On Tue, Aug 29, 2017 at 1:53 AM, David Ahern <dsah...@gmail.com> wrote:
> This reverts commit aa8db499ea67cff1f5f049033810ffede2fe5ae4.
>
> Early demux structs can not be made const. Doing so results in:
> [ 84.967355] BUG: unable to handle kernel paging request at ffffffff81684b10
> [ 84.969272] IP: proc_configure_early_demux+0x1e/0x3d
> [ 84.970544] PGD 1a0a067
> [ 84.970546] P4D 1a0a067
> [ 84.971212] PUD 1a0b063
> [ 84.971733] PMD 80000000016001e1
>
> [ 84.972669] Oops: 0003 [#1] SMP
> [ 84.973065] Modules linked in: ip6table_filter ip6_tables veth vrf
> [ 84.973833] CPU: 0 PID: 955 Comm: sysctl Not tainted 4.13.0-rc6+ #22
> [ 84.974612] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.7.5-20140531_083030-gandalf 04/01/2014
> [ 84.975855] task: ffff88003854ce00 task.stack: ffffc900005a4000
> [ 84.976580] RIP: 0010:proc_configure_early_demux+0x1e/0x3d
> [ 84.977253] RSP: 0018:ffffc900005a7dd0 EFLAGS: 00010246
> [ 84.977891] RAX: ffffffff81684b10 RBX: 0000000000000001 RCX:
> 0000000000000000
> [ 84.978759] RDX: 0000000000000000 RSI: 0000000000000006 RDI:
> 0000000000000000
> [ 84.979628] RBP: ffffc900005a7dd0 R08: 0000000000000000 R09:
> 0000000000000000
> [ 84.980501] R10: 0000000000000001 R11: 0000000000000008 R12:
> 0000000000000001
> [ 84.981373] R13: ffffffffffffffea R14: ffffffff81a9b4c0 R15:
> 0000000000000002
> [ 84.982249] FS: 00007feb237b7700(0000) GS:ffff88003fc00000(0000)
> knlGS:0000000000000000
> [ 84.983231] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 84.983941] CR2: ffffffff81684b10 CR3: 0000000038492000 CR4:
> 00000000000406f0
> [ 84.984817] Call Trace:
> [ 84.985133] proc_tcp_early_demux+0x29/0x30
>
> I think this is the second time such a patch has been reverted.
>
> Cc: Bhumika Goyal <bhumi...@gmail.com>
> Signed-off-by: David Ahern <dsah...@gmail.com>
> ---
> Bhumika: How are you testing these constify changes? In this case a simple
> sysctl -w net.ipv4.tcp_early_demux=1 would have shown the problem
>
I am compile testing them. In this case I did: make
net/ipv4/af_inet.o and it compiled. Is this error because of
typecasting net_protocol inside inet_add_protocol function?
Thanks,
Bhumika
> net/ipv4/af_inet.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 19aee073ba29..d678820e4306 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -1596,7 +1596,7 @@ static const struct net_protocol igmp_protocol = {
> };
> #endif
>
> -static const struct net_protocol tcp_protocol = {
> +static struct net_protocol tcp_protocol = {
> .early_demux = tcp_v4_early_demux,
> .early_demux_handler = tcp_v4_early_demux,
> .handler = tcp_v4_rcv,
> @@ -1606,7 +1606,7 @@ static const struct net_protocol tcp_protocol = {
> .icmp_strict_tag_validation = 1,
> };
>
> -static const struct net_protocol udp_protocol = {
> +static struct net_protocol udp_protocol = {
> .early_demux = udp_v4_early_demux,
> .early_demux_handler = udp_v4_early_demux,
> .handler = udp_rcv,
> --
> 2.1.4
>
