| Message ID | 20200708122248.52771-3-cristian.marussi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] firmware: arm_scmi: Remove zero-length array in SCMI Notifications | expand |
On Wed, Jul 8, 2020 at 2:24 PM Cristian Marussi <cristian.marussi@arm.com> wrote: > > Drop size_t in favour of fixed size u32 for consistency and shuffle > around fields definitions to minimize implicit padding. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> As you still have implicit padding at the end, I'd either make that explicit now, or leave the __packed attribute. The payld_sz is not actually force to be misaligned with the reordered layout, which is what's most important. Arnd
On Wed, Jul 08, 2020 at 10:38:08PM +0200, Arnd Bergmann wrote: > On Wed, Jul 8, 2020 at 2:24 PM Cristian Marussi > <cristian.marussi@arm.com> wrote: > > > > Drop size_t in favour of fixed size u32 for consistency and shuffle > > around fields definitions to minimize implicit padding. > > > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > > As you still have implicit padding at the end, I'd either make > that explicit now, or leave the __packed attribute. Do you mean expliciting that with a comment, right ? being the last member 'payld' a flexible array must be the last in order to even compile. I'm a bit confused anyway on how the trailing padding works on a struct like this which ends with a flexible array definition, so I was expecting that the trailing pads would have made no difference, given that it's used to basically give some know layout to a blob of data via casting... Thanks Cristian > > The payld_sz is not actually force to be misaligned with the > reordered layout, which is what's most important. > > Arnd
diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c index 752415367305..f441da28d91f 100644 --- a/drivers/firmware/arm_scmi/notify.c +++ b/drivers/firmware/arm_scmi/notify.c @@ -254,10 +254,10 @@ struct events_queue { * queueing it on the related &struct events_queue. */ struct scmi_event_header { - u64 timestamp; - u8 evt_id; - size_t payld_sz; - u8 payld[]; + u64 timestamp; + u32 payld_sz; + u8 evt_id; + u8 payld[]; }; struct scmi_registered_event;
Drop size_t in favour of fixed size u32 for consistency and shuffle around fields definitions to minimize implicit padding. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/notify.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)