Messages in this thread Patch in this message | | | Date | Mon, 6 Jul 2015 08:36:19 -0700 | From | tip-bot for Andrey Ryabinin <> | Subject | [tip:x86/urgent] x86/init: Clear 'init_level4_pgt' earlier |
| |
Commit-ID: d0f77d4d04b222a817925d33ba3589b190bfa863 Gitweb: http://git.kernel.org/tip/d0f77d4d04b222a817925d33ba3589b190bfa863 Author: Andrey Ryabinin <a.ryabinin@samsung.com> AuthorDate: Thu, 2 Jul 2015 12:09:33 +0300 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 6 Jul 2015 14:53:13 +0200
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> --- arch/x86/kernel/head64.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 5a46681..65c8985 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];
| |