[patch] TTY: snyclinkmp: forever loop in tx_load_dma_buffer()

From: Dan Carpenter
Date: Tue Sep 27 2011 - 02:21:34 EST


My main concern here was the line that said:
copy_count = min_t(unsigned short,count,SCABUFSIZE);
"count" is an unsigned int here so the cast to unsigned short
truncates the upper bits. So if count is 0x10000 then copy_count is
0 and the loop never exits.

"count" comes from skb->len in hdlcdev_xmit().

The other min_t() changes are just cleanups.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
Compile tested only.

diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index c77831c..0f6b796 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -4950,7 +4950,7 @@ CheckAgain:

if ( debug_level >= DEBUG_LEVEL_DATA )
trace_block(info,info->rx_buf_list_ex[StartIndex].virt_addr,
- min_t(int, framesize,SCABUFSIZE),0);
+ min_t(unsigned int, framesize, SCABUFSIZE), 0);

if (framesize) {
if (framesize > info->max_frame_size)
@@ -5015,14 +5015,14 @@ static void tx_load_dma_buffer(SLMP_INFO *info, const char *buf, unsigned int co
SCADESC_EX *desc_ex;

if ( debug_level >= DEBUG_LEVEL_DATA )
- trace_block(info,buf, min_t(int, count,SCABUFSIZE), 1);
+ trace_block(info, buf, min_t(unsigned int, count, SCABUFSIZE), 1);

/* Copy source buffer to one or more DMA buffers, starting with
* the first transmit dma buffer.
*/
for(i=0;;)
{
- copy_count = min_t(unsigned short,count,SCABUFSIZE);
+ copy_count = min_t(unsigned int, count, SCABUFSIZE);

desc = &info->tx_buf_list[i];
desc_ex = &info->tx_buf_list_ex[i];
--
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