modpost.h

Go to the documentation of this file.

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <elf.h>

#include "elfconfig.h"

#if KERNEL_ELFCLASS == ELFCLASS32

#define Elf_Ehdr    Elf32_Ehdr
#define Elf_Shdr    Elf32_Shdr
#define Elf_Sym     Elf32_Sym
#define Elf_Addr    Elf32_Addr
#define Elf_Sword   Elf64_Sword
#define Elf_Section Elf32_Half
#define ELF_ST_BIND ELF32_ST_BIND
#define ELF_ST_TYPE ELF32_ST_TYPE

#define Elf_Rel     Elf32_Rel
#define Elf_Rela    Elf32_Rela
#define ELF_R_SYM   ELF32_R_SYM
#define ELF_R_TYPE  ELF32_R_TYPE
#else

#define Elf_Ehdr    Elf64_Ehdr
#define Elf_Shdr    Elf64_Shdr
#define Elf_Sym     Elf64_Sym
#define Elf_Addr    Elf64_Addr
#define Elf_Sword   Elf64_Sxword
#define Elf_Section Elf64_Half
#define ELF_ST_BIND ELF64_ST_BIND
#define ELF_ST_TYPE ELF64_ST_TYPE

#define Elf_Rel     Elf64_Rel
#define Elf_Rela    Elf64_Rela
#define ELF_R_SYM   ELF64_R_SYM
#define ELF_R_TYPE  ELF64_R_TYPE
#endif

/* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
typedef struct
{
    Elf32_Word    r_sym;    /* Symbol index */
    unsigned char r_ssym;   /* Special symbol for 2nd relocation */
    unsigned char r_type3;  /* 3rd relocation type */
    unsigned char r_type2;  /* 2nd relocation type */
    unsigned char r_type1;  /* 1st relocation type */
} _Elf64_Mips_R_Info;

typedef union
{
    Elf64_Xword     r_info_number;
    _Elf64_Mips_R_Info  r_info_fields;
} _Elf64_Mips_R_Info_union;

#define ELF64_MIPS_R_SYM(i) \
  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)

#define ELF64_MIPS_R_TYPE(i) \
  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)

#if KERNEL_ELFDATA != HOST_ELFDATA

static inline void __endian(const void *src, void *dest, unsigned int size)
{
    unsigned int i;
    for (i = 0; i < size; i++)
        ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
}

#define TO_NATIVE(x)                        \
({                              \
    typeof(x) __x;                      \
    __endian(&(x), &(__x), sizeof(__x));            \
    __x;                            \
})

#else /* endianness matches */

#define TO_NATIVE(x) (x)

#endif

#define NOFAIL(ptr)   do_nofail((ptr), #ptr)
void *do_nofail(void *ptr, const char *expr);

struct buffer {
    char *p;
    int pos;
    int size;
};

void __attribute__((format(printf, 2, 3)))
buf_printf(struct buffer *buf, const char *fmt, ...);

void
buf_write(struct buffer *buf, const char *s, int len);

struct module {
    struct module *next;
    const char *name;
    int gpl_compatible;
    struct symbol *unres;
    int seen;
    int skip;
    int has_init;
    int has_cleanup;
    struct buffer dev_table_buf;
    char         srcversion[25];
    int is_dot_o;
};

struct elf_info {
    unsigned long size;
    Elf_Ehdr     *hdr;
    Elf_Shdr     *sechdrs;
    Elf_Sym      *symtab_start;
    Elf_Sym      *symtab_stop;
    Elf_Section  export_sec;
    Elf_Section  export_unused_sec;
    Elf_Section  export_gpl_sec;
    Elf_Section  export_unused_gpl_sec;
    Elf_Section  export_gpl_future_sec;
    const char   *strtab;
    char         *modinfo;
    unsigned int modinfo_len;

    /* support for 32bit section numbers */

    unsigned int num_sections; /* max_secindex + 1 */
    unsigned int secindex_strings;
    /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
     * take shndx from symtab_shndx_start[N] instead */
    Elf32_Word   *symtab_shndx_start;
    Elf32_Word   *symtab_shndx_stop;
};

static inline int is_shndx_special(unsigned int i)
{
    return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}

/*
 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
 * the way to -256..-1, to avoid conflicting with real section
 * indices.
 */
#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))

/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(const struct elf_info *info,
                    const Elf_Sym *sym)
{
    if (is_shndx_special(sym->st_shndx))
        return SPECIAL(sym->st_shndx);
    if (sym->st_shndx != SHN_XINDEX)
        return sym->st_shndx;
    return info->symtab_shndx_start[sym - info->symtab_start];
}

/* file2alias.c */
extern unsigned int cross_build;
void handle_moddevtable(struct module *mod, struct elf_info *info,
            Elf_Sym *sym, const char *symname);
void add_moddevtable(struct buffer *buf, struct module *mod);

/* sumversion.c */
void maybe_frob_rcs_version(const char *modfilename,
                char *version,
                void *modinfo,
                unsigned long modinfo_offset);
void get_src_version(const char *modname, char sum[], unsigned sumlen);

/* from modpost.c */
void *grab_file(const char *filename, unsigned long *size);
char* get_next_line(unsigned long *pos, void *file, unsigned long size);
void release_file(void *file, unsigned long size);

void fatal(const char *fmt, ...);
void warn(const char *fmt, ...);
void merror(const char *fmt, ...);