[ppc-linux-nat]: set access flag for h/w watchpoint even if it is only read or write

[Wu Zhou <woodzltc@cn.ibm.com>]

Hello all,

I found a bug in the current ppc-linux h/w watchpoint implementation:  
when we set read watchpoint to some expression, if there are any write 
operation to it before a read operation is hit, watchpoint_check will see 
that its value is changed. So user won't see the watchpoint is hit.

I make one change to the SET_DEBUGREG operation: even if it is only 
read or write watchpoint, we still set access flag.  Then, no matter 
what operation is on the watched address, a SIGTRAP will be triggered. 
The gdb code itself can determine if it is a write operation or read 
operation.  If it is write, watchpoint_check routine can update the 
bs->value to the latest.  

Here is the patch.  Thanks for reviewing.

2006-06-09  Wu Zhou  <woodzltc@cn.ibm.com>

	* ppc-linux-nat.c (ppc_linux_insert_watchpoint): Set access flag for
	all hardware watchpoint.

--- ppc-linux-nat.c.orig	2006-06-09 14:53:35.000000000 +0800
+++ ppc-linux-nat.c	2006-06-09 15:04:12.000000000 +0800
@@ -821,22 +821,7 @@ ppc_linux_insert_watchpoint (CORE_ADDR a
   long dabr_value;
   ptid_t ptid = inferior_ptid;
 
-  dabr_value = addr & ~7;
-  switch (rw)
-    {
-    case hw_read:
-      /* Set read and translate bits.  */
-      dabr_value |= 5;
-      break;
-    case hw_write:
-      /* Set write and translate bits.  */
-      dabr_value |= 6;
-      break;
-    case hw_access:
-      /* Set read, write and translate bits.  */
-      dabr_value |= 7;
-      break;
-    }
+  dabr_value = addr | 7;
 
   tid = TIDGET (ptid);
   if (tid == 0)


:ADDPATCH ppc:

Regards
- Wu Zhou