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| author |   Arnd Bergmann <arnd@arndb.de> | 2017-03-28 16:11:18 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-03-28 21:42:32 -0700 |
| commit | 16b8b6de32572207abeb4dfb74ab7bd8409a5690 (patch) | |
| tree | 80b548f5995aa6149d1bc89bf4663d7c32381c24 /drivers/net/ethernet/rocker/rocker_ofdpa.c | |
| parent | net/mlx5: Avoid dereferencing uninitialized pointer (diff) | |
| download | linux-dev-16b8b6de32572207abeb4dfb74ab7bd8409a5690.tar.xz linux-dev-16b8b6de32572207abeb4dfb74ab7bd8409a5690.zip | |
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: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/rocker/rocker_ofdpa.c')
| -rw-r--r-- | drivers/net/ethernet/rocker/rocker_ofdpa.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/net/ethernet/rocker/rocker_ofdpa.c b/drivers/net/ethernet/rocker/rocker_ofdpa.c index 7cd76b6b5cb9..2ae852454780 100644 --- a/drivers/net/ethernet/rocker/rocker_ofdpa.c +++ b/drivers/net/ethernet/rocker/rocker_ofdpa.c @@ -2216,18 +2216,15 @@ static int ofdpa_port_stp_update(struct ofdpa_port *ofdpa_port, { bool want[OFDPA_CTRL_MAX] = { 0, }; bool prev_ctrls[OFDPA_CTRL_MAX]; - u8 uninitialized_var(prev_state); + u8 prev_state; int err; int i; - if (switchdev_trans_ph_prepare(trans)) { - memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls)); - prev_state = ofdpa_port->stp_state; - } - - if (ofdpa_port->stp_state == state) + prev_state = ofdpa_port->stp_state; + if (prev_state == state) return 0; + memcpy(prev_ctrls, ofdpa_port->ctrls, sizeof(prev_ctrls)); ofdpa_port->stp_state = state; switch (state) { |