[PATCH 01/11] Initialize the mapping of KASan shadow memory
From: linux@armlinux.org.uk (Russell King - ARM Linux)
Date: 2017-10-19 12:03:07
Also in:
linux-mm, lkml
On Thu, Oct 12, 2017 at 02:42:49AM +0300, Dmitry Osipenko wrote:
On 11.10.2017 11:22, Abbott Liu wrote:quoted
+void __init kasan_map_early_shadow(pgd_t *pgdp) +{ + int i; + unsigned long start = KASAN_SHADOW_START; + unsigned long end = KASAN_SHADOW_END; + unsigned long addr; + unsigned long next; + pgd_t *pgd; + + for (i = 0; i < PTRS_PER_PTE; i++) + set_pte_at(&init_mm, KASAN_SHADOW_START + i*PAGE_SIZE, + &kasan_zero_pte[i], pfn_pte( + virt_to_pfn(kasan_zero_page), + __pgprot(_L_PTE_DEFAULT | L_PTE_DIRTY | L_PTE_XN)));Shouldn't all __pgprot's contain L_PTE_MT_WRITETHROUGH ?
One of the architecture restrictions is that the cache attributes of all aliases should match (but there is a specific workaround that permits this, provided that the dis-similar mappings aren't accessed without certain intervening instructions.) Why should it be L_PTE_MT_WRITETHROUGH, and not the same cache attributes as the lowmem mapping? -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up