library.h

#ifndef LIBRARY_H_
#define LIBRARY_H_

#include <elf.h>
#include <stdbool.h>
#include <sys/mman.h>
#include <sys/types.h>

#include "maps.h"

#if defined(__x86_64__)
typedef Elf64_Ehdr Elf_Ehdr;
typedef Elf64_Shdr Elf_Shdr;
typedef Elf64_Sym  Elf_Sym;
#elif defined(__i386__)
typedef Elf32_Ehdr Elf_Ehdr;
typedef Elf32_Shdr Elf_Shdr;
typedef Elf32_Sym  Elf_Sym;
#else
#error Unsupported target platform
#endif

struct symbol {
  char *name;
  Elf_Sym sym;
  struct hlist_node symbol_hash;
};

/* Internal data structure for segments. */
struct segment {
  uint64_t addr; /* load addr */
  uint64_t off; /* file offset */
  uint64_t fsz; /* file size */
  uint64_t msz; /* memory size */
  uint64_t type; /* segment type */

  struct list_head section_list;
  struct list_head segments;
};

/* Internal data structure for sections. */
struct section {
  struct segment *seg;  /* containing segment */
  const char *name; /* section name */
  int idx; /* secton index */
  Elf_Shdr shdr; /* section header */
  void *buf;  /* section content */
  uint8_t *pad; /* section padding */
  uint64_t off; /* section offset */
  uint64_t sz;  /* section size */
  uint64_t cap; /* section capacity */
  uint64_t align; /* section alignment */
  uint64_t type;  /* section type */
  uint64_t vma; /* section virtual addr */
  uint64_t lma; /* section load addr */
  uint64_t pad_sz;/* section padding size */
  int loadable; /* whether loadable */
  int pseudo;
  int nocopy;

  struct list_head sections;
  struct list_head seg_entry; /* list of sections in a segment */
  struct hlist_node section_hash;
};

struct library {
  char *pathname;
  bool valid;
  bool vdso;
  char *asr_offset;
  int vsys_offset;
  Elf_Ehdr ehdr;
  struct rb_root rb_region;
  struct hlist_head *section_hash;
  struct hlist_head *symbol_hash;
  char *image;
  size_t image_size;
  struct maps *maps;
  struct hlist_node library_hash;
};

extern char *__kernel_vsyscall;
extern char *__kernel_sigreturn;
extern char *__kernel_rt_sigreturn;

extern void library_init(struct library *, const char *name, struct maps *maps);
extern bool library_parse_elf(struct library *);
extern void library_make_writable(struct library *, bool);
extern void library_patch_syscalls(struct library *);

void patch_syscalls_in_func(char *start, char *end); 

extern void library_patch_syscalls_in_range(struct library *, char *start, char *stop, char **extra_space, int *extra_len);
extern int library_patch_vsyscalls(struct library *);
extern void library_patch_vdso(struct library *, char **space, int *length);

#endif /* LIBRARY_H_ */