Messages in this thread | | | From | Andy Lutomirski <> | Date | Wed, 22 Nov 2017 07:22:28 -0800 | Subject | Re: [PATCH v2 06/18] x86/kasan/64: Teach KASAN about the cpu_entry_area |
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On Wed, Nov 22, 2017 at 1:05 AM, Andrey Ryabinin <aryabinin@virtuozzo.com> wrote: > > > On 11/22/2017 07:44 AM, Andy Lutomirski wrote: >> The cpu_entry_area will contain stacks. Make sure that KASAN has >> appropriate shadow mappings for them. >> >> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> >> Cc: Alexander Potapenko <glider@google.com> >> Cc: Dmitry Vyukov <dvyukov@google.com> >> Cc: kasan-dev@googlegroups.com >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> --- >> arch/x86/mm/kasan_init_64.c | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c >> index 99dfed6dfef8..43d376687315 100644 >> --- a/arch/x86/mm/kasan_init_64.c >> +++ b/arch/x86/mm/kasan_init_64.c >> @@ -330,7 +330,14 @@ void __init kasan_init(void) >> early_pfn_to_nid(__pa(_stext))); >> >> kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END), >> - (void *)KASAN_SHADOW_END); >> + kasan_mem_to_shadow((void *)(__fix_to_virt(FIX_CPU_ENTRY_AREA_BOTTOM)))); >> + >> + kasan_populate_shadow((unsigned long)kasan_mem_to_shadow((void *)(__fix_to_virt(FIX_CPU_ENTRY_AREA_BOTTOM))), >> + (unsigned long)kasan_mem_to_shadow((void *)(__fix_to_virt(FIX_CPU_ENTRY_AREA_TOP) + PAGE_SIZE)), > > What's '+ PAGE_SIZE' for? >
__fix_to_virt(..._TOP) returns the address of the *bottom* of the last cpu_entry_area page. +PAGE_SIZE returns one past the end of the region, which I assume is the correct thing to pass.
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