On 01/15/15 at 01:28pm, Dan Carpenter wrote:
> On Thu, Jan 15, 2015 at 05:54:55PM +0800, Dave Young wrote:
> > > out_add_entry:
> > > - for (j = i - 1; j > 0; j--) {
> > > + for (j = i - 1; j >= 0; j--) {
> > > entry = *(map_entries + j);
> > > kobject_put(&entry->kobj);
> > > }
> >
> > see below code, as for an invalid entry with i = 0, it will be not
> > assigned to *(map_entries + i)
>
> Yes. Of course, if the first iteration fails then we want the free loop
> to be a noop and it is in my code as well. j = -1. -1 is not >= 0.
> The problem is in later iterations.
>
> >
> > ---
> > for (i = 0; i < nr_efi_runtime_map; i++) {
> > entry = add_sysfs_runtime_map_entry(efi_kobj, i);
>
> Assume that this is the second iteration and "i == 1".
>
> > if (IS_ERR(entry)) {
> > ret = PTR_ERR(entry);
> > goto out_add_entry;
>
> Assume it fails so we hit this goto. We want to free the first entry.
>
> > }
> > *(map_entries + i) = entry;
> > }
> >
> > return 0;
> > out_add_entry:
> > for (j = i - 1; j > 0; j--) {
> > entry = *(map_entries + j);
>
> In your code, "j == 1 - 1" and that's not greater than zero so we don't
> enter this loop. In my code, we go through the loop one time.
>
> By the way this code would be a lot more clear if you used arrays.
> "map_entries[j]" is more clear than "*(map_entries + j)". Even in the
> other patch, passing "&foo[i]" is more clear than "foo + i".
Oops, I got your point, thanks. Will ack the patches.
I used to use the pointer, but if you want arrays, feel free to send a patch.
Thanks
Dave
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