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Do not export PAGE_SIZE to userspace.

PATCH In review Kirill A. Shutemov 2 participants 4 messages Oct 23, 2007

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Kirill A. Shutemov

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#0 lore raw

PATCH 1/1 Do not export PAGE_SIZE to userspace.

Userspace should use getpagesize() or sysconf(_SC_PAGESIZE) to get memory page size.

man 2 getpagesize:
... Generally, one uses binaries that are architecture but not machine model dependent, in order to have a single binary distribution per architecture. This means that a user program should not find PAGE_SIZE at compile time from a header file, but use an actual system call, at least for those architectures (like sun4) where this dependency exists.

Signed-off-by Kirill A. Shutemov <[email protected]>
---
 include/asm-blackfin/page.h |    4 ++--
 include/asm-m32r/page.h     |    3 ++-
 include/asm-ppc/page.h      |    4 ++--
 include/asm-s390/page.h     |    2 +-
 include/asm-sh64/page.h     |    2 +-
 include/asm-um/page.h       |    4 ++++
 include/asm-x86/page_32.h   |    3 ++-
 include/asm-x86/page_64.h   |    3 ++-
 8 files changed, 16 insertions(+), 9 deletions(-)
include/asm-blackfin/page.h +2 -2
index 8bc8671..613d353 100644
@@ -1,6 +1,8 @@
 #ifndef _BLACKFIN_PAGE_H
 #define _BLACKFIN_PAGE_H
 
+#ifdef __KERNEL__
+
 /* PAGE_SHIFT determines the page size */
 
 #define PAGE_SHIFT	12

@@ -11,8 +13,6 @@
 #endif
 #define PAGE_MASK	(~(PAGE_SIZE-1))
 
-#ifdef __KERNEL__
-
 #include <asm/setup.h>
 
 #ifndef __ASSEMBLY__
include/asm-m32r/page.h +2 -1
index 04fd183..7246369 100644
@@ -1,12 +1,13 @@
 #ifndef _ASM_M32R_PAGE_H
 #define _ASM_M32R_PAGE_H
 
+#ifdef __KERNEL__
+
 /* PAGE_SHIFT determines the page size */
 #define PAGE_SHIFT	12
 #define PAGE_SIZE	(1UL << PAGE_SHIFT)
 #define PAGE_MASK	(~(PAGE_SIZE-1))
 
-#ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
 extern void clear_page(void *to);
include/asm-ppc/page.h +2 -2
index ad4c5a1..a1333a0 100644
@@ -1,6 +1,8 @@
 #ifndef _PPC_PAGE_H
 #define _PPC_PAGE_H
 
+#ifdef __KERNEL__
+
 #include <asm/asm-compat.h>
 
 /* PAGE_SHIFT determines the page size */

@@ -13,8 +15,6 @@
  */
 #define PAGE_MASK	(~((1 << PAGE_SHIFT) - 1))
 
-#ifdef __KERNEL__
-
 /* This must match what is in arch/ppc/Makefile */
 #define PAGE_OFFSET	CONFIG_KERNEL_START
 #define KERNELBASE	PAGE_OFFSET
include/asm-s390/page.h +1 -1
index 584d0ee..160293c 100644
@@ -9,6 +9,7 @@
 #ifndef _S390_PAGE_H
 #define _S390_PAGE_H
 
+#ifdef __KERNEL__
 #include <linux/const.h>
 #include <asm/types.h>
 

@@ -19,7 +20,6 @@
 #define PAGE_DEFAULT_ACC	0
 #define PAGE_DEFAULT_KEY	(PAGE_DEFAULT_ACC << 4)
 
-#ifdef __KERNEL__
 #include <asm/setup.h>
 #ifndef __ASSEMBLY__
include/asm-sh64/page.h +1 -1
index 472089a..d1c3fa2 100644
@@ -17,6 +17,7 @@
  *
  */
 
+#ifdef __KERNEL__
 
 /* PAGE_SHIFT determines the page size */
 #define PAGE_SHIFT	12

@@ -43,7 +44,6 @@
 #define ARCH_HAS_SETCLEAR_HUGE_PTE
 #endif
 
-#ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
 extern struct page *mem_map;
include/asm-um/page.h +4 -0
index 4b424c7..85604ae 100644
@@ -7,6 +7,8 @@
 #ifndef __UM_PAGE_H
 #define __UM_PAGE_H
 
+#ifdef __KERNEL__
+
 struct page;
 
 #include <linux/types.h>

@@ -118,4 +120,6 @@ extern struct page *arch_validate(struct page *page, gfp_t mask, int order);
 #include <asm-generic/memory_model.h>
 #include <asm-generic/page.h>
 
+#endif /* __KERNEL__ */
+
 #endif
include/asm-x86/page_32.h +2 -1
index 80ecc66..2569e21 100644
@@ -1,6 +1,8 @@
 #ifndef _I386_PAGE_H
 #define _I386_PAGE_H
 
+#ifdef __KERNEL__
+
 /* PAGE_SHIFT determines the page size */
 #define PAGE_SHIFT	12
 #define PAGE_SIZE	(1UL << PAGE_SHIFT)

@@ -9,7 +11,6 @@
 #define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
 #define LARGE_PAGE_SIZE (1UL << PMD_SHIFT)
 
-#ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
 #ifdef CONFIG_X86_USE_3DNOW
include/asm-x86/page_64.h +2 -1
index c3b52bc..80ab148 100644
@@ -1,6 +1,8 @@
 #ifndef _X86_64_PAGE_H
 #define _X86_64_PAGE_H
 
+#ifdef __KERNEL__
+
 #include <linux/const.h>
 
 /* PAGE_SHIFT determines the page size */

@@ -37,7 +39,6 @@
 #define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
 extern unsigned long end_pfn;
Signature · 4 lines
Regards,  Kirill A. Shutemov
 + Belarus, Minsk
 + Velesys LLC, http://www.velesys.com/
 + ALT Linux Team, http://www.altlinux.com/
#1 lore raw
Quoted 2 lines · Kirill A. Shutemov

Userspace should use getpagesize() or sysconf(_SC_PAGESIZE) to get memory page size.

please go back through the archives and read the history here. we should work at dropping page.h completely, not making it an empty file.
-mike

author
#2 lore raw
Quoted 7 lines · Mike Frysinger
Quoted 2 lines · Kirill A. Shutemov

Userspace should use getpagesize() or sysconf(_SC_PAGESIZE) to get memory page size.

please go back through the archives and read the history here. we should work at dropping page.h completely, not making it an empty file.

Do you mean page.h shouldn't be exported to userspace or should be dropped from kernelspace too?

Signature · 4 lines
Regards,  Kirill A. Shutemov
 + Belarus, Minsk
 + Velesys LLC, http://www.velesys.com/
 + ALT Linux Team, http://www.altlinux.com/
#3 lore raw
Quoted 10 lines · Kirill A. Shutemov
Quoted 7 lines · Mike Frysinger
Quoted 2 lines · Kirill A. Shutemov

Userspace should use getpagesize() or sysconf(_SC_PAGESIZE) to get memory page size.

please go back through the archives and read the history here. we should work at dropping page.h completely, not making it an empty file.

Do you mean page.h shouldn't be exported to userspace

yes

Quoted 1 line

or should be dropped from kernelspace too?

noooooooooooooooooo

;)
-mike