linux/arch/x86/include/asm/vdso.h
Andy Lutomirski e6577a7ce9 x86, vdso: Move the vvar area before the vdso text
Putting the vvar area after the vdso text is rather complicated: it
only works of the total length of the vdso text mapping is known at
vdso link time, and the linker doesn't allow symbol addresses to
depend on the sizes of non-allocatable data after the PT_LOAD
segment.

Moving the vvar area before the vdso text will allow is to safely
map non-allocatable data after the vdso text, which is a nice
simplification.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/156c78c0d93144ff1055a66493783b9e56813983.1405040914.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-11 16:57:51 -07:00

55 lines
1.2 KiB
C

#ifndef _ASM_X86_VDSO_H
#define _ASM_X86_VDSO_H
#include <asm/page_types.h>
#include <linux/linkage.h>
#include <linux/init.h>
#ifndef __ASSEMBLER__
#include <linux/mm_types.h>
struct vdso_image {
void *data;
unsigned long size; /* Always a multiple of PAGE_SIZE */
/* text_mapping.pages is big enough for data/size page pointers */
struct vm_special_mapping text_mapping;
unsigned long alt, alt_len;
long sym_vvar_start; /* Negative offset to the vvar area */
long sym_vvar_page;
long sym_hpet_page;
long sym_VDSO32_NOTE_MASK;
long sym___kernel_sigreturn;
long sym___kernel_rt_sigreturn;
long sym___kernel_vsyscall;
long sym_VDSO32_SYSENTER_RETURN;
};
#ifdef CONFIG_X86_64
extern const struct vdso_image vdso_image_64;
#endif
#ifdef CONFIG_X86_X32
extern const struct vdso_image vdso_image_x32;
#endif
#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
extern const struct vdso_image vdso_image_32_int80;
#ifdef CONFIG_COMPAT
extern const struct vdso_image vdso_image_32_syscall;
#endif
extern const struct vdso_image vdso_image_32_sysenter;
extern const struct vdso_image *selected_vdso32;
#endif
extern void __init init_vdso_image(const struct vdso_image *image);
#endif /* __ASSEMBLER__ */
#endif /* _ASM_X86_VDSO_H */