On Mon, Mar 22, 2021 at 12:44:34PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Building with 'make W=1' shows a harmless warning for pscsi:
>
> drivers/target/target_core_pscsi.c: In function 'pscsi_complete_cmd':
> drivers/target/target_core_pscsi.c:624:33: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
> 624 | ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
> | ^
>
> Rework the coding style as suggested by gcc to avoid the warning.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/target/target_core_pscsi.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
> index 3cbc074992bc..913b092955f6 100644
> --- a/drivers/target/target_core_pscsi.c
> +++ b/drivers/target/target_core_pscsi.c
> @@ -620,8 +620,9 @@ static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
> unsigned char *buf;
>
> buf = transport_kmap_data_sg(cmd);
> - if (!buf)
> - ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
> + if (!buf) {
> + /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
> + }
But why not just delete the code?
buf = transport_kmap_data_sg(cmd);
/* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
I mean, this seems like a real warning here. We're not actually
handling the failure to allocate 'buf'. It's not marked as __must_check,
but watch the code flow:
buf = transport_kmap_data_sg(cmd);
if (!buf)
; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
if (cdb[0] == MODE_SENSE_10) {
if (!(buf[3] & 0x80))
buf[3] |= 0x80;
} else {
if (!(buf[2] & 0x80))
buf[2] |= 0x80;
}
we're about to do a NULL ptr dereference. So this should be handled
somehow.
