Messages in this thread | | | Date | Sat, 29 Sep 2018 10:30:52 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v7 RESEND 4/4] kdump/vmcore: support encrypted old memory with SME enabled |
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On Sat, Sep 29, 2018 at 02:24:52PM +0800, lijiang wrote: > At first, i added an input parameter for read_from_oldmem() because of encryption(SME). But > for avoiding to also add the same parameter for copy_oldmem_page(), so i added a new function > copy_oldmem_page_encrypted(). Maybe you had noticed that these functions were very similar.
If you have two very similar functions, you add a *static* workhorse function:
static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, unsigned long offset, int userbuf, bool encrypted)
and you define two wrappers:
copy_oldmem_page() copy_oldmem_page_encrypted()
which both call __copy_oldmem_page() with the appropriate parameters.
But you do *not* do a separate compilation unit just because. None of the reasons you've mentioned warrant having a separate compilation unit while you already have *the* perfect place to put everything - arch/x86/kernel/crash_dump_64.c
> So sorry, here "oldmem encrypted" means the "old memory is encrypted".
I know what it means - I'm trying to explain to you to write it out in plain english and not use some strange constructs like "oldmem encrypted".
A reader would wonder: why is this thing semi-abbreviated and in quotation marks? Does that mean anything special?
Our comments should not be write-only. So after you've written it, try to read it as someone who sees the code for the first time and think hard whether she/he will understand it.
Do you catch my drift now?
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
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