[PATCH 2.6] ibmveth bug fixes 2/4

[PATCH 2.6] ibmveth bug fixes 2/4

[Santiago Leon]

[-- Attachment #1: Type: text/plain, Size: 244 bytes --]

Andrew,

This patch fixes a race condition that would panic the kernel when 
replenishing a buffer pool.  Please apply.

Signed-off-by: Santiago Leon <santil@us.ibm.com>

-- 
Santiago A. Leon
Power Linux Development
IBM Linux Technology Center

[-- Attachment #2: ibmveth_race.patch --]
[-- Type: text/plain, Size: 946 bytes --]

===== drivers/net/ibmveth.c 1.14 vs edited =====
--- 1.14/drivers/net/ibmveth.c	Tue Aug 10 11:56:29 2004
+++ edited/drivers/net/ibmveth.c	Tue Aug 10 11:57:09 2004
@@ -219,6 +219,7 @@
 
 		dma_addr = vio_map_single(adapter->vdev, skb->data, pool->buff_size, DMA_FROM_DEVICE);
 
+               pool->free_map[free_index] = 0xffff;
 		pool->dma_addr[index] = dma_addr;
 		pool->skbuff[index] = skb;
 
@@ -233,6 +234,7 @@
 		lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address, desc.desc);
 		    
 		if(lpar_rc != H_Success) {
+                       pool->free_map[free_index] = index;
 			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 @@
 			adapter->replenish_add_buff_failure++;
 			break;
 		} else {
-			pool->free_map[free_index] = 0xffff;
 			buffers_added++;
 			adapter->replenish_add_buff_success++;
 		}

Re: [PATCH 2.6] ibmveth bug fixes 2/4

[Dave Hansen]

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On Tue, 2004-08-10 at 11:06, Santiago Leon wrote:
> This patch fixes a race condition that would panic the kernel when 
> replenishing a buffer pool.  Please apply.

How about something like this that doesn't add more magic numbers?

I'm not so sure about the type, though.  Is that (u16) cast OK?

-- Dave

[-- Attachment #2: ibmveth-invalid_map.patch --]
[-- Type: text/x-patch, Size: 1602 bytes --]

--- veth/drivers/net/ibmveth.h.orig	2004-08-10 11:34:05.000000000 -0700
+++ veth/drivers/net/ibmveth.h	2004-08-10 11:35:01.000000000 -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;
--- veth/drivers/net/ibmveth.c.orig	2004-08-10 11:35:17.000000000 -0700
+++ veth/drivers/net/ibmveth.c	2004-08-10 11:37:22.000000000 -0700
@@ -213,11 +213,12 @@ 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;
 
@@ -232,6 +233,7 @@ 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);
@@ -239,7 +241,6 @@ 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++;
 		}

Re: [PATCH 2.6] ibmveth bug fixes 2/4

[Santiago Leon]

> How about something like this that doesn't add more magic numbers?
> 
> I'm not so sure about the type, though.  Is that (u16) cast OK?

Yep... Thanks Dave... no magic numbers is good... and the (u16) cast is 
ok...

Andrew... please apply Dave's patch...

-- 
Santiago A. Leon
Power Linux Development
IBM Linux Technology Center