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author | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
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committer | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
commit | 6fb9f3c8a4992f67dcb3ce413df2e22e96b2d400 (patch) | |
tree | 6e3071b2f179a62b027669ac2a238383293bf941 /arch/x86/mm/kasan_init_64.c | |
parent | a126a5e5dc2fcc5cb36af14c89b440cc8e3bab30 (diff) | |
parent | 8b5ab55d254f36e89b1b53aeac7223d2d102483e (diff) |
Merge tag 'v4.4.121' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b2.97-20180331
This is the 4.4.121 stable release
Diffstat (limited to 'arch/x86/mm/kasan_init_64.c')
-rw-r--r-- | arch/x86/mm/kasan_init_64.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 4e5ac46adc9d..fdfa25c83119 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -121,11 +121,22 @@ void __init kasan_init(void) kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END), (void *)KASAN_SHADOW_END); - memset(kasan_zero_page, 0, PAGE_SIZE); - load_cr3(init_level4_pgt); __flush_tlb_all(); - init_task.kasan_depth = 0; + /* + * kasan_zero_page has been used as early shadow memory, thus it may + * contain some garbage. Now we can clear and write protect it, since + * after the TLB flush no one should write to it. + */ + memset(kasan_zero_page, 0, PAGE_SIZE); + for (i = 0; i < PTRS_PER_PTE; i++) { + pte_t pte = __pte(__pa(kasan_zero_page) | __PAGE_KERNEL_RO); + set_pte(&kasan_zero_pte[i], pte); + } + /* Flush TLBs again to be sure that write protection applied. */ + __flush_tlb_all(); + + init_task.kasan_depth = 0; pr_info("KernelAddressSanitizer initialized\n"); } |