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* unexelf.c: Don't assume ElfW (Half) fits in int.

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(entry_address, find_section, unexec): Use ptrdiff_t, not int,
when dealing with ElfW (Half) values, since they can exceed 2**31
on 64-bit OpenBSD hosts.  Problem reported privately by Han Boetes.
(entry_address): Omit unused NUM arg.  All uses changed.
This commit is contained in:
Paul Eggert 2013-05-07 13:55:47 -07:00
parent a261c53eae
commit f269bc61c1
2 changed files with 34 additions and 27 deletions
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8
src/ChangeLog
View file

@ -1,3 +1,11 @@
2013-05-07 Paul Eggert <eggert@cs.ucla.edu>
* unexelf.c: Don't assume ElfW (Half) fits in int.
(entry_address, find_section, unexec): Use ptrdiff_t, not int,
when dealing with ElfW (Half) values, since they can exceed 2**31
on 64-bit OpenBSD hosts. Problem reported privately by Han Boetes.
(entry_address): Omit unused NUM arg. All uses changed.
2013-05-07 Juri Linkov <juri@jurta.org>
* callint.c (Fcall_interactively): Set `visargs[i]' for code 'n'

53
src/unexelf.c
View file

@ -522,12 +522,13 @@ typedef struct {
# define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
#endif
/* The code often converts ElfW (Half) values like e_shentsize to int;
/* The code often converts ElfW (Half) values like e_shentsize to ptrdiff_t;
check that this doesn't lose information. */
#include <intprops.h>
#include <verify.h>
verify ((! TYPE_SIGNED (ElfW (Half)) || INT_MIN <= TYPE_MINIMUM (ElfW (Half)))
&& TYPE_MAXIMUM (ElfW (Half)) <= INT_MAX);
verify ((! TYPE_SIGNED (ElfW (Half))
|| PTRDIFF_MIN <= TYPE_MINIMUM (ElfW (Half)))
&& TYPE_MAXIMUM (ElfW (Half)) <= PTRDIFF_MAX);
#ifdef UNEXELF_DEBUG
# define DEBUG_LOG(expr) fprintf (stderr, #expr " 0x%jx\n", (uintmax_t) (expr))
@ -561,22 +562,18 @@ verify ((! TYPE_SIGNED (ElfW (Half)) || INT_MIN <= TYPE_MINIMUM (ElfW (Half)))
*/
static void *
entry_address (void *section_h, int idx, int num, int entsize)
entry_address (void *section_h, ptrdiff_t idx, ptrdiff_t entsize)
{
char *h = section_h;
ptrdiff_t n = idx;
return h + entsize * n;
return h + idx * entsize;
}
#define OLD_SECTION_H(n) \
(*(ElfW (Shdr) *) entry_address (old_section_h, n, old_file_h->e_shnum, \
old_file_h->e_shentsize))
(*(ElfW (Shdr) *) entry_address (old_section_h, n, old_file_h->e_shentsize))
#define NEW_SECTION_H(n) \
(*(ElfW (Shdr) *) entry_address (new_section_h, n, new_file_h->e_shnum, \
new_file_h->e_shentsize))
(*(ElfW (Shdr) *) entry_address (new_section_h, n, new_file_h->e_shentsize))
#define NEW_PROGRAM_H(n) \
(*(ElfW (Phdr) *) entry_address (new_program_h, n, new_file_h->e_phnum, \
new_file_h->e_phentsize))
(*(ElfW (Phdr) *) entry_address (new_program_h, n, new_file_h->e_phentsize))
#define PATCH_INDEX(n) ((n) += old_bss_index <= (n))
typedef unsigned char byte;
@ -599,12 +596,12 @@ round_up (ElfW (Addr) x, ElfW (Addr) y)
If we don't find the section NAME, that is a fatal error
if NOERROR is false; return -1 if NOERROR is true. */
static int
static ptrdiff_t
find_section (const char *name, const char *section_names, const char *file_name,
ElfW (Ehdr) *old_file_h, ElfW (Shdr) *old_section_h,
bool noerror)
{
int idx;
ptrdiff_t idx;
for (idx = 1; idx < old_file_h->e_shnum; idx++)
{
@ -662,14 +659,15 @@ unexec (const char *new_name, const char *old_name)
ElfW (Off) old_bss_offset;
ElfW (Word) new_data2_incr;
int n, nn;
int old_bss_index, old_sbss_index, old_plt_index;
int old_data_index, new_data2_index;
ptrdiff_t n, nn;
ptrdiff_t old_bss_index, old_sbss_index, old_plt_index;
ptrdiff_t old_data_index, new_data2_index;
#if defined _SYSTYPE_SYSV || defined __sgi
int old_mdebug_index;
ptrdiff_t old_mdebug_index;
#endif
struct stat stat_buf;
off_t old_file_size;
int mask;
/* Open the old file, allocate a buffer of the right size, and read
in the file contents. */
@ -785,7 +783,7 @@ unexec (const char *new_name, const char *old_name)
new_data2_incr = new_data2_size + (new_data2_offset - old_bss_offset);
#ifdef UNEXELF_DEBUG
fprintf (stderr, "old_bss_index %d\n", old_bss_index);
fprintf (stderr, "old_bss_index %td\n", old_bss_index);
DEBUG_LOG (old_bss_addr);
DEBUG_LOG (old_bss_size);
DEBUG_LOG (old_bss_offset);
@ -840,9 +838,9 @@ unexec (const char *new_name, const char *old_name)
#ifdef UNEXELF_DEBUG
DEBUG_LOG (old_file_h->e_shoff);
fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
fprintf (stderr, "Old section count %td\n", (ptrdiff_t) old_file_h->e_shnum);
DEBUG_LOG (new_file_h->e_shoff);
fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
fprintf (stderr, "New section count %td\n", (ptrdiff_t) new_file_h->e_shnum);
#endif
/* Fix up a new program header. Extend the writable data segment so
@ -1089,8 +1087,9 @@ unexec (const char *new_name, const char *old_name)
if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
&& old_mdebug_index != -1)
{
int diff = NEW_SECTION_H (nn).sh_offset
- OLD_SECTION_H (old_mdebug_index).sh_offset;
ptrdiff_t new_offset = NEW_SECTION_H (nn).sh_offset;
ptrdiff_t old_offset = OLD_SECTION_H (old_mdebug_index).sh_offset;
ptrdiff_t diff = new_offset - old_offset;
HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
if (diff)
@ -1170,7 +1169,7 @@ unexec (const char *new_name, const char *old_name)
|| NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
{
ElfW (Shdr) *spt = &NEW_SECTION_H (nn);
unsigned int num = spt->sh_size / spt->sh_entsize;
ptrdiff_t num = spt->sh_size / spt->sh_entsize;
ElfW (Sym) * sym = (ElfW (Sym) *) (NEW_SECTION_H (nn).sh_offset +
new_base);
for (; num--; sym++)
@ -1326,9 +1325,9 @@ unexec (const char *new_name, const char *old_name)
if (stat (new_name, &stat_buf) != 0)
fatal ("Can't stat (%s): %s", new_name, strerror (errno));
n = umask (777);
umask (n);
stat_buf.st_mode |= 0111 & ~n;
mask = umask (777);
umask (mask);
stat_buf.st_mode |= 0111 & ~mask;
if (chmod (new_name, stat_buf.st_mode) != 0)
fatal ("Can't chmod (%s): %s", new_name, strerror (errno));
}