* [PATCH] x86, mm: get ASLR work for hugetlb mappings
@ 2013-10-22 13:52 Kirill A. Shutemov
2013-10-22 15:21 ` Dave Hansen
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Kirill A. Shutemov @ 2013-10-22 13:52 UTC (permalink / raw)
To: Andrew Morton, Thomas Gleixner, Ingo Molnar, H. Peter Anvin
Cc: Nadia Yvette Chambers, Naoya Horiguchi, x86, linux-kernel,
linux-mm, Kirill A. Shutemov, Matthew Wilcox
Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
The reason is genereic hugetlb_get_unmapped_area() which is used on
x86-64. It doesn't support randomization and use bottom-up unmapped area
lookup, instead of usual top-down on x86-64.
x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
x86-32.
Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
It fixes the issue and make hugetlb use top-down unmapped area lookup.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
---
arch/x86/include/asm/page.h | 1 +
arch/x86/include/asm/page_32.h | 4 ----
arch/x86/mm/hugetlbpage.c | 9 +++------
3 files changed, 4 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index c87892442e..775873d3be 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -71,6 +71,7 @@ extern bool __virt_addr_valid(unsigned long kaddr);
#include <asm-generic/getorder.h>
#define __HAVE_ARCH_GATE_AREA 1
+#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
#endif /* __KERNEL__ */
#endif /* _ASM_X86_PAGE_H */
diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h
index 4d550d04b6..904f528cc8 100644
--- a/arch/x86/include/asm/page_32.h
+++ b/arch/x86/include/asm/page_32.h
@@ -5,10 +5,6 @@
#ifndef __ASSEMBLY__
-#ifdef CONFIG_HUGETLB_PAGE
-#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
-#endif
-
#define __phys_addr_nodebug(x) ((x) - PAGE_OFFSET)
#ifdef CONFIG_DEBUG_VIRTUAL
extern unsigned long __phys_addr(unsigned long);
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 9d980d88b7..8c9f647ff9 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -87,9 +87,7 @@ int pmd_huge_support(void)
}
#endif
-/* x86_64 also uses this file */
-
-#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+#ifdef CONFIG_HUGETLB_PAGE
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
@@ -99,7 +97,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
info.flags = 0;
info.length = len;
- info.low_limit = TASK_UNMAPPED_BASE;
+ info.low_limit = current->mm->mmap_legacy_base;
info.high_limit = TASK_SIZE;
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
@@ -172,8 +170,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
return hugetlb_get_unmapped_area_topdown(file, addr, len,
pgoff, flags);
}
-
-#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
+#endif /* CONFIG_HUGETLB_PAGE */
#ifdef CONFIG_X86_64
static __init int setup_hugepagesz(char *opt)
--
1.8.4.rc3
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] x86, mm: get ASLR work for hugetlb mappings
2013-10-22 13:52 [PATCH] x86, mm: get ASLR work for hugetlb mappings Kirill A. Shutemov
@ 2013-10-22 15:21 ` Dave Hansen
2013-10-22 17:52 ` Kirill A. Shutemov
2013-11-04 10:41 ` Kirill A. Shutemov
2013-11-11 13:45 ` Kirill A. Shutemov
2 siblings, 1 reply; 6+ messages in thread
From: Dave Hansen @ 2013-10-22 15:21 UTC (permalink / raw)
To: Kirill A. Shutemov, Andrew Morton, Thomas Gleixner, Ingo Molnar,
H. Peter Anvin
Cc: Nadia Yvette Chambers, Naoya Horiguchi, x86, linux-kernel,
linux-mm, Matthew Wilcox
On 10/22/2013 06:52 AM, Kirill A. Shutemov wrote:
> Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> The reason is genereic hugetlb_get_unmapped_area() which is used on
> x86-64. It doesn't support randomization and use bottom-up unmapped area
> lookup, instead of usual top-down on x86-64.
I have to wonder if this was on purpose in order to keep the large and
small mappings separate. We don't *have* to keep them separate this, of
course, but it makes me wonder.
> x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> x86-32.
>
> Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> It fixes the issue and make hugetlb use top-down unmapped area lookup.
Shouldn't we fix the generic code instead of further specializing the
x86 stuff?
In any case, you probably also want to run this through: the
libhugetlbfs tests:
http://sourceforge.net/p/libhugetlbfs/code/ci/master/tree/tests/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86, mm: get ASLR work for hugetlb mappings
2013-10-22 15:21 ` Dave Hansen
@ 2013-10-22 17:52 ` Kirill A. Shutemov
0 siblings, 0 replies; 6+ messages in thread
From: Kirill A. Shutemov @ 2013-10-22 17:52 UTC (permalink / raw)
To: Dave Hansen
Cc: Kirill A. Shutemov, Andrew Morton, Thomas Gleixner, Ingo Molnar,
H. Peter Anvin, Nadia Yvette Chambers, Naoya Horiguchi, x86,
linux-kernel, linux-mm, Matthew Wilcox
Dave Hansen wrote:
> On 10/22/2013 06:52 AM, Kirill A. Shutemov wrote:
> > Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> > The reason is genereic hugetlb_get_unmapped_area() which is used on
> > x86-64. It doesn't support randomization and use bottom-up unmapped area
> > lookup, instead of usual top-down on x86-64.
>
> I have to wonder if this was on purpose in order to keep the large and
> small mappings separate. We don't *have* to keep them separate this, of
> course, but it makes me wonder.
I haven't seen any evidence that it's on purpose, but who knows...
In x86-specific hugetlb_get_unmapped_area() there's explicit check what is
mm->get_unmapped_area top-down or bottom-up, and doing the same.
> > x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> > x86-32.
> >
> > Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> > It fixes the issue and make hugetlb use top-down unmapped area lookup.
>
> Shouldn't we fix the generic code instead of further specializing the
> x86 stuff?
For that we need to modify info.low_limit to mm->mmap_legacy_base (which
is x86 specific, no-go) or switch to top-down and set info.high_limit to
mm->mmap_base.
I don't know how it can affect other architectures.
> In any case, you probably also want to run this through: the
> libhugetlbfs tests:
>
> http://sourceforge.net/p/libhugetlbfs/code/ci/master/tree/tests/
I've got the same fail list for upstream and patched kernel, so no
regression was found.
********** TEST SUMMARY
* 2M
* 32-bit 64-bit
* Total testcases: 107 110
* Skipped: 0 0
* PASS: 98 108
* FAIL: 2 2
* Killed by signal: 7 0
* Bad configuration: 0 0
* Expected FAIL: 0 0
* Unexpected PASS: 0 0
* Strange test result: 0 0
**********
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] x86, mm: get ASLR work for hugetlb mappings
2013-10-22 13:52 [PATCH] x86, mm: get ASLR work for hugetlb mappings Kirill A. Shutemov
2013-10-22 15:21 ` Dave Hansen
@ 2013-11-04 10:41 ` Kirill A. Shutemov
2013-11-04 21:09 ` Andrew Morton
2013-11-11 13:45 ` Kirill A. Shutemov
2 siblings, 1 reply; 6+ messages in thread
From: Kirill A. Shutemov @ 2013-11-04 10:41 UTC (permalink / raw)
To: Andrew Morton
Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
Nadia Yvette Chambers, Naoya Horiguchi, x86, linux-kernel,
linux-mm, Kirill A. Shutemov, Matthew Wilcox
Kirill A. Shutemov wrote:
> Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> The reason is genereic hugetlb_get_unmapped_area() which is used on
> x86-64. It doesn't support randomization and use bottom-up unmapped area
> lookup, instead of usual top-down on x86-64.
>
> x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> x86-32.
>
> Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> It fixes the issue and make hugetlb use top-down unmapped area lookup.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Matthew Wilcox <willy@linux.intel.com>
Andrew, any comments?
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86, mm: get ASLR work for hugetlb mappings
2013-11-04 10:41 ` Kirill A. Shutemov
@ 2013-11-04 21:09 ` Andrew Morton
0 siblings, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2013-11-04 21:09 UTC (permalink / raw)
To: Kirill A. Shutemov
Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
Nadia Yvette Chambers, Naoya Horiguchi, x86, linux-kernel,
linux-mm, Matthew Wilcox
On Mon, 4 Nov 2013 12:41:52 +0200 (EET) "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> wrote:
> Kirill A. Shutemov wrote:
> > Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> > The reason is genereic hugetlb_get_unmapped_area() which is used on
> > x86-64. It doesn't support randomization and use bottom-up unmapped area
> > lookup, instead of usual top-down on x86-64.
> >
> > x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> > x86-32.
> >
> > Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> > It fixes the issue and make hugetlb use top-down unmapped area lookup.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Cc: Matthew Wilcox <willy@linux.intel.com>
>
> Andrew, any comments?
whome? I'm convinced, but it's an x86 patch. I tossed it in there so
it gets a bit of linux-next exposure.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86, mm: get ASLR work for hugetlb mappings
2013-10-22 13:52 [PATCH] x86, mm: get ASLR work for hugetlb mappings Kirill A. Shutemov
2013-10-22 15:21 ` Dave Hansen
2013-11-04 10:41 ` Kirill A. Shutemov
@ 2013-11-11 13:45 ` Kirill A. Shutemov
2 siblings, 0 replies; 6+ messages in thread
From: Kirill A. Shutemov @ 2013-11-11 13:45 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, H. Peter Anvin
Cc: Andrew Morton, Nadia Yvette Chambers, Naoya Horiguchi, x86,
linux-kernel, linux-mm, Matthew Wilcox, Kirill A. Shutemov
On Tue, Oct 22, 2013 at 04:52:20PM +0300, Kirill A. Shutemov wrote:
> Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> The reason is genereic hugetlb_get_unmapped_area() which is used on
> x86-64. It doesn't support randomization and use bottom-up unmapped area
> lookup, instead of usual top-down on x86-64.
>
> x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> x86-32.
>
> Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> It fixes the issue and make hugetlb use top-down unmapped area lookup.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Matthew Wilcox <willy@linux.intel.com>
Gentelmen,
Could you take a look on the patch, please?
It's currently in -mm to get it tested on -next, but it should go through
x86 tree, I believe.
> ---
> arch/x86/include/asm/page.h | 1 +
> arch/x86/include/asm/page_32.h | 4 ----
> arch/x86/mm/hugetlbpage.c | 9 +++------
> 3 files changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
> index c87892442e..775873d3be 100644
> --- a/arch/x86/include/asm/page.h
> +++ b/arch/x86/include/asm/page.h
> @@ -71,6 +71,7 @@ extern bool __virt_addr_valid(unsigned long kaddr);
> #include <asm-generic/getorder.h>
>
> #define __HAVE_ARCH_GATE_AREA 1
> +#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
>
> #endif /* __KERNEL__ */
> #endif /* _ASM_X86_PAGE_H */
> diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h
> index 4d550d04b6..904f528cc8 100644
> --- a/arch/x86/include/asm/page_32.h
> +++ b/arch/x86/include/asm/page_32.h
> @@ -5,10 +5,6 @@
>
> #ifndef __ASSEMBLY__
>
> -#ifdef CONFIG_HUGETLB_PAGE
> -#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
> -#endif
> -
> #define __phys_addr_nodebug(x) ((x) - PAGE_OFFSET)
> #ifdef CONFIG_DEBUG_VIRTUAL
> extern unsigned long __phys_addr(unsigned long);
> diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
> index 9d980d88b7..8c9f647ff9 100644
> --- a/arch/x86/mm/hugetlbpage.c
> +++ b/arch/x86/mm/hugetlbpage.c
> @@ -87,9 +87,7 @@ int pmd_huge_support(void)
> }
> #endif
>
> -/* x86_64 also uses this file */
> -
> -#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
> +#ifdef CONFIG_HUGETLB_PAGE
> static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
> unsigned long addr, unsigned long len,
> unsigned long pgoff, unsigned long flags)
> @@ -99,7 +97,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
>
> info.flags = 0;
> info.length = len;
> - info.low_limit = TASK_UNMAPPED_BASE;
> + info.low_limit = current->mm->mmap_legacy_base;
> info.high_limit = TASK_SIZE;
> info.align_mask = PAGE_MASK & ~huge_page_mask(h);
> info.align_offset = 0;
> @@ -172,8 +170,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> return hugetlb_get_unmapped_area_topdown(file, addr, len,
> pgoff, flags);
> }
> -
> -#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
> +#endif /* CONFIG_HUGETLB_PAGE */
>
> #ifdef CONFIG_X86_64
> static __init int setup_hugepagesz(char *opt)
> --
> 1.8.4.rc3
>
> --
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--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-10-22 13:52 [PATCH] x86, mm: get ASLR work for hugetlb mappings Kirill A. Shutemov
2013-10-22 15:21 ` Dave Hansen
2013-10-22 17:52 ` Kirill A. Shutemov
2013-11-04 10:41 ` Kirill A. Shutemov
2013-11-04 21:09 ` Andrew Morton
2013-11-11 13:45 ` Kirill A. Shutemov
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