Modify the ptrace code to use the hardware breakpoint interfaces for user-space.
Signed-off-by: K.Prasad <pra...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/ptrace.c | 48 +++++
Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/ptrace.c
===================================================================
--- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/ptrace.c
+++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/ptrace.c
@@ -37,6 +37,9 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
+#ifdef CONFIG_PPC64
+#include <asm/hw_breakpoint.h>
+#endif
/*
* does not yet catch signals sent when the child dies.
@@ -735,9 +738,22 @@ void user_disable_single_step(struct tas
clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}
+static void ptrace_triggered(struct hw_breakpoint *bp, struct pt_regs *regs)
+{
+ /*
+ * The SIGTRAP signal is generated automatically for us in do_dabr().
+ * We don't have to do anything here
+ */
+}
+
int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
unsigned long data)
{
+#ifdef CONFIG_PPC64
+ struct thread_struct *thread = &(task->thread);
+ struct hw_breakpoint *bp;
+ int ret;
+#endif
/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
* For embedded processors we support one DAC and no IAC's at the
* moment.
@@ -767,6 +783,38 @@ int ptrace_set_debugreg(struct task_stru
if (data && !(data & DABR_TRANSLATION))
return -EIO;
+#ifdef CONFIG_PPC64
+ bp = thread->hbp[0];
+ if ((data & ~HW_BREAKPOINT_ALIGN) == 0) {
+ if (bp) {
+ unregister_user_hw_breakpoint(task, bp);
+ kfree(bp);
+ thread->hbp[0] = NULL;
+ }
+ return 0;
+ }
+
+ if (bp) {
+ bp->info.type = data & DABR_DATA_RW;
+ task->thread.dabr = bp->info.address =
+ (data & ~HW_BREAKPOINT_ALIGN);
+ return modify_user_hw_breakpoint(task, bp);
+ }
+ bp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL);
+ if (!bp)
+ return -ENOMEM;
+
+ /* Store the type of breakpoint */
+ bp->info.type = data & DABR_DATA_RW;
+ bp->triggered = ptrace_triggered;
+ task->thread.dabr = bp->info.address = (data & ~HW_BREAKPOINT_ALIGN);
+
+ ret = register_user_hw_breakpoint(task, bp);
+ if (ret)
+ return ret;
+ set_tsk_thread_flag(task, TIF_DEBUG);
+#endif /* CONFIG_PPC64 */
+
/* Move contents to the DABR register */
task->thread.dabr = data;
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
