>>
>> ld.lld: error: undefined symbol: __memset
>>>>> referenced by string.c
>>>>>                arch/x86/purgatory/purgatory.ro:(__UNIQUE_ID_addressable___memset_2)
>>
>> ld.lld: error: undefined symbol: __memmove
>>>>> referenced by string.c
>>>>>                arch/x86/purgatory/purgatory.ro:(__UNIQUE_ID_addressable___memmove_3)
>>
>> Set __DISABLE_EXPORTS as well, to avoid pulling in a reference to the
>> wrong string functions.
>>
>> Fixes: 65cbe410d312 ("x86/purgatory: Compile purgatory with -D__NO_FORTIFY")
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>> ---
>>   arch/x86/purgatory/Makefile | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
> 
> I dropped the patch this fixes already, as I mentioned at
> https://lore.kernel.org/linux-crypto/20260924174911.GA1978@sol/ .  It's
> gone from linux-next now.  I think Thomas Huth is planning to send a
> fixed version, together with the two patches that depend on this.
> 
> But compiling all of purgatory (and not just sha256.o as is the status
> quo) with -D__NO_FORTIFY -D__DISABLE_EXPORTS sounds good to me.
Yes, I think that's the way to go, and I've now also verified that the 
change is working. I've now send a new version of the patch here:

  https://lore.kernel.org/lkml/20260928083055.104266-2-thuth@redhat.com/

  Thomas