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/*
* $Header: /var/cvsroot/gentoo-projects/pax-utils/paxelf.h,v 1.23 2005/05/24 22:01:22 vapier Exp $
* Make sure all of the common elf stuff is setup as we expect
*/
#ifndef _PAX_ELF_H
#define _PAX_ELF_H
#include <sys/mman.h>
#ifdef __linux__
# include <elf.h>
# include <asm/elf.h>
# include <byteswap.h>
#else
# include <sys/elf_common.h>
#endif
extern char do_reverse_endian;
/* Get a value 'X' in the elf header, compensating for endianness. */
#define EGET(X) \
(__extension__ ({ \
uint64_t __res; \
if (!do_reverse_endian) { __res = (X); \
} else if (sizeof(X) == 1) { __res = (X); \
} else if (sizeof(X) == 2) { __res = bswap_16((X)); \
} else if (sizeof(X) == 4) { __res = bswap_32((X)); \
} else if (sizeof(X) == 8) { __res = bswap_64((X)); \
} else { \
fprintf(stderr, "EGET failed ;(\n"); \
exit(EXIT_FAILURE); \
} \
__res; \
}))
/* Set a value 'Y' in the elf header to 'X', compensating for endianness. */
#define ESET(Y,X) \
do if (!do_reverse_endian) { Y = (X); \
} else if (sizeof(Y) == 1) { Y = (X); \
} else if (sizeof(Y) == 2) { Y = bswap_16((uint16_t)(X)); \
} else if (sizeof(Y) == 4) { Y = bswap_32((uint32_t)(X)); \
} else if (sizeof(Y) == 8) { Y = bswap_64((uint64_t)(X)); \
} else { \
fprintf(stderr, "ESET failed ;(\n")); \
exit(EXIT_FAILURE); \
} while (0)
typedef struct {
void *ehdr;
void *phdr;
void *shdr;
char *data;
char elf_class;
off_t len;
int fd;
} elfobj;
#define EHDR32(ptr) ((Elf32_Ehdr *)(ptr))
#define EHDR64(ptr) ((Elf64_Ehdr *)(ptr))
#define PHDR32(ptr) ((Elf32_Phdr *)(ptr))
#define PHDR64(ptr) ((Elf64_Phdr *)(ptr))
#define SHDR32(ptr) ((Elf32_Shdr *)(ptr))
#define SHDR64(ptr) ((Elf64_Shdr *)(ptr))
#define DYN32(ptr) ((Elf32_Dyn *)(ptr))
#define DYN64(ptr) ((Elf64_Dyn *)(ptr))
#define SYM32(ptr) ((Elf32_Sym *)(ptr))
#define SYM64(ptr) ((Elf64_Sym *)(ptr))
/* prototypes */
extern char *pax_short_hf_flags(unsigned long flags);
extern char *pax_short_pf_flags(unsigned long flags);
extern char *gnu_short_stack_flags(unsigned long flags);
extern elfobj *readelf(const char *filename);
extern void unreadelf(elfobj *elf);
extern const char *get_elfeitype(elfobj *elf, int ei_type, int type);
extern const char *get_elfetype(elfobj *elf);
extern const char *get_elfemtype(int type);
extern const char *get_elfptype(int type);
extern const char *get_elfdtype(int type);
extern const char *get_elfstttype(int type);
extern void *elf_findsecbyname(elfobj *elf, const char *name);
/* helper functions for showing errors */
#define warn(fmt, args...) \
fprintf(stderr, "%s: " fmt "\n", argv0, ## args)
#define warnf(fmt, args...) warn("%s(): " fmt, __FUNCTION__, ## args)
#define err(fmt, args...) \
do { \
warn(fmt, ## args); \
exit(EXIT_FAILURE); \
} while (0)
/* PaX flags (to be read in elfhdr.e_flags) */
#define HF_PAX_PAGEEXEC 1 /* 0: Paging based non-exec pages */
#define HF_PAX_EMUTRAMP 2 /* 0: Emulate trampolines */
#define HF_PAX_MPROTECT 4 /* 0: Restrict mprotect() */
#define HF_PAX_RANDMMAP 8 /* 0: Randomize mmap() base */
#define HF_PAX_RANDEXEC 16 /* 1: Randomize ET_EXEC base */
#define HF_PAX_SEGMEXEC 32 /* 0: Segmentation based non-exec pages */
#define EI_PAX 14 /* Index in e_ident[] where to read flags */
#define __PAX_FLAGS(B, elf) \
((EHDR ## B (elf->ehdr)->e_ident[EI_PAX + 1] << 8) + EHDR ## B (elf->ehdr)->e_ident[EI_PAX])
#define PAX_FLAGS(elf) \
(__extension__ ({ \
unsigned long __res; \
if (elf->elf_class == ELFCLASS32) \
__res = __PAX_FLAGS(32, elf); \
else \
__res = __PAX_FLAGS(64, elf); \
__res; \
}))
/*
* in case we are not defined by proper/up-to-date system headers,
* we check for a bunch of PT_GNU defines and custom PAX ones
*/
#ifndef PT_GNU_STACK
# define PT_GNU_STACK 0x6474e551
#endif
/* not in <=binutils-2.14.90.0.8 (should come in by way of .9) */
#ifndef PT_GNU_RELRO
# define PT_GNU_RELRO 0x6474e552
#endif
/*
* propably will never be official added to the toolchain.
* But none the less we should try to get 0x65041580 reserved
*/
#ifndef PT_PAX_FLAGS
# define PT_PAX_FLAGS 0x65041580
# define PF_PAGEEXEC (1 << 4) /* Enable PAGEEXEC */
# define PF_NOPAGEEXEC (1 << 5) /* Disable PAGEEXEC */
# define PF_SEGMEXEC (1 << 6) /* Enable SEGMEXEC */
# define PF_NOSEGMEXEC (1 << 7) /* Disable SEGMEXEC */
# define PF_MPROTECT (1 << 8) /* Enable MPROTECT */
# define PF_NOMPROTECT (1 << 9) /* Disable MPROTECT */
# define PF_RANDEXEC (1 << 10) /* Enable RANDEXEC */
# define PF_NORANDEXEC (1 << 11) /* Disable RANDEXEC */
# define PF_EMUTRAMP (1 << 12) /* Enable EMUTRAMP */
# define PF_NOEMUTRAMP (1 << 13) /* Disable EMUTRAMP */
# define PF_RANDMMAP (1 << 14) /* Enable RANDMMAP */
# define PF_NORANDMMAP (1 << 15) /* Disable RANDMMAP */
#endif /* PT_PAX_ */
/* older glibc/uclibc will need this */
#ifndef EM_ST19
# define EM_ST19 74
#endif
#endif /* _PAX_ELF_H */
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