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| author | Marc Kleine-Budde <mkl@pengutronix.de> | 2022-08-01 22:47:16 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2022-08-09 09:05:06 +0200 |
| commit | a4cb6e62ea4d36e53fb3c0f18ea4503d7b76674f (patch) | |
| tree | e528e7be8072610945351831ee62dadecd18fd4b /drivers/net/can/usb | |
| parent | 8c21c54a53ab21842f5050fa090f26b03c0313d6 (diff) | |
| download | linux-a4cb6e62ea4d36e53fb3c0f18ea4503d7b76674f.tar.bz2 | |
can: ems_usb: fix clang's -Wunaligned-access warning
clang emits a -Wunaligned-access warning on struct __packed
ems_cpc_msg.
The reason is that the anonymous union msg (not declared as packed) is
being packed right after some non naturally aligned variables (3*8
bits + 2*32) inside a packed struct:
| struct __packed ems_cpc_msg {
| u8 type; /* type of message */
| u8 length; /* length of data within union 'msg' */
| u8 msgid; /* confirmation handle */
| __le32 ts_sec; /* timestamp in seconds */
| __le32 ts_nsec; /* timestamp in nano seconds */
| /* ^ not naturally aligned */
|
| union {
| /* ^ not declared as packed */
| u8 generic[64];
| struct cpc_can_msg can_msg;
| struct cpc_can_params can_params;
| struct cpc_confirm confirmation;
| struct cpc_overrun overrun;
| struct cpc_can_error error;
| struct cpc_can_err_counter err_counter;
| u8 can_state;
| } msg;
| };
Starting from LLVM 14, having an unpacked struct nested in a packed
struct triggers a warning. c.f. [1].
Fix the warning by marking the anonymous union as packed.
[1] https://github.com/llvm/llvm-project/issues/55520
Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface")
Link: https://lore.kernel.org/all/20220802094021.959858-1-mkl@pengutronix.de
Cc: Gerhard Uttenthaler <uttenthaler@ems-wuensche.com>
Cc: Sebastian Haas <haas@ems-wuensche.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/usb')
| -rw-r--r-- | drivers/net/can/usb/ems_usb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index d1e1a459c045..d31191686a54 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -195,7 +195,7 @@ struct __packed ems_cpc_msg { __le32 ts_sec; /* timestamp in seconds */ __le32 ts_nsec; /* timestamp in nano seconds */ - union { + union __packed { u8 generic[64]; struct cpc_can_msg can_msg; struct cpc_can_params can_params; |