Re: Problem with __check_and_rekey

["David S. Miller" <davem@xxxxxxxxxx>]

On Tue, 12 Aug 2003 22:55:27 +0900 (JST)
YOSHIFUJI Hideaki / _$B5HF#1QL@ <yoshfuji@xxxxxxxxxxxxxx> wrote:

> > +               local_bh_disable();
> >                 tp->write_seq = secure_tcp_sequence_number(sk->saddr, 
> > sk->daddr,
> >                                                            sk->sport, 
> > usin->sin_port);
> > +               local_bh_enable();
> 
> You must forgot braces.
> But anyway, I can't find these lines in linux-2.4.21 (or even in 2.6.x).
> Are you sure you're working on the vanilla kernel?

It doesn't matter, a proper fix was put into drivers/char/random.c
already.

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#                  ChangeSet    1.1019.3.9 -> 1.1019.3.10
#       drivers/char/random.c   1.17    -> 1.18   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/07/28      olof@xxxxxxxxxxxxxx     1.1019.3.10
# [RANDOM]: Fix SMP deadlock in __check_and_rekey().
# --------------------------------------------
#
diff -Nru a/drivers/char/random.c b/drivers/char/random.c
--- a/drivers/char/random.c     Tue Aug 12 06:56:52 2003
+++ b/drivers/char/random.c     Tue Aug 12 06:56:52 2003
@@ -251,6 +251,8 @@
 #include <linux/random.h>
 #include <linux/poll.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
 
 #include <asm/processor.h>
 #include <asm/uaccess.h>
@@ -2069,7 +2071,7 @@
 static struct keydata *__check_and_rekey(time_t time)
 {
        struct keydata *keyptr;
-       spin_lock(&ip_lock);
+       spin_lock_bh(&ip_lock);
        keyptr = &ip_keydata[ip_cnt&1];
        if (!keyptr->rekey_time || (time - keyptr->rekey_time) > 
REKEY_INTERVAL) {
                keyptr = &ip_keydata[1^(ip_cnt&1)];
@@ -2079,7 +2081,7 @@
                mb();
                ip_cnt++;
        }
-       spin_unlock(&ip_lock);
+       spin_unlock_bh(&ip_lock);
        return keyptr;
 }