Re: [SCM] master: Implement hasWatchpointTriggered in abstract, and sub-classes.

[Phil Muldoon <pmuldoon@redhat.com>]

pmuldoon@sourceware.org wrote:

This implements a function that checks the debug status register on 
whether a hardware debug data breakpoint (watchpoint) has been 
triggered. Normally this function is called after a SIGTRAP is issued 
from ptrace. On x8664 and IA32 the first four bits represent the four 
hardware breakpoint registers.  If bit  0 = 1 then the debug hardware 
data breakpoint (D0) has triggered, bit 1 for D1 and so on. I believe 
the software is responsible for clearing the bit if set, and I have not 
done this here. I'm torn whether to reset the bit if:

debugStatus & (1L << index)) != 0;

where debug status is the debug status register,  and index is the 
watchpoint to check. Should the bit be reset in hasWatchpointTriggered? 
Or in a separate function function called as a separate API?

Regards

Phil
> The branch, master has been updated
>        via  a0fc4305e0afa24959ac5cd073f65c6bb50eb8b0 (commit)
>       from  b927d6c13dcc27d155895895fcb958b4c32fb595 (commit)
>
> Those revisions listed above that are new to this repository have
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>
> - Log -----------------------------------------------------------------
> commit a0fc4305e0afa24959ac5cd073f65c6bb50eb8b0
> Author: Phil Muldoon <pmuldoon@redhat.com>
> Date:   Tue Apr 1 21:48:19 2008 +0100
>
>     Implement hasWatchpointTriggered in abstract, and sub-classes.
>     
>     2008-04-01  Phil Muldoon  <pmuldoon@redhat.com>
>     
>     	* Watchpoint.java (hasWatchpointTriggered): Define.
>     	* IA32Watchpoint.java (hasWatchpointTriggered): Implement.
>     	* X8664Watchpoint.java (hasWatchpointTriggered): Ditto.
>
> -----------------------------------------------------------------------
>
> Summary of changes:
>  frysk-core/frysk/isa/watchpoints/ChangeLog         |    6 ++++++
>  .../frysk/isa/watchpoints/IA32Watchpoint.java      |   13 ++++++++++++-
>  frysk-core/frysk/isa/watchpoints/Watchpoint.java   |   10 ++++++++++
>  .../frysk/isa/watchpoints/X8664Watchpoint.java     |   12 ++++++++++++
>  4 files changed, 40 insertions(+), 1 deletions(-)
>
> First 500 lines of diff:
> diff --git a/frysk-core/frysk/isa/watchpoints/ChangeLog b/frysk-core/frysk/isa/watchpoints/ChangeLog
> index 0e4f56f..f53652b 100644
> --- a/frysk-core/frysk/isa/watchpoints/ChangeLog
> +++ b/frysk-core/frysk/isa/watchpoints/ChangeLog
> @@ -1,3 +1,9 @@
> +2008-04-01  Phil Muldoon  <pmuldoon@redhat.com>
> +
> +	* Watchpoint.java (hasWatchpointTriggered): Define.
> +	* IA32Watchpoint.java (hasWatchpointTriggered): Implement.
> +	* X8664Watchpoint.java (hasWatchpointTriggered): Ditto.
> +
>  2008-03-28  Phil Muldoon <pmuldoon@redhat.com>
>  
>  	* Watchpoint.java: New. Initial Implementation.
> diff --git a/frysk-core/frysk/isa/watchpoints/IA32Watchpoint.java b/frysk-core/frysk/isa/watchpoints/IA32Watchpoint.java
> index 3627d03..5f97636 100644
> --- a/frysk-core/frysk/isa/watchpoints/IA32Watchpoint.java
> +++ b/frysk-core/frysk/isa/watchpoints/IA32Watchpoint.java
> @@ -197,7 +197,18 @@ class IA32Watchpoint extends Watchpoint {
>  	    task.setRegister(IA32Registers.DEBUG_CONTROL, debugControl);
>      }
>  
> -    
> +    /**
> +     * Reads the Debug Status Register and checks if 
> +     * the breakpoint specified has fired.
> +     *
> +     * @param task - task to read the debug control
> +     * register from.
> +     */
> +    public boolean hasWatchpointTriggered(Task task, int index) {
> +	long debugStatus = task.getRegister(IA32Registers.DEBUG_STATUS);	
> +	return (debugStatus & (1L << index)) != 0;
> +    }
> +
>  
>      /**
>       * Reads the Debug control register.
> diff --git a/frysk-core/frysk/isa/watchpoints/Watchpoint.java b/frysk-core/frysk/isa/watchpoints/Watchpoint.java
> index fc8c234..a0ef202 100644
> --- a/frysk-core/frysk/isa/watchpoints/Watchpoint.java
> +++ b/frysk-core/frysk/isa/watchpoints/Watchpoint.java
> @@ -94,6 +94,16 @@ public abstract class Watchpoint  {
>       */
>      public abstract long readControlRegister(Task task);
>  
> +    
> +    /**
> +     * Reads the Debug Status Register and checks if 
> +     * the breakpoint specified has fired.
> +     *
> +     * @param task - task to read the debug control
> +     * register from.
> +     */
> +    public abstract boolean hasWatchpointTriggered(Task task, int index);
> +
>      /**
>       * Returns number of watchpoints for this architecture
>       *
> diff --git a/frysk-core/frysk/isa/watchpoints/X8664Watchpoint.java b/frysk-core/frysk/isa/watchpoints/X8664Watchpoint.java
> index c581f92..1df98a5 100644
> --- a/frysk-core/frysk/isa/watchpoints/X8664Watchpoint.java
> +++ b/frysk-core/frysk/isa/watchpoints/X8664Watchpoint.java
> @@ -205,5 +205,17 @@ class X8664Watchpoint extends Watchpoint {
>  	return task.getRegister(X8664Registers.DEBUG_CONTROL);
>      }
>  
> +    /**
> +     * Reads the Debug Status Register and checks if 
> +     * the breakpoint specified has fired.
> +     *
> +     * @param task - task to read the debug control
> +     * register from.
> +     */
> +    public boolean hasWatchpointTriggered(Task task, int index) {
> +	long debugStatus = task.getRegister(X8664Registers.DEBUG_STATUS);
> +	return (debugStatus & (1L << index)) != 0;
> +    }
> +
>  
>  }
>
>
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