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authorAndrey Ryabinin <a.ryabinin@samsung.com>2015-07-02 12:09:33 +0300
committerIngo Molnar <mingo@kernel.org>2015-07-06 14:53:13 +0200
commitd0f77d4d04b222a817925d33ba3589b190bfa863 (patch)
treeecf9850be071f9a35852baa471d1d6b7b5c52401 /arch/x86
parent5aac644a9944bea93b4f05ced1883a902a2535f6 (diff)
x86/init: Clear 'init_level4_pgt' earlier
Currently x86_64_start_kernel() has two KASAN related function calls. The first call maps shadow to early_level4_pgt, the second maps shadow to init_level4_pgt. If we move clear_page(init_level4_pgt) earlier, we could hide KASAN low level detail from generic x86_64 initialization code. The next patch will do it. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: <stable@vger.kernel.org> # 4.0+ Cc: Alexander Popov <alpopov@ptsecurity.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1435828178-10975-2-git-send-email-a.ryabinin@samsung.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/head64.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 5a4668136e98..65c8985e3eb2 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -166,6 +166,8 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
/* clear bss before set_intr_gate with early_idt_handler */
clear_bss();
+ clear_page(init_level4_pgt);
+
for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
set_intr_gate(i, early_idt_handler_array[i]);
load_idt((const struct desc_ptr *)&idt_descr);
@@ -177,7 +179,6 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
*/
load_ucode_bsp();
- clear_page(init_level4_pgt);
/* set init_level4_pgt kernel high mapping*/
init_level4_pgt[511] = early_level4_pgt[511];