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authorcinap_lenrek <cinap_lenrek@felloff.net>2018-01-08 00:23:26 +0100
committercinap_lenrek <cinap_lenrek@felloff.net>2018-01-08 00:23:26 +0100
commitacb206859deafd32c5ef1901560dc13be2c0d280 (patch)
tree58b5478b622d702f171af73a6d616a8c951e17d5 /sys/src/9
parent069230cd621ae5b3b9ab6e1a31eb6250fc86e30b (diff)
ether8169: deal with kernel memory exhaution
when kernel memory is exhausted, rtl8169replenish() can fail to plant more receive descriptors and rtl8169receive() would run over the receive tail and crash on the nil ctlr->rb[x]. rtl8169receive() is called on "Receive Descriptor Unavailable" and "Packet Underrun" so we will try to replenish descriptors in the beginning first in case memory was exhausted and memory is available again and make sure not to run over the tail.
Diffstat (limited to 'sys/src/9')
-rw-r--r--sys/src/9/pc/ether8169.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/sys/src/9/pc/ether8169.c b/sys/src/9/pc/ether8169.c
index 02f39c5f3..734608ab9 100644
--- a/sys/src/9/pc/ether8169.c
+++ b/sys/src/9/pc/ether8169.c
@@ -919,8 +919,10 @@ rtl8169receive(Ether* edev)
int x;
ctlr = edev->ctlr;
- x = ctlr->rdh;
- for(;;){
+ if(ctlr->nrq < ctlr->nrd/2)
+ rtl8169replenish(ctlr);
+
+ for(x = ctlr->rdh; x != ctlr->rdt;){
d = &ctlr->rd[x];
if((control = d->control) & Own)
break;