1 files changed, 57 insertions, 25 deletions

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 9be35f348093..c625cdab76dd 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -2,7 +2,7 @@
  * SuperH process tracing
  *
  * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
- * Copyright (C) 2002 - 2008  Paul Mundt
+ * Copyright (C) 2002 - 2009  Paul Mundt
  *
  * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
  *
@@ -26,6 +26,7 @@
 #include <linux/tracehook.h>
 #include <linux/elf.h>
 #include <linux/regset.h>
+#include <linux/hw_breakpoint.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -63,33 +64,64 @@ static inline int put_stack_long(struct task_struct *task, int offset,
         return 0;
 }
 
-void user_enable_single_step(struct task_struct *child)
+void ptrace_triggered(struct perf_event *bp, int nmi,
+                      struct perf_sample_data *data, struct pt_regs *regs)
 {
-        /* Next scheduling will set up UBC */
-        if (child->thread.ubc_pc == 0)
-                ubc_usercnt += 1;
+        struct perf_event_attr attr;
+
+        /*
+         * Disable the breakpoint request here since ptrace has defined a
+         * one-shot behaviour for breakpoint exceptions.
+         */
+        attr = bp->attr;
+        attr.disabled = true;
+        modify_user_hw_breakpoint(bp, &attr);
+}
+
+static int set_single_step(struct task_struct *tsk, unsigned long addr)
+{
+        struct thread_struct *thread = &tsk->thread;
+        struct perf_event *bp;
+        struct perf_event_attr attr;
+
+        bp = thread->ptrace_bps[0];
+        if (!bp) {
+                hw_breakpoint_init(&attr);
+
+                attr.bp_addr = addr;
+                attr.bp_len = HW_BREAKPOINT_LEN_2;
+                attr.bp_type = HW_BREAKPOINT_R;
+
+                bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
+                if (IS_ERR(bp))
+                        return PTR_ERR(bp);
+
+                thread->ptrace_bps[0] = bp;
+        } else {
+                int err;
+
+                attr = bp->attr;
+                attr.bp_addr = addr;
+                err = modify_user_hw_breakpoint(bp, &attr);
+                if (unlikely(err))
+                        return err;
+        }
+
+        return 0;
+}
 
-        child->thread.ubc_pc = get_stack_long(child,
-                                offsetof(struct pt_regs, pc));
+void user_enable_single_step(struct task_struct *child)
+{
+        unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
 
         set_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+        set_single_step(child, pc);
 }
 
 void user_disable_single_step(struct task_struct *child)
 {
         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-
-        /*
-         * Ensure the UBC is not programmed at the next context switch.
-         *
-         * Normally this is not needed but there are sequences such as
-         * singlestep, signal delivery, and continue that leave the
-         * ubc_pc non-zero leading to spurious SIGTRAPs.
-         */
-        if (child->thread.ubc_pc != 0) {
-                ubc_usercnt -= 1;
-                child->thread.ubc_pc = 0;
-        }
 }
 
 /*
@@ -163,10 +195,10 @@ int fpregs_get(struct task_struct *target,
 
         if ((boot_cpu_data.flags & CPU_HAS_FPU))
                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-                                           &target->thread.fpu.hard, 0, -1);
+                                           &target->thread.xstate->hardfpu, 0, -1);
 
         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-                                   &target->thread.fpu.soft, 0, -1);
+                                   &target->thread.xstate->softfpu, 0, -1);
 }
 
 static int fpregs_set(struct task_struct *target,
@@ -184,10 +216,10 @@ static int fpregs_set(struct task_struct *target,
 
         if ((boot_cpu_data.flags & CPU_HAS_FPU))
                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                          &target->thread.fpu.hard, 0, -1);
+                                          &target->thread.xstate->hardfpu, 0, -1);
 
         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                  &target->thread.fpu.soft, 0, -1);
+                                  &target->thread.xstate->softfpu, 0, -1);
 }
 
 static int fpregs_active(struct task_struct *target,
@@ -333,7 +365,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                                 else
                                         tmp = 0;
                         } else
-                                tmp = ((long *)&child->thread.fpu)
+                                tmp = ((long *)child->thread.xstate)
                                         [(addr - (long)&dummy->fpu) >> 2];
                 } else if (addr == (long) &dummy->u_fpvalid)
                         tmp = !!tsk_used_math(child);
@@ -362,7 +394,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                 else if (addr >= (long) &dummy->fpu &&
                          addr < (long) &dummy->u_fpvalid) {
                         set_stopped_child_used_math(child);
-                        ((long *)&child->thread.fpu)
+                        ((long *)child->thread.xstate)
                                 [(addr - (long)&dummy->fpu) >> 2] = data;
                         ret = 0;
                 } else if (addr == (long) &dummy->u_fpvalid) {