Hi, On Fri, Feb 03, 2023 at 05:22:40PM +0100, Takashi Iwai wrote: > On Thu, 02 Feb 2023 14:37:08 +0100, > Takashi Sakamoto wrote: > > > > Current structure includes no field to express the number of messages > > copied to user space, thus user space application needs to information > > out of the structure to parse the content of structure. > > > > This commit adds a field to express the number of messages copied to user > > space since It is more preferable to use self-contained structure. > > > > Kees Cook proposed an idea of annotation for bound of flexible arrays > > in his future improvement for flexible-length array in kernel. The > > additional field for message count is suitable to the idea as well. > > > > Reference: https://people.kernel.org/kees/bounded-flexible-arrays-in-c > > Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx> > > Wouldn't changing this break the existing application that talks with > the older ABI? Just to be sure... You may well have the concern, indeed. The structure is not exposed to user space yet, since it was added by a commit ab811cfffa9 ("ALSA: fireface: update UAPI for data of knob control"). It just exists in your (and mine) tree at present. Thanks Takashi Sakamoto
