Messages in this thread Patch in this message | | | From | Julia Lawall <> | Subject | [PATCH 1/3] Input: elan_i2c_smbus - cast sizeof to int for comparison | Date | Sun, 1 Jul 2018 19:32:03 +0200 |
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Comparing an int to a size, which is unsigned, causes the int to become unsigned, giving the wrong result. i2c_smbus_read_block_data can return the result of i2c_smbus_xfer, whih can return a negative error code.
A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/)
// <smpl> @@ int x; expression e,e1; identifier f; @@
*x = f(...); ... when != x = e1 when != if (x < 0 || ...) { ... return ...; } *x < sizeof(e) // </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
--- drivers/input/mouse/elan_i2c_smbus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/input/mouse/elan_i2c_smbus.c b/drivers/input/mouse/elan_i2c_smbus.c index c060d27..88e315d 100644 --- a/drivers/input/mouse/elan_i2c_smbus.c +++ b/drivers/input/mouse/elan_i2c_smbus.c @@ -387,7 +387,7 @@ static int elan_smbus_prepare_fw_update(struct i2c_client *client) len = i2c_smbus_read_block_data(client, ETP_SMBUS_IAP_PASSWORD_READ, val); - if (len < sizeof(u16)) { + if (len < (int)sizeof(u16)) { error = len < 0 ? len : -EIO; dev_err(dev, "failed to read iap password: %d\n", error);
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