FreeChainXenon/binutils-gdb
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

gdb: change functions returning value contents to use gdb::array_view

Browse source 
The bug fixed by this [1] patch was caused by an out-of-bounds access to
a value's content.  The code gets the value's content (just a pointer)
and then indexes it with a non-sensical index.

This made me think of changing functions that return value contents to
return array_views instead of a plain pointer.  This has the advantage
that when GDB is built with _GLIBCXX_DEBUG, accesses to the array_view
are checked, making bugs more apparent / easier to find.

This patch changes the return types of these functions, and updates
callers to call .data() on the result, meaning it's not changing
anything in practice.  Additional work will be needed (which can be done
little by little) to make callers propagate the use of array_view and
reap the benefits.

[1] https://sourceware.org/pipermail/gdb-patches/2021-September/182306.html

Change-Id: I5151f888f169e1c36abe2cbc57620110673816f3
This commit is contained in:
Simon Marchi 2021-10-04 20:47:06 -04:00
parent d9f82e9313
commit 50888e42dc
96 changed files with 453 additions and 417 deletions
Download patch file Download diff file Expand all files Collapse all files

54
gdb/ada-lang.c
View file

@ -2181,7 +2181,7 @@ decode_constrained_packed_array (struct value *arr)
bounds may be variable and were not passed to that function. So,
we further resolve the array bounds here and then update the
sizes. */
const gdb_byte *valaddr = value_contents_for_printing (arr);
const gdb_byte *valaddr = value_contents_for_printing (arr).data ();
CORE_ADDR address = value_address (arr);
gdb::array_view<const gdb_byte> view
= gdb::make_array_view (valaddr, TYPE_LENGTH (type));
@ -2438,7 +2438,7 @@ ada_value_primitive_packed_val (struct value *obj, const gdb_byte *valaddr,
if (obj == NULL)
src = valaddr + offset;
else
src = value_contents (obj) + offset;
src = value_contents (obj).data () + offset;
if (is_dynamic_type (type))
{
@ -2488,7 +2488,7 @@ ada_value_primitive_packed_val (struct value *obj, const gdb_byte *valaddr,
else
{
v = allocate_value (type);
src = value_contents (obj) + offset;
src = value_contents (obj).data () + offset;
}
if (obj != NULL)
@ -2511,7 +2511,7 @@ ada_value_primitive_packed_val (struct value *obj, const gdb_byte *valaddr,
}
else
set_value_bitsize (v, bit_size);
unpacked = value_contents_writeable (v);
unpacked = value_contents_writeable (v).data ();
if (bit_size == 0)
{
@ -2581,12 +2581,13 @@ ada_value_assign (struct value *toval, struct value *fromval)
if (is_big_endian && is_scalar_type (value_type (fromval)))
from_offset = from_size - bits;
copy_bitwise (buffer, value_bitpos (toval),
value_contents (fromval), from_offset,
value_contents (fromval).data (), from_offset,
bits, is_big_endian);
write_memory_with_notification (to_addr, buffer, len);
val = value_copy (toval);
memcpy (value_contents_raw (val), value_contents (fromval),
memcpy (value_contents_raw (val).data (),
value_contents (fromval).data (),
TYPE_LENGTH (type));
deprecated_set_value_type (val, type);
@ -2634,14 +2635,16 @@ value_assign_to_component (struct value *container, struct value *component,
= TYPE_LENGTH (value_type (component)) * TARGET_CHAR_BIT - bits;
else
src_offset = 0;
copy_bitwise (value_contents_writeable (container) + offset_in_container,
copy_bitwise ((value_contents_writeable (container).data ()
+ offset_in_container),
value_bitpos (container) + bit_offset_in_container,
value_contents (val), src_offset, bits, 1);
value_contents (val).data (), src_offset, bits, 1);
}
else
copy_bitwise (value_contents_writeable (container) + offset_in_container,
copy_bitwise ((value_contents_writeable (container).data ()
+ offset_in_container),
value_bitpos (container) + bit_offset_in_container,
value_contents (val), 0, bits, 0);
value_contents (val).data (), 0, bits, 0);
}
/* Determine if TYPE is an access to an unconstrained array. */
@ -4010,7 +4013,7 @@ ensure_lval (struct value *val)
VALUE_LVAL (val) = lval_memory;
set_value_address (val, addr);
write_memory (addr, value_contents (val), len);
write_memory (addr, value_contents (val).data (), len);
}
return val;
@ -4181,8 +4184,8 @@ ada_convert_actual (struct value *actual, struct type *formal_type0)
actual_type = ada_check_typedef (value_type (actual));
val = allocate_value (actual_type);
memcpy ((char *) value_contents_raw (val),
(char *) value_contents (actual),
memcpy ((char *) value_contents_raw (val).data (),
(char *) value_contents (actual).data (),
TYPE_LENGTH (actual_type));
actual = ensure_lval (val);
}
@ -4245,11 +4248,13 @@ make_array_descriptor (struct type *type, struct value *arr)
for (i = ada_array_arity (ada_check_typedef (value_type (arr)));
i > 0; i -= 1)
{
modify_field (value_type (bounds), value_contents_writeable (bounds),
modify_field (value_type (bounds),
value_contents_writeable (bounds).data (),
ada_array_bound (arr, i, 0),
desc_bound_bitpos (bounds_type, i, 0),
desc_bound_bitsize (bounds_type, i, 0));
modify_field (value_type (bounds), value_contents_writeable (bounds),
modify_field (value_type (bounds),
value_contents_writeable (bounds).data (),
ada_array_bound (arr, i, 1),
desc_bound_bitpos (bounds_type, i, 1),
desc_bound_bitsize (bounds_type, i, 1));
@ -4258,14 +4263,14 @@ make_array_descriptor (struct type *type, struct value *arr)
bounds = ensure_lval (bounds);
modify_field (value_type (descriptor),
value_contents_writeable (descriptor),
value_contents_writeable (descriptor).data (),
value_pointer (ensure_lval (arr),
desc_type->field (0).type ()),
fat_pntr_data_bitpos (desc_type),
fat_pntr_data_bitsize (desc_type));
modify_field (value_type (descriptor),
value_contents_writeable (descriptor),
value_contents_writeable (descriptor).data (),
value_pointer (bounds,
desc_type->field (1).type ()),
fat_pntr_bounds_bitpos (desc_type),
@ -6553,7 +6558,8 @@ ada_value_primitive_field (struct value *arg1, int offset, int fieldno,
int bit_pos = TYPE_FIELD_BITPOS (arg_type, fieldno);
int bit_size = TYPE_FIELD_BITSIZE (arg_type, fieldno);
return ada_value_primitive_packed_val (arg1, value_contents (arg1),
return ada_value_primitive_packed_val (arg1,
value_contents (arg1).data (),
offset + bit_pos / 8,
bit_pos % 8, bit_size, type);
}
@ -8480,7 +8486,7 @@ ada_to_fixed_value_create (struct type *type0, CORE_ADDR address,
/* Our value does not live in memory; it could be a convenience
variable, for instance. Create a not_lval value using val0's
contents. */
return value_from_contents (type, value_contents (val0));
return value_from_contents (type, value_contents (val0).data ());
}
return value_from_contents_and_address (type, 0, address);
@ -8916,8 +8922,9 @@ ada_promote_array_of_integrals (struct type *type, struct value *val)
{
struct value *elt = value_cast (elt_type, value_subscript (val, lo + i));
memcpy (value_contents_writeable (res) + (i * TYPE_LENGTH (elt_type)),
value_contents_all (elt), TYPE_LENGTH (elt_type));
memcpy ((value_contents_writeable (res).data ()
+ (i * TYPE_LENGTH (elt_type))),
value_contents_all (elt).data (), TYPE_LENGTH (elt_type));
}
return res;
@ -9033,7 +9040,7 @@ ada_value_binop (struct value *arg1, struct value *arg2, enum exp_opcode op)
}
val = allocate_value (type1);
store_unsigned_integer (value_contents_raw (val),
store_unsigned_integer (value_contents_raw (val).data (),
TYPE_LENGTH (value_type (val)),
type_byte_order (type1), v);
return val;
@ -9065,7 +9072,8 @@ ada_value_equal (struct value *arg1, struct value *arg2)
representations use all bits (no padding or undefined bits)
and do not have user-defined equality. */
return (TYPE_LENGTH (arg1_type) == TYPE_LENGTH (arg2_type)
&& memcmp (value_contents (arg1), value_contents (arg2),
&& memcmp (value_contents (arg1).data (),
value_contents (arg2).data (),
TYPE_LENGTH (arg1_type)) == 0);
}
return value_equal (arg1, arg2);