Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 64620d668742..5b4d462117cf 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -319,16 +319,18 @@ static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 	return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 }
 
-static int acpi_device_uevent(struct device *dev, char **envp, int num_envp,
-			      char *buffer, int buffer_size)
+static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	int len;
 
-	strcpy(buffer, "MODALIAS=");
-	if (create_modalias(acpi_dev, buffer + 9, buffer_size - 9) > 0) {
-		envp[0] = buffer;
-		envp[1] = NULL;
-	}
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
+			      sizeof(env->buf) - env->buflen);
+	if (len >= (sizeof(env->buf) - env->buflen))
+		return -ENOMEM;
+	env->buflen += len;
 	return 0;
 }