[U-Boot] [PATCH] net: Protect net_state from reentrant net_loop()

Global variable "net_state" is used in net_loop() state-machine. But it happens that some times the net_loop() can be called multiple times in the same call stack. For example when the netconsole is enabled and we print the message while some other net protocol is in action. Netconsole will overwrite the "net_state" and that will break the logic for earlier started protocol.
To protect the state save and restore "net_state" variable each time when we enter and exit net_loop().
Signed-off-by: Leonid Iziumtsev leonid.iziumtsev@se.atlascopco.com --- net/net.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/net.c b/net/net.c index c3adba2..cb34c3b 100644 --- a/net/net.c +++ b/net/net.c @@ -417,6 +417,7 @@ void net_init(void) int net_loop(enum proto_t protocol) { int ret = -EINVAL; + enum net_loop_state prev_net_state = net_state;
net_restarted = 0; net_dev_exists = 0; @@ -454,6 +455,7 @@ restart: case 1: /* network not configured */ eth_halt(); + net_set_state(prev_net_state); return -ENODEV;
case 2: @@ -674,6 +676,7 @@ done: net_set_udp_handler(NULL); net_set_icmp_handler(NULL); #endif + net_set_state(prev_net_state); return ret; }

On Tue, May 8, 2018 at 8:55 AM, Leonid Iziumtsev leonid.iziumtsev@gmail.com wrote:
Global variable "net_state" is used in net_loop() state-machine. But it happens that some times the net_loop() can be called multiple times in the same call stack. For example when the netconsole is enabled and we print the message while some other net protocol is in action. Netconsole will overwrite the "net_state" and that will break the logic for earlier started protocol.
To protect the state save and restore "net_state" variable each time when we enter and exit net_loop().
Signed-off-by: Leonid Iziumtsev leonid.iziumtsev@se.atlascopco.com
Acked-by: Joe Hershberger joe.hershberger@ni.com

Hi Leonid,
https://patchwork.ozlabs.org/patch/910202/ was applied to http://git.denx.de/?p=u-boot/u-boot-net.git
Thanks! -Joe
participants (2)
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Joe Hershberger
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Leonid Iziumtsev