return result;
}
-/* Read AMOUNT bytes from PTR and store them in VAL as an unsigned value.
- Checks to make sure that the read will not reach or pass END
- and that VAL is big enough to hold AMOUNT bytes. */
-#define SAFE_BYTE_GET(VAL, PTR, AMOUNT, END) \
- do \
- { \
- unsigned int amount = (AMOUNT); \
- if (sizeof (VAL) < amount) \
- { \
+/* Read AMOUNT bytes from PTR and store them in VAL.
+ Checks to make sure that the read will not reach or pass END.
+ FUNC chooses whether the value read is unsigned or signed, and may
+ be either byte_get or byte_get_signed. If INC is true, PTR is
+ incremented after reading the value.
+ This macro cannot protect against PTR values derived from user input.
+ The C standard sections 6.5.6 and 6.5.8 say attempts to do so using
+ pointers is undefined behaviour. */
+#define SAFE_BYTE_GET_INTERNAL(VAL, PTR, AMOUNT, END, FUNC, INC) \
+ do \
+ { \
+ size_t amount = (AMOUNT); \
+ if (sizeof (VAL) < amount) \
+ { \
error (ngettext ("internal error: attempt to read %d byte " \
"of data in to %d sized variable", \
"internal error: attempt to read %d bytes " \
"of data in to %d sized variable", \
amount), \
- amount, (int) sizeof (VAL)); \
- amount = sizeof (VAL); \
- } \
- if ((PTR) >= (END) - amount) \
- { \
- if ((PTR) < (END)) \
- amount = (END) - (PTR); \
- else \
- amount = 0; \
- } \
- if (amount == 0 || amount > 8) \
- VAL = 0; \
- else \
- VAL = byte_get ((PTR), amount); \
- } \
+ (int) amount, (int) sizeof (VAL)); \
+ amount = sizeof (VAL); \
+ } \
+ assert ((PTR) <= (END)); \
+ size_t avail = (END) - (PTR); \
+ if (amount > avail) \
+ amount = avail; \
+ if (amount == 0) \
+ (VAL) = 0; \
+ else \
+ (VAL) = (FUNC) ((PTR), amount); \
+ if (INC) \
+ (PTR) += amount; \
+ } \
while (0)
-/* Like SAFE_BYTE_GET, but also increments PTR by AMOUNT. */
+#define SAFE_BYTE_GET(VAL, PTR, AMOUNT, END) \
+ SAFE_BYTE_GET_INTERNAL (VAL, PTR, AMOUNT, END, byte_get, false)
+
#define SAFE_BYTE_GET_AND_INC(VAL, PTR, AMOUNT, END) \
- do \
- { \
- SAFE_BYTE_GET (VAL, PTR, AMOUNT, END); \
- PTR += AMOUNT; \
- } \
- while (0)
+ SAFE_BYTE_GET_INTERNAL (VAL, PTR, AMOUNT, END, byte_get, true)
-/* Like SAFE_BYTE_GET, but reads a signed value. */
#define SAFE_SIGNED_BYTE_GET(VAL, PTR, AMOUNT, END) \
- do \
- { \
- unsigned int amount = (AMOUNT); \
- if ((PTR) >= (END) - amount) \
- { \
- if ((PTR) < (END)) \
- amount = (END) - (PTR); \
- else \
- amount = 0; \
- } \
- if (amount) \
- VAL = byte_get_signed ((PTR), amount); \
- else \
- VAL = 0; \
- } \
- while (0)
+ SAFE_BYTE_GET_INTERNAL (VAL, PTR, AMOUNT, END, byte_get_signed, false)
-/* Like SAFE_SIGNED_BYTE_GET, but also increments PTR by AMOUNT. */
#define SAFE_SIGNED_BYTE_GET_AND_INC(VAL, PTR, AMOUNT, END) \
- do \
- { \
- SAFE_SIGNED_BYTE_GET (VAL, PTR, AMOUNT, END); \
- PTR += AMOUNT; \
- } \
- while (0)
+ SAFE_BYTE_GET_INTERNAL (VAL, PTR, AMOUNT, END, byte_get_signed, true)
typedef struct State_Machine_Registers
{
unsigned char discriminant;
unsigned int bytes_read;
- SAFE_BYTE_GET (discriminant, data, 1, end);
+ SAFE_BYTE_GET_AND_INC (discriminant, data, 1, end);
-- uvalue;
- data ++;
assert (uvalue > 0);
switch (discriminant)
/* Read the first 4 bytes. For a 32-bit DWARF section, this
will be the length. For a 64-bit DWARF section, it'll be
the escape code 0xffffffff followed by an 8 byte length. */
- SAFE_BYTE_GET (length, section_begin, 4, end);
+ SAFE_BYTE_GET_AND_INC (length, section_begin, 4, end);
if (length == 0xffffffff)
- {
- SAFE_BYTE_GET (length, section_begin + 4, 8, end);
- section_begin += length + 12;
- }
+ SAFE_BYTE_GET_AND_INC (length, section_begin, 8, end);
else if (length >= 0xfffffff0 && length < 0xffffffff)
{
warn (_("Reserved length value (0x%s) found in section %s\n"),
dwarf_vmatoa ("x", length), section->name);
return false;
}
- else
- section_begin += length + 4;
/* Negative values are illegal, they may even cause infinite
looping. This can happen if we can't accurately apply
relocations to an object file, or if the file is corrupt. */
- if ((signed long) length <= 0 || section_begin < start)
+ if (length > (size_t) (end - section_begin))
{
warn (_("Corrupt unit length (0x%s) found in section %s\n"),
dwarf_vmatoa ("x", length), section->name);
return false;
}
+ section_begin += length;
}
if (num_units == 0)
for (namei = 0; namei < name_count; ++namei)
{
uint64_t string_offset, entry_offset;
+ unsigned char *p;
- SAFE_BYTE_GET (string_offset,
- name_table_string_offsets + namei * offset_size,
- offset_size, unit_end);
- SAFE_BYTE_GET (entry_offset,
- name_table_entry_offsets + namei * offset_size,
- offset_size, unit_end);
+ p = name_table_string_offsets + namei * offset_size;
+ SAFE_BYTE_GET (string_offset, p, offset_size, unit_end);
+ p = name_table_entry_offsets + namei * offset_size;
+ SAFE_BYTE_GET (entry_offset, p, offset_size, unit_end);
printf ("[%3u] #%08x %s:", namei, hash_table_hashes[namei],
fetch_indirect_string (string_offset));
return 0;
}
- SAFE_BYTE_GET (version, phdr, 4, limit);
+ phash = phdr;
+ SAFE_BYTE_GET_AND_INC (version, phash, 4, limit);
if (version >= 2)
- SAFE_BYTE_GET (ncols, phdr + 4, 4, limit);
- SAFE_BYTE_GET (nused, phdr + 8, 4, limit);
- SAFE_BYTE_GET (nslots, phdr + 12, 4, limit);
+ SAFE_BYTE_GET_AND_INC (ncols, phash, 4, limit);
+ SAFE_BYTE_GET_AND_INC (nused, phash, 4, limit);
+ SAFE_BYTE_GET_AND_INC (nslots, phash, 4, limit);
- phash = phdr + 16;
pindex = phash + (size_t) nslots * 8;
ppool = pindex + (size_t) nslots * 4;
{
for (j = 0; j < ncols; j++)
{
- SAFE_BYTE_GET (dw_sect, ppool + j * 4, 4, limit);
+ unsigned char *p = ppool + j * 4;
+ SAFE_BYTE_GET (dw_sect, p, 4, limit);
printf (" %8s", get_DW_SECT_short_name (dw_sect));
}
printf ("\n");
i, dwarf_vmatoa ("x", signature));
for (j = 0; j < ncols; j++)
{
- SAFE_BYTE_GET (val, prow + j * 4, 4, limit);
+ unsigned char *p = prow + j * 4;
+ SAFE_BYTE_GET (val, p, 4, limit);
if (do_display)
printf (" %8d", val);
else
{
- SAFE_BYTE_GET (dw_sect, ppool + j * 4, 4, limit);
+ p = ppool + j * 4;
+ SAFE_BYTE_GET (dw_sect, p, 4, limit);
/* PR 17531: file: 10796eb3. */
if (dw_sect >= DW_SECT_MAX)
for (j = 0; j < ncols; j++)
{
- SAFE_BYTE_GET (val, ppool + j * 4, 4, limit);
+ unsigned char *p = ppool + j * 4;
+ SAFE_BYTE_GET (val, p, 4, limit);
if (do_display)
printf (" %8s", get_DW_SECT_short_name (val));
}
for (j = 0; j < ncols; j++)
{
- SAFE_BYTE_GET (val, prow + j * 4, 4, limit);
+ unsigned char *p = prow + j * 4;
+ SAFE_BYTE_GET (val, p, 4, limit);
if (do_display)
printf (" %8d", val);
else
{
- SAFE_BYTE_GET (dw_sect, ppool + j * 4, 4, limit);
+ p = ppool + j * 4;
+ SAFE_BYTE_GET (dw_sect, p, 4, limit);
if (dw_sect >= DW_SECT_MAX)
warn (_("Overlarge Dwarf section index detected: %u\n"), dw_sect);
else
projects / binutils-gdb.git / commitdiff