diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2021-04-22 12:02:29 +0300 |
|---|---|---|
| committer | Sudeep Holla <sudeep.holla@arm.com> | 2021-04-27 11:55:57 +0100 |
| commit | d9cd78edb2e6b7e26747c0ec312be31e7ef196fe (patch) | |
| tree | 6d9e447831f1d4fc2a1cfa68be50c7094517dd18 /drivers/firmware | |
| parent | d4f9dddd21f39395c62ea12d3d91239637d4805f (diff) | |
firmware: arm_scpi: Prevent the ternary sign expansion bug
How the type promotion works in ternary expressions is a bit tricky.
The problem is that scpi_clk_get_val() returns longs, "ret" is a int
which holds a negative error code, and le32_to_cpu() is an unsigned int.
We want the negative error code to be cast to a negative long. But
because le32_to_cpu() is an u32 then "ret" is type promoted to u32 and
becomes a high positive and then it is promoted to long and it is still
a high positive value.
Fix this by getting rid of the ternary.
Link: https://lore.kernel.org/r/YIE7pdqV/h10tEAK@mwanda
Fixes: 8cb7cf56c9fe ("firmware: add support for ARM System Control and Power Interface(SCPI) protocol")
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[sudeep.holla: changed to return 0 as clock rate on error]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/arm_scpi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c index d0dee37ad522..4ceba5ef7895 100644 --- a/drivers/firmware/arm_scpi.c +++ b/drivers/firmware/arm_scpi.c @@ -552,8 +552,10 @@ static unsigned long scpi_clk_get_val(u16 clk_id) ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id, sizeof(le_clk_id), &rate, sizeof(rate)); + if (ret) + return 0; - return ret ? ret : le32_to_cpu(rate); + return le32_to_cpu(rate); } static int scpi_clk_set_val(u16 clk_id, unsigned long rate) |