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authorSam Jansen <sjansen@google.com>2007-11-29 23:07:57 +1100
committerGreg Kroah-Hartman <gregkh@suse.de>2007-12-14 09:51:04 -0800
commit470678d9f4e37380e89999b5a4f223985cf186e1 (patch)
tree9d8139594ae5dfaeebf8d201aa9516a5181293de
parentc996090b7a28d89cf1f2365688dad715b2ae7bd6 (diff)
TCP: Problem bug with sysctl_tcp_congestion_control function
[TCP]: Problem bug with sysctl_tcp_congestion_control function [ Upstream commit: 5487796f0c9475586277a0a7a91211ce5746fa6a ] sysctl_tcp_congestion_control seems to have a bug that prevents it from actually calling the tcp_set_default_congestion_control function. This is not so apparent because it does not return an error and generally the /proc interface is used to configure the default TCP congestion control algorithm. This is present in 2.6.18 onwards and probably earlier, though I have not inspected 2.6.15--2.6.17. sysctl_tcp_congestion_control calls sysctl_string and expects a successful return code of 0. In such a case it actually sets the congestion control algorithm with tcp_set_default_congestion_control. Otherwise, it returns the value returned by sysctl_string. This was correct in 2.6.14, as sysctl_string returned 0 on success. However, sysctl_string was updated to return 1 on success around about 2.6.15 and sysctl_tcp_congestion_control was not updated. Even though sysctl_tcp_congestion_control returns 1, do_sysctl_strategy converts this return code to '0', so the caller never notices the error. Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--net/ipv4/sysctl_net_ipv4.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 53ef0f4bbdaa..6ea13067253d 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -121,7 +121,7 @@ static int sysctl_tcp_congestion_control(ctl_table *table, int __user *name,
tcp_get_default_congestion_control(val);
ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen);
- if (ret == 0 && newval && newlen)
+ if (ret == 1 && newval && newlen)
ret = tcp_set_default_congestion_control(val);
return ret;
}