Messages in this thread | | | Date | Mon, 29 Apr 2019 16:12:46 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v3 RESEND 2/2] x86/mm/KASLR: Fix the size of vmemmap section |
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On 04/28/19 at 09:54pm, Kirill A. Shutemov wrote: > > @@ -109,6 +110,14 @@ void __init kernel_randomize_memory(void) > > if (memory_tb < kaslr_regions[0].size_tb) > > kaslr_regions[0].size_tb = memory_tb; > > > > + /** > > Nit: that is weird style for inline comment.
Right, will fix.
Thanks a lot for reviewing.
> > > + * Calculate how many TB vmemmap region needs, and aligned to > > + * 1TB boundary. > > + */ > > + vmemmap_size = (kaslr_regions[0].size_tb << (TB_SHIFT - PAGE_SHIFT)) * > > + sizeof(struct page); > > Hm. Don't we need to take into account alignment requirements for struct > page here? I'm worried about some exotic debug kernel config where > sizeof(struct page) doesn't satify __alignof__(struct page).
I know sizeof(struct page) has handled its own struct alignment and padding. About __alignof__(struct page), will it conflict with below code to convert pfn < -- > page? Not sure if I got your point.
#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
/* memmap is virtually contiguous. */ #define __pfn_to_page(pfn) (vmemmap + (pfn)) #define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
#elif...
> > > + kaslr_regions[2].size_tb = DIV_ROUND_UP(vmemmap_size, 1UL << TB_SHIFT); > > + > > /* Calculate entropy available between regions */ > > remain_entropy = vaddr_end - vaddr_start; > > for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++) > -- > Kirill A. Shutemov
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