Messages in this thread | | | Date | Mon, 7 Nov 2022 19:20:34 +0800 | From | Coiby Xu <> | Subject | Re: [RFC v2 4/5] x86/crash: make the page that stores the LUKS volume key inaccessible |
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Hi Dave,
Thanks for the quick review!
On Fri, Nov 04, 2022 at 07:38:17AM -0700, Dave Hansen wrote: >On 11/4/22 04:29, Coiby Xu wrote: >> + if (kexec_crash_image->luks_volume_key_addr) { >> + start = kexec_crash_image->luks_volume_key_addr; >> + end = start + kexec_crash_image->luks_volume_key_sz - 1; >> + page = pfn_to_page(start >> PAGE_SHIFT); >> + nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; >> + set_memory_np((unsigned long)page_address(page), nr_pages); >> + } > >Why does this go pfn -> page -> vaddr? What good does having the page >do?
Sorry it's an imitation of kexec_mark_crashkres.
> Can you just do phys_to_virt() on the start address? Maybe: > > start_paddr = kexec_crash_image->luks_volume_key_addr; > end_paddr = start_paddr + kexec_crash_image->luks_volume_key_sz - 1; > nr_pages = (PAGE_ALIGN(end_paddr) - PAGE_ALIGN_DOWN(start_paddr))/ >PAGE_SIZE; > set_memory_np((unsigned long)phys_to_virt(start_paddr), nr_pages);
Thanks for suggesting a smarter implementation! I'll apply it to next version.
> >Also, if you resend this, please just cc the x86 folks on the series. >The other patches and cover letter have desperately needed context >around this.
Sure, I'll cc the x86 list the complete patch set next time. Sorry you'll have to go to https://lore.kernel.org/lkml/20221104113000.487098-5-coxu@redhat.com/t/ to read related emails for now.
>
-- Best regards, Coiby
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