[U-Boot-Users] PATCH fix 440gx_enet.c driver was: WARNING: in 440gx_enet.c

Travis B. Sawyer tsawyer+u-boot at sandburst.com
Fri Jun 10 15:03:39 CEST 2005

Roberts, John wrote:
> U-Boot 1.1.2
> In function: int ppc_440x_eth_initialize (bd_t * bis)
> This function malloc's a data structures
> 		/* Allocate our private use data */
> 		hw = (EMAC_440GX_HW_PST) malloc (sizeof (EMAC_440GX_HW_ST));
> Later in function: static int ppc_440x_eth_init (struct eth_device *dev,
> bd_t * bis)
> 	/* Free "old" buffers */
> 	if (hw_p->alloc_tx_buf)
> 		free (hw_p->alloc_tx_buf);
> 	if (hw_p->alloc_rx_buf)
> 		free (hw_p->alloc_rx_buf);
> The first time through, the code assumes hw_p->alloc_tx_buf and
> hw_p->alloc_rx_buf will be zero. A malloc doesn't guarantee that and the
> variables are never initialized to zero. If the malloc'd memory is all "F"s
> you end up with : free(0xFFFFFFFF); Or it may be any random non-zero value
> you try to free.
> I added a memset after the malloc to init the struct to zero. I suppose
> replacing the malloc with calloc will do the trick as well.

(file) 405gp_enet.c 	 1.11 	 11 months 	 stroese 	 Fix bug in 405 
ethernet driver; allocated data not cleared!

Hmmm... Looks like I let that slip by when Stefan updated the 405
ethernet driver and I didn't update the 440 version.

* Patch by Travis Sawyer, 10 June 2005:
   Initialize allocated dev and private hw structures
   after their respective allocation in 440gx_enet.c

Patch is attached...


-------------- next part --------------
A non-text attachment was scrubbed...
Name: 440gx_enet_malloc.patch
Type: text/x-patch
Size: 685 bytes
Desc: not available
Url : http://lists.denx.de/pipermail/u-boot/attachments/20050610/c6f63e86/attachment.bin 

More information about the U-Boot mailing list