[RFA] PR gdb/17210 - fix possible memory leak in read_memory_robust

[Tom Tromey]

>>>>> "Yao" == Yao Qi <qiyaoltc@gmail.com> writes:

Yao> On Thu, Jun 9, 2016 at 5:33 PM, Tom Tromey <tom@tromey.com> wrote:
>> 
>> VEC(memory_read_result_s) *
>> @@ -1810,6 +1810,8 @@ read_memory_robust (struct target_ops *ops,
>> {
>> VEC(memory_read_result_s) *result = 0;
>> int unit_size = gdbarch_addressable_memory_unit_size (target_gdbarch ());
>> +  struct cleanup *cleanup = make_cleanup (free_memory_read_result_vector,
>> +                                         &result);
>> 

Yao> result is a local variable on stack, so its address is meaningless when the
Yao> exception is throw, because the stack has already been destroyed.

Yao> Probably, we can register cleanup for result once it becomes to non-NULL,
Yao> and changes in free_memory_read_result_vector are not needed.

I don't think that will work, because resizing the vector may cause the
value to change.  Though one option would be to discard the cleanup and
recreate it after each push.

Tom