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author | Alexander Popov <alpopov@ptsecurity.com> | 2015-07-02 12:09:34 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-07-06 14:53:13 +0200 |
commit | 5d5aa3cfca5cf74cd928daf3674642e6004328d1 (patch) | |
tree | 42d53dc7979c3c9141cb7aac20107b9c626ee665 /arch/x86/kernel/head64.c | |
parent | d0f77d4d04b222a817925d33ba3589b190bfa863 (diff) | |
download | lwn-5d5aa3cfca5cf74cd928daf3674642e6004328d1.tar.gz lwn-5d5aa3cfca5cf74cd928daf3674642e6004328d1.zip |
x86/kasan: Fix KASAN shadow region page tables
Currently KASAN shadow region page tables created without
respect of physical offset (phys_base). This causes kernel halt
when phys_base is not zero.
So let's initialize KASAN shadow region page tables in
kasan_early_init() using __pa_nodebug() which considers
phys_base.
This patch also separates x86_64_start_kernel() from KASAN low
level details by moving kasan_map_early_shadow(init_level4_pgt)
into kasan_early_init().
Remove the comment before clear_bss() which stopped bringing
much profit to the code readability. Otherwise describing all
the new order dependencies would be too verbose.
Signed-off-by: Alexander Popov <alpopov@ptsecurity.com>
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: <stable@vger.kernel.org> # 4.0+
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/1435828178-10975-3-git-send-email-a.ryabinin@samsung.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head64.c')
-rw-r--r-- | arch/x86/kernel/head64.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 65c8985e3eb2..f129a9af6357 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -161,13 +161,12 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) /* Kill off the identity-map trampoline */ reset_early_page_tables(); - kasan_map_early_shadow(early_level4_pgt); - - /* clear bss before set_intr_gate with early_idt_handler */ clear_bss(); clear_page(init_level4_pgt); + kasan_early_init(); + 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); @@ -182,8 +181,6 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) /* set init_level4_pgt kernel high mapping*/ init_level4_pgt[511] = early_level4_pgt[511]; - kasan_map_early_shadow(init_level4_pgt); - x86_64_start_reservations(real_mode_data); } |