Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Makefile: Use gcc to determine ARCH
  perf events, x86: Fix Intel Nehalem and Westmere last level cache event definitions
  hw_breakpoints, powerpc: Fix CONFIG_HAVE_HW_BREAKPOINT off-case in ptrace_set_debugreg()
  sh, hw_breakpoints: Fix racy access to ptrace breakpoints
  arm, hw_breakpoints: Fix racy access to ptrace breakpoints
  powerpc, hw_breakpoints: Fix racy access to ptrace breakpoints
  x86, hw_breakpoints: Fix racy access to ptrace breakpoints
  ptrace: Prepare to fix racy accesses on task breakpoints

2 files changed, 15 insertions, 1 deletions

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index a1147e5dd245..9178d5cc0b01 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -189,6 +189,10 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
                 child->ptrace = current->ptrace;
                 __ptrace_link(child, current->parent);
         }
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+        atomic_set(&child->ptrace_bp_refcnt, 1);
+#endif
 }
 
 /**
@@ -350,6 +354,13 @@ extern int task_current_syscall(struct task_struct *target, long *callno,
                                 unsigned long args[6], unsigned int maxargs,
                                 unsigned long *sp, unsigned long *pc);
 
-#endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+extern int ptrace_get_breakpoints(struct task_struct *tsk);
+extern void ptrace_put_breakpoints(struct task_struct *tsk);
+#else
+static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+#endif /* __KERNEL */
 
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 18d63cea2848..781abd137673 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1537,6 +1537,9 @@ struct task_struct {
                 unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
         } memcg_batch;
 #endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+        atomic_t ptrace_bp_refcnt;
+#endif
 };
 
 /* Future-safe accessor for struct task_struct's cpus_allowed. */