Hello Sebastian,
thank you for review, please see inline
W dniu 08.11.2013 09:02, Sebastian Andrzej Siewior pisze:
On 10/23/2013 02:25 PM, Andrzej Pietrasiewicz wrote:
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 0658908..9ccda73 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1901,30 +1916,38 @@ static int __ffs_data_got_strings(struct ffs_data *ffs,
/* Allocate everything in one chunk so there's less maintenance. */
{
- struct {
- struct usb_gadget_strings *stringtabs[lang_count + 1];
- struct usb_gadget_strings stringtab[lang_count];
- struct usb_string strings[lang_count*(needed_count+1)];
- } *d;
unsigned i = 0;
+ vla_group(d);
+ vla_item(d, struct usb_gadget_strings *, stringtabs,
+ lang_count + 1);
+ vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
+ vla_item(d, struct usb_string, strings,
+ lang_count*(needed_count+1));
- d = kmalloc(sizeof *d, GFP_KERNEL);
- if (unlikely(!d)) {
+ char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
+
+ if (unlikely(!vlabuf)) {
kfree(_data);
return -ENOMEM;
}
- stringtabs = d->stringtabs;
- t = d->stringtab;
+ /* Initialize the VLA pointers */
+ vla_ptr(vlabuf, d, stringtabs);
+ vla_ptr(vlabuf, d, stringtab);
+ vla_ptr(vlabuf, d, strings);
+
+ stringtabs = d_stringtabs;
+ t = d_stringtab;
i = lang_count;
do {
*stringtabs++ = t++;
} while (--i);
*stringtabs = NULL;
- stringtabs = d->stringtabs;
- t = d->stringtab;
- s = d->strings;
+ /* stringtabs = vlabuf = d_stringtabs for later kfree */
+ stringtabs = d_stringtabs;
+ t = d_stringtab;
+ s = d_strings;
strings = s;
}
Couldn't you use usb_gstrings_attach() instead? It should do the same
job without those macros.
Please correct me if I'm wrong but I think it is not possible to use
usb_gstrings_attach(). Basically, usb_gstrings_attach() requires
struct usb_gadget_strings **sp
on input, then it does copy_gadget_strings(sp, n_gstrings, n_strings);
and then does its job. So actually to do usb_gstrings_attach() you need
to _already_ have struct usb_gadget_strings **sp.
FunctionFS is different in that it takes data to _build_
usb_gadget_strings **stringtabs from userspace (the char *const _data).
In other words, the string descriptors are provided from userspace as
a character buffer which needs to be parsed and it is what
__ffs_data_got_strings() does.
Andrzej
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