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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2021-04-22 12:02:29 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-26 11:48:31 +0200 |
| commit | dcbce0b6f38476b380a0dec28e237d9398ca2bfe (patch) | |
| tree | 7a3cf88c1521d432640936eb415d896d122c964c /drivers/firmware | |
| parent | 1e986fe9ad15b8406034c504afc5ae76f0a8e852 (diff) | |
firmware: arm_scpi: Prevent the ternary sign expansion bug
[ Upstream commit d9cd78edb2e6b7e26747c0ec312be31e7ef196fe ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 c7d06a36b23a..baa7280eccb3 100644 --- a/drivers/firmware/arm_scpi.c +++ b/drivers/firmware/arm_scpi.c @@ -563,8 +563,10 @@ 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) |