Commit 16b8b6de authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller

rocker: fix Wmaybe-uninitialized false-positive

gcc-7 reports a warning that earlier versions did not have:

drivers/net/ethernet/rocker/rocker_ofdpa.c: In function 'ofdpa_port_stp_update':
arch/x86/include/asm/string_32.h:79:22: error: '*((void *)&prev_ctrls+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   *((short *)to + 2) = *((short *)from + 2);
   ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/rocker/rocker_ofdpa.c:2218:7: note: '*((void *)&prev_ctrls+4)' was declared here

This is clearly a variation of the warning about 'prev_state' that
was shut up using uninitialized_var().

We can slightly simplify the code and get rid of the warning by unconditionally
saving the prev_state and prev_ctrls variables. The inlined memcpy is not
particularly expensive here, as it just has to read five bytes from one or
two cache lines.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e497ec68
...@@ -2216,18 +2216,15 @@ static int ofdpa_port_stp_update(struct ofdpa_port *ofdpa_port, ...@@ -2216,18 +2216,15 @@ static int ofdpa_port_stp_update(struct ofdpa_port *ofdpa_port,
{ {
bool want[OFDPA_CTRL_MAX] = { 0, }; bool want[OFDPA_CTRL_MAX] = { 0, };
bool prev_ctrls[OFDPA_CTRL_MAX]; bool prev_ctrls[OFDPA_CTRL_MAX];
u8 uninitialized_var(prev_state); u8 prev_state;
int err; int err;
int i; int i;
if (switchdev_trans_ph_prepare(trans)) {
memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls));
prev_state = ofdpa_port->stp_state; prev_state = ofdpa_port->stp_state;
} if (prev_state == state)
if (ofdpa_port->stp_state == state)
return 0; return 0;
memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls));
ofdpa_port->stp_state = state; ofdpa_port->stp_state = state;
switch (state) { switch (state) {
......
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