Linux Certif

Toute la documentation sur la certification Linux LPI

dl_iterate_phdr

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dl_iterate_phdr - ¶¦Í­¥ª¥Ö¥¸¥§¥¯¥È¤Î¥ê¥¹¥È¤òé¤ë

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#define _GNU_SOURCE

#include <link.h>



int dl_iterate_phdr(

          int (*callback) (struct dl_phdr_info *info,

                           size_t size, void *data),

          void *data);

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³Æ¡¹¤Î callback ¸Æ¤Ó½Ð¤·¤Ï 3 ¤Ä¤Î°ú¤­¿ô¤ò¼õ¤±¼è¤ë: info ¤Ï¶¦Í­¥ª¥Ö¥¸¥§¥¯¥È¤Î¾ðÊó¤òÊÝ»ý¤¹¤ë¹½Â¤ÂΤؤΥݥ¤¥ó¥¿¤Ç¤¢¤ë¡£ size ¤Ï info ¤Ç»Ø¤µ¤ì¤ë¹½Â¤ÂΤΥµ¥¤¥º¤Ç¤¢¤ë¡£ data ¤Ï¸Æ¤Ó½Ð¤·¸µ¥×¥í¥°¥é¥à¤«¤é dl_iterate_phdr() ¤Î¸Æ¤Ó½Ð¤·¤Î (Ʊ¤¸¤¯ data ¤È¤¤¤¦Ì¾Á°¤Î) Âè 2 °ú¤­¿ô¤È¤·¤ÆÅϤµ¤ì¤ëÃͤΥ³¥Ô¡¼¤Ç¤¢¤ë¡£

info °ú¤­¿ô¤Ï¡¢°Ê²¼¤Î¤è¤¦¤Ê·¿¤Î¹½Â¤ÂΤǤ¢¤ë¡£

  struct dl_phdr_info {

    ElfW(Addr)        dlpi_addr;  /* ¥ª¥Ö¥¸¥§¥¯¥È¤Î¥Ù¡¼¥¹¥¢¥É¥ì¥¹ */

    const char       *dlpi_name;  /* (null ʸ»ú¤Ç½ªÃ¼¤µ¤ì¤¿)

                                     ¥ª¥Ö¥¸¥§¥¯¥È̾

    const ElfW(Phdr) *dlpi_phdr;  /* ¤³¤Î¥ª¥Ö¥¸¥§¥¯¥È¤Î

                                     ELF ¥×¥í¥°¥é¥à¥Ø¥Ã¥À¤Î

                                     ÇÛÎó¤Ø¤Î¥Ý¥¤¥ó¥¿ */

    ElfW(Half)        dlpi_phnum; /* 'dlpi_phdr' ¤Î¥¢¥¤¥Æ¥à¿ô */

  };

(ElfW() ¥Þ¥¯¥íÄêµÁ¤Ï°ú¤­¿ô¤ò¥Ï¡¼¥É¥¦¥§¥¢¥¢¡¼¥­¥Æ¥¯¥Á¥ã¤ËŬ¤·¤¿ ELF ¥Ç¡¼¥¿·¿¤Î̾Á°¤ËÊÑ´¹¤¹¤ë¡£ ¤¿¤È¤¨¤Ð¡¢32 ¥Ó¥Ã¥È¥×¥é¥Ã¥È¥Õ¥©¡¼¥à¤Ç¤Ï ElfW(Addr) ¤Ï¥Ç¡¼¥¿·¿Ì¾ Elf32_Addr ¤òÀ¸À®¤¹¤ë¡£ ¤³¤ì¤é¤Î·¿¤Ë¤Ä¤¤¤Æ¤Î¹¹¤Ë¾ÜºÙ¤Ê¾ðÊó¤Ï¡¢¥Ø¥Ã¥À¥Õ¥¡¥¤¥ë <elf.h> ¤È <link.h> ¤Ë¤¢¤ë¡£

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dlpi_phdr ¤È dlpi_phnum ¥Õ¥£¡¼¥ë¥É¤Î°ÕÌ£¤òÍý²ò¤¹¤ë¤Ë¤Ï¡¢ ELF ¶¦Í­¥ª¥Ö¥¸¥§¥¯¥È¤¬´ö¤Ä¤«¤Î¥»¥°¥á¥ó¥È¤«¤é¹½À®¤µ¤ì¤Æ¤¤¤ë¤³¤È¤È¡¢ ³Æ¥»¥°¥á¥ó¥È¤¬¤½¤ì¤ËÂбþ¤¹¤ë¥×¥í¥°¥é¥à¥Ø¥Ã¥À (¤½¤Î¥»¥°¥á¥ó¥È¤òÀâÌÀ¤¹¤ë) ¤ò»ý¤Ã¤Æ¤¤¤ë¤³¤È¤òÃΤäƤ¤¤ëɬÍפ¬¤¢¤ë¡£ dlpi_phdr ¥Õ¥£¡¼¥ë¥É¤Ï¡¢¤³¤Î¶¦Í­¥ª¥Ö¥¸¥§¥¯¥È¤Î¥×¥í¥°¥é¥à¥Ø¥Ã¥À¤ÎÇÛÎó¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç¤¢¤ë¡£ dlpi_phnum ¤Ï¡¢¤³¤ÎÇÛÎó¤Î¥µ¥¤¥º¤òɽ¤¹¡£

¤³¤ì¤é¤Î¥×¥í¥°¥é¥à¥Ø¥Ã¥À¤Ï°Ê²¼¤Î¤è¤¦¤Ê·Á¼°¤Î¹½Â¤ÂΤǤ¢¤ë:

  typedef struct

  {

    Elf32_Word  p_type;    /* ¥»¥°¥á¥ó¥È¤Î·¿ */

    Elf32_Off   p_offset;  /* ¥»¥°¥á¥ó¥È¤Î¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È */

    Elf32_Addr  p_vaddr;   /* ¥»¥°¥á¥ó¥È¤Î²¾ÁÛ¥¢¥É¥ì¥¹ */

    Elf32_Addr  p_paddr;   /* ¥»¥°¥á¥ó¥È¤ÎʪÍý¥¢¥É¥ì¥¹ */

    Elf32_Word  p_filesz;  /* ¥Õ¥¡¥¤¥ë¤Ë¤ª¤±¤ë¥»¥°¥á¥ó¥È¥µ¥¤¥º */

    Elf32_Word  p_memsz;   /* ¥á¥â¥ê¤Ë¤ª¤±¤ë¥»¥°¥á¥ó¥È¥µ¥¤¥º */

    Elf32_Word  p_flags;   /* ¥»¥°¥á¥ó¥È¥Õ¥é¥° */

    Elf32_Word  p_align;   /* ¥»¥°¥á¥ó¥È¤ÎÇÛÃÖ (alignment) */

  } Elf32_Phdr;

ÆÃÄê¤Î¥×¥í¥°¥é¥à¥Ø¥Ã¥À x ¤Î²¾ÁÛ¥á¥â¥ê¤Ë¤ª¤±¤ë°ÌÃ֤ϡ¢°Ê²¼¤Î¼°¤Ç·×»»¤Ç¤­¤ëÅÀ¤ËÃí°Õ¤¹¤ë¤³¤È:

  addr == info->dlpi_addr + info->dlpi_phdr[x].p_vaddr;

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#define _GNU_SOURCE

#include <link.h>

#include <stdlib.h>

#include <stdio.h>



static int

callback(struct dl_phdr_info *info, size_t size, void *data)

{

    int j;



    printf("name=%s (%d segments)\n", info->dlpi_name,

        info->dlpi_phnum);



    for (j = 0; j < info->dlpi_phnum; j++)

         printf("\t\t header %2d: address=%10p\n", j,

             (void *) (info->dlpi_addr + info->dlpi_phdr[j].p_vaddr));

    return 0;

}



int

main(int argc, char *argv[])

{

    dl_iterate_phdr(callback, NULL);



    exit(EXIT_SUCCESS);

}

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