alistair23-linux/arch/x86/include/asm/page_32.h

49 lines
1,000 B
C
Raw Normal View History

#ifndef _ASM_X86_PAGE_32_H
#define _ASM_X86_PAGE_32_H
#include <asm/page_32_types.h>
#ifndef __ASSEMBLY__
#define __phys_addr_nodebug(x) ((x) - PAGE_OFFSET)
#ifdef CONFIG_DEBUG_VIRTUAL
extern unsigned long __phys_addr(unsigned long);
#else
#define __phys_addr(x) __phys_addr_nodebug(x)
#endif
#define __phys_addr_symbol(x) __phys_addr(x)
#define __phys_reloc_hide(x) RELOC_HIDE((x), 0)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#endif /* CONFIG_FLATMEM */
#ifdef CONFIG_X86_USE_3DNOW
#include <asm/mmx.h>
[PATCH] vdso: randomize the i386 vDSO by moving it into a vma Move the i386 VDSO down into a vma and thus randomize it. Besides the security implications, this feature also helps debuggers, which can COW a vma-backed VDSO just like a normal DSO and can thus do single-stepping and other debugging features. It's good for hypervisors (Xen, VMWare) too, which typically live in the same high-mapped address space as the VDSO, hence whenever the VDSO is used, they get lots of guest pagefaults and have to fix such guest accesses up - which slows things down instead of speeding things up (the primary purpose of the VDSO). There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support for older glibcs that still rely on a prelinked high-mapped VDSO. Newer distributions (using glibc 2.3.3 or later) can turn this option off. Turning it off is also recommended for security reasons: attackers cannot use the predictable high-mapped VDSO page as syscall trampoline anymore. There is a new vdso=[0|1] boot option as well, and a runtime /proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned on/off. (This version of the VDSO-randomization patch also has working ELF coredumping, the previous patch crashed in the coredumping code.) This code is a combined work of the exec-shield VDSO randomization code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell started this patch and i completed it. [akpm@osdl.org: cleanups] [akpm@osdl.org: compile fix] [akpm@osdl.org: compile fix 2] [akpm@osdl.org: compile fix 3] [akpm@osdl.org: revernt MAXMEM change] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Cc: Gerd Hoffmann <kraxel@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com> Cc: Andi Kleen <ak@muc.de> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 03:53:50 -06:00
static inline void clear_page(void *page)
{
mmx_clear_page(page);
}
static inline void copy_page(void *to, void *from)
{
mmx_copy_page(to, from);
}
#else /* !CONFIG_X86_USE_3DNOW */
#include <linux/string.h>
static inline void clear_page(void *page)
{
memset(page, 0, PAGE_SIZE);
}
static inline void copy_page(void *to, void *from)
{
memcpy(to, from, PAGE_SIZE);
}
#endif /* CONFIG_X86_3DNOW */
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_PAGE_32_H */