Re: [PATCH 1/5 V5] Add a function(ioremap_encrypted) for kdump when AMD sme enabled
From: Borislav Petkov
Date: Tue Jul 03 2018 - 05:39:37 EST
On Tue, Jul 03, 2018 at 10:17:19AM +0800, lijiang wrote:
> for example, the elfcorehdr. In fact, the elfcorehdr and notes
You mean this?
ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
{
- return read_from_oldmem(buf, count, ppos, 0);
+ return read_from_oldmem(buf, count, ppos, 0, sme_active());
That looks encrypted to me.
> call the same function(read_from_oldmem->ioremap_cache), in this case,
> it is very difficult to properly remap the memory if the caller don't
> care whether the memory is encrypted.
So beef up the logic in __ioremap_caller() to figure out based on the
address whether to access the memory encrypted or not. You can find out
the elfcorehdr address in the capture kernel.
--
Regards/Gruss,
Boris.
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