diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-05-08 17:09:10 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-22 09:17:58 +0100 |
| commit | 60845c87579a51a186868c7a42dd390a10840434 (patch) | |
| tree | b3bfda6ff42b6fbf013b18c47ceb4b2356ac0b3f | |
| parent | 691ac858a381049c3e49d4a84b4d0fa8a1cad201 (diff) | |
x86/boot/32: Fix UP boot on Quark and possibly other platforms
commit d2b6dc61a8dd3c429609b993778cb54e75a5c5f0 upstream.
This partially reverts commit:
23b2a4ddebdd17f ("x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up")
That commit had one definite bug and one potential bug. The
definite bug is that setup_per_cpu_areas() uses a differnet generic
implementation on UP kernels, so initial_page_table never got
resynced. This was fine for access to percpu data (it's in the
identity map on UP), but it breaks other users of
initial_page_table. The potential bug is that helpers like
efi_init() would be called before the tables were synced.
Avoid both problems by just syncing the page tables in setup_arch()
*and* setup_per_cpu_areas().
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
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: 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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/setup.c | 15 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 10 |
2 files changed, 20 insertions, 5 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d1a214287fe3..6b55012d02a3 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1200,6 +1200,21 @@ 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(); diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index bbba27269fdd..f9da471a7707 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -290,11 +290,11 @@ void __init setup_per_cpu_areas(void) #ifdef CONFIG_X86_32 /* - * Sync back kernel address range. We want to make sure that - * all kernel mappings, including percpu mappings, are available - * in the smpboot asm. We can't reliably pick up percpu - * mappings using vmalloc_fault(), because exception dispatch - * needs percpu data. + * Sync back kernel address range again. We already did this in + * setup_arch(), but percpu data also needs to be available in + * the smpboot asm. We can't reliably pick up percpu mappings + * using vmalloc_fault(), because exception dispatch needs + * percpu data. */ clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY, swapper_pg_dir + KERNEL_PGD_BOUNDARY, |