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| author |   Andy Lutomirski <luto@kernel.org> | 2017-03-22 14:32:32 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-03-23 08:25:08 +0100 |
| commit | 23b2a4ddebdd17fad265b4bb77256c2e4ec37dee (patch) | |
| tree | 85f136c21db6fad958224eca963c5ad45a8083ad /arch/x86/kernel/setup.c | |
| parent | x86/efi/32: Fix EFI on systems where the per-cpu GDT is virtually mapped (diff) | |
| download | linux-dev-23b2a4ddebdd17fad265b4bb77256c2e4ec37dee.tar.xz linux-dev-23b2a4ddebdd17fad265b4bb77256c2e4ec37dee.zip | |
x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up
The x86 smpboot trampoline expects initial_page_table to have the
GDT mapped. If the GDT ends up in a virtually mapped per-cpu page,
then it won't be in the page tables at all until perc-pu areas are
set up. The result will be a triple fault the first time that the
CPU attempts to access the GDT after LGDT loads the perc-pu GDT.
This appears to be an old bug, but somehow the GDT fixmap rework
is triggering it. This seems to have something to do with the
memory layout.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/a553264a5972c6a86f9b5caac237470a0c74a720.1490218061.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/setup.c')
| -rw-r--r-- | arch/x86/kernel/setup.c | 15 |
1 files changed, 0 insertions, 15 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 4bf0c8926a1c..56b1177155db 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1226,21 +1226,6 @@ void __init setup_arch(char **cmdline_p) kasan_init(); -#ifdef CONFIG_X86_32 - /* sync back kernel address range */ - clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY, - swapper_pg_dir + KERNEL_PGD_BOUNDARY, - KERNEL_PGD_PTRS); - - /* - * sync back low identity map too. It is used for example - * in the 32-bit EFI stub. - */ - clone_pgd_range(initial_page_table, - swapper_pg_dir + KERNEL_PGD_BOUNDARY, - min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); -#endif - tboot_probe(); map_vsyscall(); |