Re: [PATCH v2 net-next 0/7] net: speedup netns create/delete time

[Eric Dumazet]

On Wed, 2017-12-13 at 13:43 -0800, Dmitry Torokhov wrote:
> Hi Eric,
> 
> On Thu, Oct 19, 2017 at 7:11 AM, Eric Dumazet <eduma...@google.com> wrote:
> > 
> > On Thu, Oct 19, 2017 at 4:48 AM, Tariq Toukan <tar...@mellanox.com> wrote:
> > > 
> > > Hi Eric,
> > > 
> > > I just wanted to check if this is solved already, as I don't want to keep 
> > > an
> > > unnecessary revert patch in our internal branches.
> > > According to my check bug still exists.
> > > 
> > 
> > I will handle this today, thanks for the reminder.
> 
> Did you have a chance to do this? It looks like the original change
> landed on mainline and causes modules to be autoloaded on KOBJ_UNBIND
> again.
> 
> Thanks!

I sent the following to Tariq, and he tested it successfully.

I will submit this formally.

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 
c3e84edc47c965d40199b652ba78876cdaa9c70c..0795482b15d5a8f1b65b570a071aa1419cb923d8
 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -346,19 +346,25 @@ static int kobject_uevent_net_broadcast(struct kobject 
*kobj,
 static void zap_modalias_env(struct kobj_uevent_env *env)
 {
        static const char modalias_prefix[] = "MODALIAS=";
+       size_t offset = 0, len;
        int i;
 
        for (i = 0; i < env->envp_idx;) {
+               len = strlen(env->envp[i]) + 1;
                if (strncmp(env->envp[i], modalias_prefix,
                            sizeof(modalias_prefix) - 1)) {
                        i++;
+                       offset += len;
                        continue;
                }
 
-               if (i != env->envp_idx - 1)
+               env->buflen -= len;
+               if (i != env->envp_idx - 1) {
+                       memmove(env->envp[i], env->envp[i + 1],
+                               env->buflen - offset);
                        memmove(&env->envp[i], &env->envp[i + 1],
                                sizeof(env->envp[i]) * env->envp_idx - 1);
-
+               }
                env->envp_idx--;
        }
 }