Johannes Schindelin <Johannes.Schindelin@xxxxxx> writes:
>> > [XSI][Option Start]
>> > ino_t d_ino File serial number.
>> > [Option End]
>> > char d_name[] Filename string of entry.
>> >
>> > You will notice that not even `d_type` is guaranteed.
>>
>> I am reasonably sure that the code (without Elijah's patches anyway)
>> takes the possibility of missing d_type into account already.
>>
>> Doesn't the above mean d_name[] has to be an in-place array of some
>> size (i.e. even a flex-array is OK)? It does not look to me that it
>> allows for it to be a pointer pointing at elsewhere (possibly on
>> heap), which may be asking for trouble.
>
> You are right, of course.
>
> ...
>
> Is this compliant with POSIX? I guess not. Does it work? Yes, it does.
I actually would not throw it into "it works" category. The obvious
implication is that a program like this:
static struct dirent *fabricate(const char *name)
{
/* over-allocate as we do not know how long the d_name[] is */
struct dirent *ent = calloc(1, sizeof(*ent) + strlen(name) + 1);
strcpy(ent->d_name, name);
return ent;
}
static void show_name(const struct dirent *ent)
{
printf("%s\n", ent->d_name);
}
int main(int ac, char **av)
{
struct dirent *mine = fabricate("mine");
show_name(mine);
free(mine);
return 0;
}
would be broken if you do not have d_name as an array.
I would not be surprised if the segfaults you saw with Elijah's
series all were caused by your d_name not being an array, and if
that is the case, I'd rather see it fixed on your end than fixes
withdrawn.
Thanks.
