[PATCH 2/5] x86_64: kasan: flush tlbs after switching cr3

Andrey Ryabinin
2015-06-30T09:00:41Z

load_cr3() doesn't cause tlb_flush if PGE enabled.
This may cause tons of false positive reports spamming
kernel to death.
To fix this __flush_tlb_all() should be called explicitly
after cr3 changed.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: <stable@vger.kernel.org> # 4.0
---
arch/x86/mm/kasan_init_64.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index 0e4a05f..5d26642 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -208,6 +208,7 @@ void __init kasan_init(void)

memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
load_cr3(early_level4_pgt);
+ __flush_tlb_all();

clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);

@@ -234,5 +235,6 @@ void __init kasan_init(void)
memset(kasan_zero_page, 0, PAGE_SIZE);

load_cr3(init_level4_pgt);
+ __flush_tlb_all();
init_task.kasan_depth = 0;
}
--
2.4.4