Re: [PATCH 3/4] mm/secretmem: zeroize secret pages before kdump

[David Hildenbrand (Arm)]

On 8/11/26 17:05, Jan Sebastian Götte wrote:
> On 8/11/26 16:53, David Hildenbrand (Arm) wrote:
>> On 7/31/26 18:27, Jan Sebastian Götte wrote:
>>> Register a CRASH_ZEROIZE notifier that wipes secretmem folios. As a
>>> result, when CONFIG_CRASH_ZEROIZE is set, secretmem areas will be
>>> cleared before the kdump kernel is kexec'ed.
>>
>> Are you actually using secretmem in your use case? I heard some rumors that
>> secretmem isn't used all that much in practice :)
> 
> I'm aware nobody is really using secretmem. I decided to build this on top of
> secretmem because it's an existing API that actually kind of fits the use case.
> While I could have added a new API just for this (marking userspace memory as
> wipe-on-crash), making it part of secretmem instead gives some additional
> defense-in-depth protection for both users who only need wiping, and for users
> who only want secretmem's additional protection against kernel memory read
> primitives so I think everyone wins here.

What I was thinking when I looked at patch #3+#4: 50% of the users you add are
irrelevant in practice.

Or are you saying that you are going to start using secretmem for your use case?

-- 
Cheers,

David