Messages in this thread | | | Subject | Re: [PATCH 1/5 V5] Add a function(ioremap_encrypted) for kdump when AMD sme enabled | From | lijiang <> | Date | Tue, 3 Jul 2018 19:44:40 +0800 |
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在 2018年07月03日 19:14, Borislav Petkov 写道: > On Tue, Jul 03, 2018 at 06:58:14PM +0800, lijiang wrote: >> For kdump, the elf header finally use the crash kernel reserved memory, it is not an old memory. > > Lamme repeat my suggestion: > > So beef up the logic in __ioremap_caller() to figure out based on the > address whether to access the memory encrypted or not. In general, you > can deduce, based on the region you're mapping, whether you need to map > in encrypted or decrypted. > > For example: > > addr = elfcorehdr_addr; > > /* Read Elf header */ > rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr); > if (rc < 0) > return rc; > > elfcorehdr_addr has that elfcorehdr address. So you can check which address > you're mapping and do: > > __ioremap_caller: > > ... > prot = __ioremap_compute_prot(...); > > and that __ioremap_compute_prot() function which you will add will have > all that logic to determine encrypted or not by comparing addresses etc. > > Does that make more sense? > Thank you, Boris. Good idea, I will rethink about this issue and post it again.
Regards, Lianbo
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