i2c: Check for address validity on client registration
Do basic address validity checks when a client is being registered. We
already had checks in place for devices which are being detected, but
not for devices which are simply instantiated.
This is a very basic check. We don't want to do strict checking here
because some devices are known to infringe the I2C address constraints
(e.g. IR receivers at 7-bit address 0x7a while this value is
supposedly reserved for 10-bit addresses.) So we assume the caller
knows what it is doing.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f744f73..96f0133 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -371,6 +371,22 @@
EXPORT_SYMBOL(i2c_verify_client);
+/* This is a permissive address validity check, I2C address map constraints
+ * are purposedly not enforced, except for the general call address. */
+static int i2c_check_client_addr_validity(const struct i2c_client *client)
+{
+ if (client->flags & I2C_CLIENT_TEN) {
+ /* 10-bit address, all values are valid */
+ if (client->addr > 0x3ff)
+ return -EINVAL;
+ } else {
+ /* 7-bit address, reject the general call address */
+ if (client->addr == 0x00 || client->addr > 0x7f)
+ return -EINVAL;
+ }
+ return 0;
+}
+
/**
* i2c_new_device - instantiate an i2c device
* @adap: the adapter managing the device
@@ -410,6 +426,14 @@
strlcpy(client->name, info->type, sizeof(client->name));
+ /* Check for address validity */
+ status = i2c_check_client_addr_validity(client);
+ if (status) {
+ dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
+ client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
+ goto out_err_silent;
+ }
+
/* Check for address business */
status = i2c_check_addr(adap, client->addr);
if (status)
@@ -436,6 +460,7 @@
out_err:
dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
"(%d)\n", client->name, client->addr, status);
+out_err_silent:
kfree(client);
return NULL;
}
@@ -561,15 +586,9 @@
return -EINVAL;
}
- if (info.addr < 0x03 || info.addr > 0x77) {
- dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device",
- info.addr);
- return -EINVAL;
- }
-
client = i2c_new_device(adap, &info);
if (!client)
- return -EEXIST;
+ return -EINVAL;
/* Keep track of the added device */
i2c_lock_adapter(adap);