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 symbols: Remove incorrect open-coded container_of()
  perf record: Handle restrictive permissions in /proc/{kallsyms,modules}
  x86/kprobes: Prevent kprobes to probe on save_args()
  irq_work: Drop cmpxchg() result
  perf: Fix owner-list vs exit
  x86, hw_nmi: Move backtrace_mask declaration under ARCH_HAS_NMI_WATCHDOG
  tracing: Fix recursive user stack trace
  perf,hw_breakpoint: Initialize hardware api earlier
  x86: Ignore trap bits on single step exceptions
  tracing: Force arch_local_irq_* notrace for paravirt
  tracing: Fix module use of trace_bprintk()

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index ff15c9dcc25d..42c594254507 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -433,6 +433,10 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
         dr6_p = (unsigned long *)ERR_PTR(args->err);
         dr6 = *dr6_p;
 
+        /* If it's a single step, TRAP bits are random */
+        if (dr6 & DR_STEP)
+                return NOTIFY_DONE;
+
         /* Do an early return if no trap bits are set in DR6 */
         if ((dr6 & DR_TRAP_BITS) == 0)
                 return NOTIFY_DONE;