[kernel-hardening] Re: [PATCH tip v2] x86/mm: Correct fixmap header usage on adaptable MODULES_END

[Wei Yang <richard.weiyang@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 3466 bytes --]

On Mon, Mar 20, 2017 at 12:40:24PM -0700, Thomas Garnier wrote:
>This patch removes fixmap headers on non-x86 code introduced by the
>adaptable MODULE_END change. It is also removed in the 32-bit pgtable
>header. Instead, it is added  by default in the pgtable generic header
>for both architectures.
>
>Signed-off-by: Thomas Garnier <thgarnie@google.com>
>---
> arch/x86/include/asm/pgtable.h    | 1 +
> arch/x86/include/asm/pgtable_32.h | 1 -
> arch/x86/kernel/module.c          | 1 -
> arch/x86/mm/dump_pagetables.c     | 1 -
> arch/x86/mm/kasan_init_64.c       | 1 -
> mm/vmalloc.c                      | 4 ----
> 6 files changed, 1 insertion(+), 8 deletions(-)
>
>diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
>index 6f6f351e0a81..78d1fc32e947 100644
>--- a/arch/x86/include/asm/pgtable.h
>+++ b/arch/x86/include/asm/pgtable.h
>@@ -598,6 +598,7 @@ pte_t *populate_extra_pte(unsigned long vaddr);
> #include <linux/mm_types.h>
> #include <linux/mmdebug.h>
> #include <linux/log2.h>
>+#include <asm/fixmap.h>
> 
> static inline int pte_none(pte_t pte)
> {
>diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
>index fbc73360aea0..bfab55675c16 100644
>--- a/arch/x86/include/asm/pgtable_32.h
>+++ b/arch/x86/include/asm/pgtable_32.h
>@@ -14,7 +14,6 @@
>  */
> #ifndef __ASSEMBLY__
> #include <asm/processor.h>
>-#include <asm/fixmap.h>
> #include <linux/threads.h>
> #include <asm/paravirt.h>
> 

Yep, I thinks the above two is what I mean.

>diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
>index fad61caac75e..477ae806c2fa 100644
>--- a/arch/x86/kernel/module.c
>+++ b/arch/x86/kernel/module.c
>@@ -35,7 +35,6 @@
> #include <asm/page.h>
> #include <asm/pgtable.h>
> #include <asm/setup.h>
>-#include <asm/fixmap.h>
> 

Hmm... your code is already merged in upstream?

When I look into current Torvalds tree, it looks not include the <asm/fixmap.h>

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/module.c

Which tree your change is based on? Do I miss something?

> #if 0
> #define DEBUGP(fmt, ...)				\
>diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
>index 75efeecc85eb..58b5bee7ea27 100644
>--- a/arch/x86/mm/dump_pagetables.c
>+++ b/arch/x86/mm/dump_pagetables.c
>@@ -20,7 +20,6 @@
> 
> #include <asm/kasan.h>
> #include <asm/pgtable.h>
>-#include <asm/fixmap.h>
> 

The same as this one.

> /*
>  * The dumper groups pagetable entries of the same type into one, and for
>diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
>index 1bde19ef86bd..8d63d7a104c3 100644
>--- a/arch/x86/mm/kasan_init_64.c
>+++ b/arch/x86/mm/kasan_init_64.c
>@@ -9,7 +9,6 @@
> 
> #include <asm/tlbflush.h>
> #include <asm/sections.h>
>-#include <asm/fixmap.h>
> 
> extern pgd_t early_level4_pgt[PTRS_PER_PGD];
> extern struct range pfn_mapped[E820_X_MAX];
>diff --git a/mm/vmalloc.c b/mm/vmalloc.c
>index b7d2a23349f4..0dd80222b20b 100644
>--- a/mm/vmalloc.c
>+++ b/mm/vmalloc.c
>@@ -36,10 +36,6 @@
> #include <asm/tlbflush.h>
> #include <asm/shmparam.h>
> 
>-#ifdef CONFIG_X86
>-# include <asm/fixmap.h>
>-#endif
>-
> #include "internal.h"
> 
> struct vfree_deferred {
>-- 
>2.12.0.367.g23dc2f6d3c-goog


At last, you have tested both on x86-32 and x86-64 platform?

-- 
Wei Yang
Help you, Help me

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]