arch/x86/include/asm/vdso.h

   1 #ifndef _ASM_X86_VDSO_H
   2 #define _ASM_X86_VDSO_H
   3
   4 #include <asm/page_types.h>
   5 #include <linux/linkage.h>
   6
   7 #ifdef __ASSEMBLER__
   8
   9 #define DEFINE_VDSO_IMAGE(symname, filename)                            \
  10 __PAGE_ALIGNED_DATA ;                                                   \
  11         .globl symname##_start, symname##_end ;                         \
  12         .align PAGE_SIZE ;                                              \
  13         symname##_start: ;                                              \
  14         .incbin filename ;                                              \
  15         symname##_end: ;                                                \
  16         .align PAGE_SIZE /* extra data here leaks to userspace. */ ;    \
  17                                                                         \
  18 .previous ;                                                             \
  19                                                                         \
  20         .globl symname##_pages ;                                        \
  21         .bss ;                                                          \
  22         .align 8 ;                                                      \
  23         .type symname##_pages, @object ;                                \
  24         symname##_pages: ;                                              \
  25         .zero (symname##_end - symname##_start + PAGE_SIZE - 1) / PAGE_SIZE * (BITS_PER_LONG / 8) ; \
  26         .size symname##_pages, .-symname##_pages
  27
  28 #else
  29
  30 #define DECLARE_VDSO_IMAGE(symname)                             \
  31         extern char symname##_start[], symname##_end[];         \
  32         extern struct page *symname##_pages[]
  33
  34 #if defined CONFIG_X86_32 || defined CONFIG_COMPAT
  35
  36 #include <asm/vdso32.h>
  37
  38 DECLARE_VDSO_IMAGE(vdso32_int80);
  39 #ifdef CONFIG_COMPAT
  40 DECLARE_VDSO_IMAGE(vdso32_syscall);
  41 #endif
  42 DECLARE_VDSO_IMAGE(vdso32_sysenter);
  43
  44 /*
  45  * Given a pointer to the vDSO image, find the pointer to VDSO32_name
  46  * as that symbol is defined in the vDSO sources or linker script.
  47  */
  48 #define VDSO32_SYMBOL(base, name)                                       \
  49 ({                                                                      \
  50         extern const char VDSO32_##name[];                              \
  51         (void __user *)(VDSO32_##name + (unsigned long)(base));         \
  52 })
  53 #endif
  54
  55 /*
  56  * These symbols are defined with the addresses in the vsyscall page.
  57  * See vsyscall-sigreturn.S.
  58  */
  59 extern void __user __kernel_sigreturn;
  60 extern void __user __kernel_rt_sigreturn;
  61
  62 void __init patch_vdso32(void *vdso, size_t len);
  63
  64 #endif /* __ASSEMBLER__ */
  65
  66 #endif /* _ASM_X86_VDSO_H */