From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 19 Mar 2018 09:22:57 +0000 (+0100)
Subject: 4.9-stable patches
X-Git-Tag: v4.15.12~28
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=96eb4f55c1ca83cfc0d8b736558011db3092bcdb;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	x86-boot-32-fix-up-boot-on-quark-and-possibly-other-platforms.patch
---

diff --git a/queue-4.9/series b/queue-4.9/series
index 2b8800de6ce..ef3e63f38c4 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -208,3 +208,4 @@ rcutorture-configinit-fix-build-directory-error-message.patch
 locking-locktorture-fix-num-reader-writer-corner-cases.patch
 ima-relax-requiring-a-file-signature-for-new-files-with-zero-length.patch
 net-hns-some-checkpatch.pl-script-warning-fixes.patch
+x86-boot-32-fix-up-boot-on-quark-and-possibly-other-platforms.patch
diff --git a/queue-4.9/x86-boot-32-fix-up-boot-on-quark-and-possibly-other-platforms.patch b/queue-4.9/x86-boot-32-fix-up-boot-on-quark-and-possibly-other-platforms.patch
new file mode 100644
index 00000000000..46a7ee3dcb2
--- /dev/null
+++ b/queue-4.9/x86-boot-32-fix-up-boot-on-quark-and-possibly-other-platforms.patch
@@ -0,0 +1,91 @@
+From d2b6dc61a8dd3c429609b993778cb54e75a5c5f0 Mon Sep 17 00:00:00 2001
+From: Andy Lutomirski <luto@kernel.org>
+Date: Mon, 8 May 2017 17:09:10 -0700
+Subject: x86/boot/32: Fix UP boot on Quark and possibly other platforms
+
+From: Andy Lutomirski <luto@kernel.org>
+
+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>
+
+---
+ arch/x86/kernel/setup.c        |   15 +++++++++++++++
+ arch/x86/kernel/setup_percpu.c |   10 +++++-----
+ 2 files changed, 20 insertions(+), 5 deletions(-)
+
+--- 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();
+--- 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,