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[PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time

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As it turns out, mapping_info DOES need to be initialized every
time. Without this, page tables were not being corrected updated, which
could cause reboots when a physical address beyond 2G was chosen.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/boot/compressed/pagetable.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/x86/boot/compressed/pagetable.c b/arch/x86/boot/compressed/pagetable.c
index 3c99051566a9..34b95df14e69 100644
--- a/arch/x86/boot/compressed/pagetable.c
+++ b/arch/x86/boot/compressed/pagetable.c
@@ -90,23 +90,17 @@ static void prepare_level4(void)
 }
 
 /*
- * Mapping information structure passed to kernel_ident_mapping_init().
- * Since this never changes, there's no reason to repeatedly fill it
- * in on the stack when calling add_identity_map().
- */
-static struct x86_mapping_info mapping_info = {
-	.alloc_pgt_page	= alloc_pgt_page,
-	.context	= &pgt_data,
-	.pmd_flag	= __PAGE_KERNEL_LARGE_EXEC,
-};
-
-/*
  * Adds the specified range to what will become the new identity mappings.
  * Once all ranges have been added, the new mapping is activated by calling
  * finalize_identity_maps() below.
  */
 void add_identity_map(unsigned long start, unsigned long size)
 {
+	struct x86_mapping_info mapping_info = {
+		.alloc_pgt_page	= alloc_pgt_page,
+		.context	= &pgt_data,
+		.pmd_flag	= __PAGE_KERNEL_LARGE_EXEC,
+	};
 	unsigned long end = start + size;
 
 	/* Make sure we have a top level page table ready to use. */
-- 
2.6.3

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Thread

[PATCH v7 0/9] x86/KASLR: Randomize virtual address separately Kees Cook <keescook@chromium.org> - 2016-05-09 22:30 +0200
  [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Kees Cook <keescook@chromium.org> - 2016-05-09 22:30 +0200
    Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Yinghai Lu <yinghai@kernel.org> - 2016-05-10 00:10 +0200
      Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Yinghai Lu <yinghai@kernel.org> - 2016-05-10 00:30 +0200
      Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Kees Cook <keescook@chromium.org> - 2016-05-10 00:30 +0200
        Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Yinghai Lu <yinghai@kernel.org> - 2016-05-10 00:30 +0200
          Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Ingo Molnar <mingo@kernel.org> - 2016-05-10 08:00 +0200
            Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Borislav Petkov <bp@suse.de> - 2016-05-10 13:30 +0200
      Re: [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Yinghai Lu <yinghai@kernel.org> - 2016-05-10 00:30 +0200
    [tip:x86/boot] x86/KASLR: Initialize mapping_info every time tip-bot for Kees Cook <tipbot@zytor.com> - 2016-05-10 10:50 +0200
  [PATCH v7 8/9] x86/KASLR: Add physical address randomization >4G Kees Cook <keescook@chromium.org> - 2016-05-09 22:30 +0200
  [PATCH v7 2/9] x86/boot: Add missing file header comments Kees Cook <keescook@chromium.org> - 2016-05-09 22:30 +0200
    [tip:x86/boot] x86/boot: Add missing file header comments tip-bot for Kees Cook <tipbot@zytor.com> - 2016-05-10 10:50 +0200

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