On Wed, Oct 25, 2023 at 11:27:06AM +0300, Calvince Otieno wrote: > Declaring zero-length arrays is allowed in GNU C as an extension. > Although the size of a zero-length array is zero, an array member of > this kind may increase the size of the enclosing type as a result of > tail padding. The offset of a zero-length array member from the beginning > of the enclosing structure is the same as the offset of an array with one > or more elements of the same type. The alignment of a zero-length array is > the same as the alignment of its elements. > > Declaring zero-length arrays in other contexts, including as interior > members of structure objects or as non-member objects, is discouraged. > Accessing elements of zero-length arrays declared in such contexts is > undefined and may be diagnosed. > > There are some instances of code in which the sizeof operator is being > incorrectly/erroneously applied to zero-length arrays and the result > is zero. Such instances may be hiding some bugs. > > This issue was found with the help of Coccinelle. > > [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > > Signed-off-by: Calvince Otieno <calvncce@xxxxxxxxx> > --- > drivers/staging/wlan-ng/p80211metastruct.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/staging/wlan-ng/p80211metastruct.h b/drivers/staging/wlan-ng/p80211metastruct.h > index a52217c9b953..c8b73c867391 100644 > --- a/drivers/staging/wlan-ng/p80211metastruct.h > +++ b/drivers/staging/wlan-ng/p80211metastruct.h > @@ -71,7 +71,6 @@ struct p80211msg_dot11req_scan_results { > struct p80211item_uint32 signal; > struct p80211item_uint32 noise; > struct p80211item_pstr6 bssid; > - u8 pad_3C[1]; ^ This is not a zero. This is a one. It's put there very deliberately to "pad" the struct. regards, dan carpenter >
