Differential D26323 Diff 76688 head/libexec/rtld-elf/map_object.c

Changeset View

Standalone View

head/libexec/rtld-elf/map_object.c

Show All 34 Lines
#include <stddef.h>		#include <stddef.h>
#include <stdlib.h>		#include <stdlib.h>
#include <string.h>		#include <string.h>
#include <unistd.h>		#include <unistd.h>

#include "debug.h"		#include "debug.h"
#include "rtld.h"		#include "rtld.h"

static Elf_Ehdr get_elf_header(int, const char , const struct stat *);		static Elf_Ehdr get_elf_header(int, const char , const struct stat *,
		Elf_Phdr **phdr);
static int convert_flags(int); /* Elf flags -> mmap flags */		static int convert_flags(int); /* Elf flags -> mmap flags */

int __getosreldate(void);		int __getosreldate(void);

		static bool
		phdr_in_zero_page(const Elf_Ehdr *hdr)
		{
		return (hdr->e_phoff + hdr->e_phnum * sizeof(Elf_Phdr) <
		(size_t)PAGE_SIZE);
		}

/*		/*
* Map a shared object into memory. The "fd" argument is a file descriptor,		* Map a shared object into memory. The "fd" argument is a file descriptor,
* which must be open on the object and positioned at its beginning.		* which must be open on the object and positioned at its beginning.
* The "path" argument is a pathname that is used only for error messages.		* The "path" argument is a pathname that is used only for error messages.
*		*
* The return value is a pointer to a newly-allocated Obj_Entry structure		* The return value is a pointer to a newly-allocated Obj_Entry structure
* for the shared object. Returns NULL on failure.		* for the shared object. Returns NULL on failure.
*/		*/
Show All 34 Lines	map_object(int fd, const char path, const struct stat sb)
Elf_Addr relro_page;		Elf_Addr relro_page;
size_t relro_size;		size_t relro_size;
Elf_Addr note_start;		Elf_Addr note_start;
Elf_Addr note_end;		Elf_Addr note_end;
char *note_map;		char *note_map;
size_t note_map_len;		size_t note_map_len;
Elf_Addr text_end;		Elf_Addr text_end;

hdr = get_elf_header(fd, path, sb);		hdr = get_elf_header(fd, path, sb, &phdr);
if (hdr == NULL)		if (hdr == NULL)
return (NULL);		return (NULL);

/*		/*
* Scan the program header entries, and save key information.		* Scan the program header entries, and save key information.
*
* We expect that the loadable segments are ordered by load address.		* We expect that the loadable segments are ordered by load address.
*/		*/
phdr = (Elf_Phdr )((char )hdr + hdr->e_phoff);
phsize = hdr->e_phnum * sizeof (phdr[0]);		phsize = hdr->e_phnum * sizeof(phdr[0]);
phlimit = phdr + hdr->e_phnum;		phlimit = phdr + hdr->e_phnum;
nsegs = -1;		nsegs = -1;
phdyn = phinterp = phtls = NULL;		phdyn = phinterp = phtls = NULL;
phdr_vaddr = 0;		phdr_vaddr = 0;
relro_page = 0;		relro_page = 0;
relro_size = 0;		relro_size = 0;
note_start = 0;		note_start = 0;
note_end = 0;		note_end = 0;
▲ Show 20 Lines • Show All 210 Lines • ▼ Show 20 Lines	munmap(note_map, note_map_len);
munmap(hdr, PAGE_SIZE);		munmap(hdr, PAGE_SIZE);
return (obj);		return (obj);

error1:		error1:
munmap(mapbase, mapsize);		munmap(mapbase, mapsize);
error:		error:
if (note_map != NULL && note_map != MAP_FAILED)		if (note_map != NULL && note_map != MAP_FAILED)
munmap(note_map, note_map_len);		munmap(note_map, note_map_len);
		if (!phdr_in_zero_page(hdr))
		munmap(phdr, hdr->e_phnum * sizeof(phdr[0]));
munmap(hdr, PAGE_SIZE);		munmap(hdr, PAGE_SIZE);
return (NULL);		return (NULL);
}		}

static Elf_Ehdr *		static Elf_Ehdr *
get_elf_header(int fd, const char path, const struct stat sbp)		get_elf_header(int fd, const char path, const struct stat sbp,
		Elf_Phdr **phdr_p)
{		{
Elf_Ehdr *hdr;		Elf_Ehdr *hdr;
		Elf_Phdr *phdr;

/* Make sure file has enough data for the ELF header */		/* Make sure file has enough data for the ELF header */
if (sbp != NULL && sbp->st_size < (off_t)sizeof(Elf_Ehdr)) {		if (sbp != NULL && sbp->st_size < (off_t)sizeof(Elf_Ehdr)) {
_rtld_error("%s: invalid file format", path);		_rtld_error("%s: invalid file format", path);
return (NULL);		return (NULL);
}		}

hdr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE \| MAP_PREFAULT_READ,		hdr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE \| MAP_PREFAULT_READ,
Show All 32 Lines	get_elf_header(int fd, const char path, const struct stat sbp,
* not strictly required by the ABI specification, but it seems to		* not strictly required by the ABI specification, but it seems to
* always true in practice. And, it simplifies things considerably.		* always true in practice. And, it simplifies things considerably.
*/		*/
if (hdr->e_phentsize != sizeof(Elf_Phdr)) {		if (hdr->e_phentsize != sizeof(Elf_Phdr)) {
_rtld_error(		_rtld_error(
"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);		"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);
goto error;		goto error;
}		}
if (hdr->e_phoff + hdr->e_phnum * sizeof(Elf_Phdr) >		if (phdr_in_zero_page(hdr)) {
(size_t)PAGE_SIZE) {		phdr = (Elf_Phdr )((char )hdr + hdr->e_phoff);
_rtld_error("%s: program header too large", path);		} else {
		phdr = mmap(NULL, hdr->e_phnum * sizeof(phdr[0]),
		PROT_READ, MAP_PRIVATE \| MAP_PREFAULT_READ, fd,
		hdr->e_phoff);
		if (phdr == MAP_FAILED) {
		_rtld_error("%s: error mapping phdr: %s", path,
		rtld_strerror(errno));
goto error;		goto error;
}		}
		}
		*phdr_p = phdr;
return (hdr);		return (hdr);

error:		error:
munmap(hdr, PAGE_SIZE);		munmap(hdr, PAGE_SIZE);
return (NULL);		return (NULL);
}		}

void		void
▲ Show 20 Lines • Show All 83 Lines • Show Last 20 Lines