Messages in this thread Patch in this message | | | Date | Mon, 14 Nov 2022 17:53:43 +0000 | From | Sean Christopherson <> | Subject | Re: [PATCH v2 5/5] x86/kasan: Populate shadow for shared chunk of the CPU entry area |
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On Mon, Nov 14, 2022, Peter Zijlstra wrote: > On Mon, Nov 14, 2022 at 05:44:00PM +0300, Andrey Ryabinin wrote: > > Going back kasan_populate_shadow() seems like safer and easier choice. > > The only disadvantage of it that we might waste 1 page, which is not > > much compared to the KASAN memory overhead. > > So the below delta? > > --- > --- a/arch/x86/mm/kasan_init_64.c > +++ b/arch/x86/mm/kasan_init_64.c > @@ -388,7 +388,7 @@ void __init kasan_init(void) > shadow_cea_end = kasan_mem_to_shadow_align_up(CPU_ENTRY_AREA_BASE + > CPU_ENTRY_AREA_MAP_SIZE); > > - kasan_populate_early_shadow( > + kasan_populate_shadow( > kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM), > kasan_mem_to_shadow((void *)VMALLOC_START));
Wrong one, that's the existing mapping. To get back to v1:
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index af82046348a0..0302491d799d 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -416,8 +416,8 @@ void __init kasan_init(void) * area is randomly placed somewhere in the 512GiB range and mapping * the entire 512GiB range is prohibitively expensive. */ - kasan_populate_early_shadow((void *)shadow_cea_begin, - (void *)shadow_cea_per_cpu_begin); + kasan_populate_shadow(shadow_cea_begin, + shadow_cea_per_cpu_begin, 0); kasan_populate_early_shadow((void *)shadow_cea_end, kasan_mem_to_shadow((void *)__START_KERNEL_map));
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