[PATCH] x86/mm: Simplify p[g4um]d_page() macros

[PATCH] x86/mm: Simplify p[g4um]d_page() macros

[Andi Kleen]

From: Tom Lendacky <thomas.lendacky@amd.com>

[backport of fd7e315988b78 from mainline for stable to fix stable crashes
suggested by Michael Hocko. Should be applied to 4.9 and 4.4.]

Create a pgd_pfn() macro similar to the p[4um]d_pfn() macros and then
use the p[g4um]d_pfn() macros in the p[g4um]d_page() macros instead of
duplicating the code.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/e61eb533a6d0aac941db2723d8aa63ef6b882dee.1500319216.git.thomas.lendacky@amd.com
[Backported to 4.9 stable by AK, suggested by Michael Hocko]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/include/asm/pgtable.h | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 4de6c282c02a..68a55273ce0f 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -173,6 +173,11 @@ static inline unsigned long pud_pfn(pud_t pud)
 	return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
 }
 
+static inline unsigned long pgd_pfn(pgd_t pgd)
+{
+	return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT;
+}
+
 #define pte_page(pte)	pfn_to_page(pte_pfn(pte))
 
 static inline int pmd_large(pmd_t pte)
@@ -578,8 +583,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pmd_page(pmd)		\
-	pfn_to_page((pmd_val(pmd) & pmd_pfn_mask(pmd)) >> PAGE_SHIFT)
+#define pmd_page(pmd)	pfn_to_page(pmd_pfn(pmd))
 
 /*
  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
@@ -647,8 +651,7 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pud_page(pud)		\
-	pfn_to_page((pud_val(pud) & pud_pfn_mask(pud)) >> PAGE_SHIFT)
+#define pud_page(pud)	pfn_to_page(pud_pfn(pud))
 
 /* Find an entry in the second-level page table.. */
 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
@@ -688,7 +691,7 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pgd_page(pgd)		pfn_to_page(pgd_val(pgd) >> PAGE_SHIFT)
+#define pgd_page(pgd)		pfn_to_page(pgd_pfn(pgd))
 
 /* to find an entry in a page-table-directory. */
 static inline unsigned long pud_index(unsigned long address)
-- 
2.17.1

4.4 and 4.9 stable fixes for l1tf patches

[Andi Kleen]

There was a report that syzkaller can causes crashes in 4.4 and 4.9
stable with the L1TF patches applied.

In my tests this is fixed with applying the following backport
from mainline too, as suggested by Michael Hocko.

[PATCH] x86/mm: Simplify p[g4um]d_page() macros

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

Create a pgd_pfn() macro similar to the p[4um]d_pfn() macros and then
use the p[g4um]d_pfn() macros in the p[g4um]d_page() macros instead of
duplicating the code.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/e61eb533a6d0aac941db2723d8aa63ef6b882dee.1500319216.git.thomas.lendacky@amd.com
[Backported to 4.9 stable by AK, suggested by Michael Hocko]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/include/asm/pgtable.h | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 4de6c282c02a..68a55273ce0f 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -173,6 +173,11 @@ static inline unsigned long pud_pfn(pud_t pud)
 	return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
 }
 
+static inline unsigned long pgd_pfn(pgd_t pgd)
+{
+	return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT;
+}
+
 #define pte_page(pte)	pfn_to_page(pte_pfn(pte))
 
 static inline int pmd_large(pmd_t pte)
@@ -578,8 +583,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pmd_page(pmd)		\
-	pfn_to_page((pmd_val(pmd) & pmd_pfn_mask(pmd)) >> PAGE_SHIFT)
+#define pmd_page(pmd)	pfn_to_page(pmd_pfn(pmd))
 
 /*
  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
@@ -647,8 +651,7 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pud_page(pud)		\
-	pfn_to_page((pud_val(pud) & pud_pfn_mask(pud)) >> PAGE_SHIFT)
+#define pud_page(pud)	pfn_to_page(pud_pfn(pud))
 
 /* Find an entry in the second-level page table.. */
 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
@@ -688,7 +691,7 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
  * Currently stuck as a macro due to indirect forward reference to
  * linux/mmzone.h's __section_mem_map_addr() definition:
  */
-#define pgd_page(pgd)		pfn_to_page(pgd_val(pgd) >> PAGE_SHIFT)
+#define pgd_page(pgd)		pfn_to_page(pgd_pfn(pgd))
 
 /* to find an entry in a page-table-directory. */
 static inline unsigned long pud_index(unsigned long address)
-- 
2.17.1

Re: [PATCH] x86/mm: Simplify p[g4um]d_page() macros

[Linus Torvalds]

On Mon, Aug 20, 2018 at 1:37 PM Andi Kleen <andi@firstfloor.org> wrote:
>
> From: Andi Kleen <ak@linux.intel.com>
>
> Create a pgd_pfn() macro similar to the p[4um]d_pfn() macros and then
> use the p[g4um]d_pfn() macros in the p[g4um]d_page() macros instead of
> duplicating the code.

When doing backports, _please_ explicitly specify which commit this is
upstream too.

Also, the original upstream patch is credited to Tom Lendacky.

Or is there something I'm not seeing, and this is different from
commit fd7e315988b7 ("x86/mm: Simplify p[g4um]d_page() macros")?

               Linus

Re: [PATCH] x86/mm: Simplify p[g4um]d_page() macros

[Andi Kleen]

On Mon, Aug 20, 2018 at 02:57:39PM -0700, Linus Torvalds wrote:
> On Mon, Aug 20, 2018 at 1:37 PM Andi Kleen <andi@firstfloor.org> wrote:
> >
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Create a pgd_pfn() macro similar to the p[4um]d_pfn() macros and then
> > use the p[g4um]d_pfn() macros in the p[g4um]d_page() macros instead of
> > duplicating the code.
> 
> When doing backports, _please_ explicitly specify which commit this is
> upstream too.

Ok.

> 
> Also, the original upstream patch is credited to Tom Lendacky.

Okay.

> 
> Or is there something I'm not seeing, and this is different from
> commit fd7e315988b7 ("x86/mm: Simplify p[g4um]d_page() macros")?

No it's Tom's patch just ported to the older tree with some minor
changes. I just fat fingered it while doing the commit

-Andi

Re: [PATCH] x86/mm: Simplify p[g4um]d_page() macros

[Greg KH]

On Mon, Aug 20, 2018 at 03:04:23PM -0700, Andi Kleen wrote:
> On Mon, Aug 20, 2018 at 02:57:39PM -0700, Linus Torvalds wrote:
> > On Mon, Aug 20, 2018 at 1:37 PM Andi Kleen <andi@firstfloor.org> wrote:
> > >
> > > From: Andi Kleen <ak@linux.intel.com>
> > >
> > > Create a pgd_pfn() macro similar to the p[4um]d_pfn() macros and then
> > > use the p[g4um]d_pfn() macros in the p[g4um]d_page() macros instead of
> > > duplicating the code.
> > 
> > When doing backports, _please_ explicitly specify which commit this is
> > upstream too.
> 
> Ok.
> 
> > 
> > Also, the original upstream patch is credited to Tom Lendacky.
> 
> Okay.
> 
> > 
> > Or is there something I'm not seeing, and this is different from
> > commit fd7e315988b7 ("x86/mm: Simplify p[g4um]d_page() macros")?
> 
> No it's Tom's patch just ported to the older tree with some minor
> changes. I just fat fingered it while doing the commit

Ok, I've fixed this up by hand now, please be more careful next time.

greg k-h