From: Dave Hansen <haveblue@us.ibm.com>
This patch fixes a race condition that would panic the kernel when
replenishing a buffer pool.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/net/ibmveth.c | 5 +++--
25-akpm/drivers/net/ibmveth.h | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff -puN drivers/net/ibmveth.c~ibmveth-race-fix drivers/net/ibmveth.c
--- 25/drivers/net/ibmveth.c~ibmveth-race-fix 2004-08-15 13:02:38.527999712 -0700
+++ 25-akpm/drivers/net/ibmveth.c 2004-08-15 13:02:38.532998952 -0700
@@ -214,11 +214,12 @@ static void ibmveth_replenish_buffer_poo
free_index = pool->consumer_index++ % pool->size;
index = pool->free_map[free_index];
- ibmveth_assert(index != 0xffff);
+ ibmveth_assert(index != IBM_VETH_INVALID_MAP);
ibmveth_assert(pool->skbuff[index] == NULL);
dma_addr = vio_map_single(adapter->vdev, skb->data, pool->buff_size, DMA_FROM_DEVICE);
+ pool->free_map[free_index] = IBM_VETH_INVALID_MAP;
pool->dma_addr[index] = dma_addr;
pool->skbuff[index] = skb;
@@ -233,6 +234,7 @@ static void ibmveth_replenish_buffer_poo
lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address, desc.desc);
if(lpar_rc != H_Success) {
+ pool->free_map[free_index] = IBM_VETH_INVALID_MAP;
pool->skbuff[index] = NULL;
pool->consumer_index--;
vio_unmap_single(adapter->vdev, pool->dma_addr[index], pool->buff_size, DMA_FROM_DEVICE);
@@ -240,7 +242,6 @@ static void ibmveth_replenish_buffer_poo
adapter->replenish_add_buff_failure++;
break;
} else {
- pool->free_map[free_index] = 0xffff;
buffers_added++;
adapter->replenish_add_buff_success++;
}
diff -puN drivers/net/ibmveth.h~ibmveth-race-fix drivers/net/ibmveth.h
--- 25/drivers/net/ibmveth.h~ibmveth-race-fix 2004-08-15 13:02:38.528999560 -0700
+++ 25-akpm/drivers/net/ibmveth.h 2004-08-15 13:02:38.540997736 -0700
@@ -77,6 +77,8 @@
#define IbmVethPool1DftCnt 256
#define IbmVethPool2DftCnt 256
+#define IBM_VETH_INVALID_MAP ((u16)0xffff)
+
struct ibmveth_buff_pool {
u32 size;
u32 index;
_