On Mon, May 25, 2009 at 06:46:50AM +0530, K.Prasad wrote:
> Modify process handling code to recognise hardware debug registers during copy
> and flush operations. Introduce a new TIF_DEBUG task flag to indicate a
> process's use of debug register. Load the debug register values into a
> new CPU during initialisation.
[snip]
> Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c
> ===================================================================
> --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/process.c
> +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/process.c
> @@ -50,6 +50,7 @@
> #include <asm/syscalls.h>
> #ifdef CONFIG_PPC64
> #include <asm/firmware.h>
> +#include <asm/hw_breakpoint.h>
> #endif
> #include <linux/kprobes.h>
> #include <linux/kdebug.h>
> @@ -254,8 +255,10 @@ void do_dabr(struct pt_regs *regs, unsig
> 11, SIGSEGV) == NOTIFY_STOP)
> return;
>
> +#ifndef CONFIG_PPC64
> if (debugger_dabr_match(regs))
> return;
> +#endif
>
> /* Clear the DAC and struct entries. One shot trigger */
> #if defined(CONFIG_BOOKE)
> @@ -372,8 +375,13 @@ struct task_struct *__switch_to(struct t
>
> #endif /* CONFIG_SMP */
>
> +#ifdef CONFIG_PPC64
> + if (unlikely(test_tsk_thread_flag(new, TIF_DEBUG)))
> + arch_install_thread_hw_breakpoint(new);
> +#else
> if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
> set_dabr(new->thread.dabr);
> +#endif /* CONFIG_PPC64 */
>
> #if defined(CONFIG_BOOKE)
> /* If new thread DAC (HW breakpoint) is the same then leave it */
> @@ -550,6 +558,10 @@ void show_regs(struct pt_regs * regs)
> void exit_thread(void)
> {
> discard_lazy_cpu_state();
> +#ifdef CONFIG_PPC64
> + if (unlikely(test_tsk_thread_flag(current, TIF_DEBUG)))
> + flush_thread_hw_breakpoint(current);
> +#endif /* CONFIG_PPC64 */
> }
>
> void flush_thread(void)
> @@ -605,6 +617,9 @@ int copy_thread(unsigned long clone_flag
> struct pt_regs *childregs, *kregs;
> extern void ret_from_fork(void);
> unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
> +#ifdef CONFIG_PPC64
> + struct task_struct *tsk = current;
I don't see any point to adding this variable, just reference current
directly below.
> +#endif
>
> CHECK_FULL_REGS(regs);
> /* Copy registers */
> @@ -672,6 +687,9 @@ int copy_thread(unsigned long clone_flag
> * function.
> */
> kregs->nip = *((unsigned long *)ret_from_fork);
> +
> + if (unlikely(test_tsk_thread_flag(tsk, TIF_DEBUG)))
> + copy_thread_hw_breakpoint(tsk, p, clone_flags);
> #else
> kregs->nip = (unsigned long)ret_from_fork;
> #endif
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
