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, 7 insertions, 14 deletions

diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
index 8d6f6014870f..b0c22cad9423 100644
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -58,12 +58,11 @@ static int mmc_bus_match(struct device *dev, struct device_driver *drv)
 }
 
 static int
-mmc_bus_uevent(struct device *dev, char **envp, int num_envp, char *buf,
-                int buf_size)
+mmc_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         struct mmc_card *card = dev_to_mmc_card(dev);
         const char *type;
-        int i = 0, length = 0;
+        int retval = 0;
 
         switch (card->type) {
         case MMC_TYPE_MMC:
@@ -80,20 +79,14 @@ mmc_bus_uevent(struct device *dev, char **envp, int num_envp, char *buf,
         }
 
         if (type) {
-                if (add_uevent_var(envp, num_envp, &i,
-                                buf, buf_size, &length,
-                                "MMC_TYPE=%s", type))
-                        return -ENOMEM;
+                retval = add_uevent_var(env, "MMC_TYPE=%s", type);
+                if (retval)
+                        return retval;
         }
 
-        if (add_uevent_var(envp, num_envp, &i,
-                        buf, buf_size, &length,
-                        "MMC_NAME=%s", mmc_card_name(card)))
-                return -ENOMEM;
+        retval = add_uevent_var(env, "MMC_NAME=%s", mmc_card_name(card));
 
-        envp[i] = NULL;
-
-        return 0;
+        return retval;
 }
 
 static int mmc_bus_probe(struct device *dev)