lkml.org 
[lkml]   [2017]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 06/18] x86/kasan/64: Teach KASAN about the cpu_entry_area
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.

\
 
 \ /
  Last update: 2017-11-22 16:24    [W:0.069 / U:7.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site