2 files changed, 14 insertions, 8 deletions

diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
index cee58624cb30..d561ff5a3d4d 100644
--- a/arch/x86/include/asm/uprobes.h
+++ b/arch/x86/include/asm/uprobes.h
@@ -46,8 +46,7 @@ struct arch_uprobe_task {
 #ifdef CONFIG_X86_64
         unsigned long                   saved_scratch_register;
 #endif
-#define UPROBE_CLEAR_TF                 (1 << 0)
-        unsigned int                    restore_flags;
+        unsigned int                    saved_tf;
 };
 
 extern int  arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 3b4aae68efe0..7e993d1f1992 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -653,7 +653,7 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
  * Skip these instructions as per the currently known x86 ISA.
  * 0x66* { 0x90 | 0x0f 0x1f | 0x0f 0x19 | 0x87 0xc0 }
  */
-bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
 {
         int i;
 
@@ -681,16 +681,21 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
         return false;
 }
 
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+        bool ret = __skip_sstep(auprobe, regs);
+        if (ret && (regs->flags & X86_EFLAGS_TF))
+                send_sig(SIGTRAP, current, 0);
+        return ret;
+}
+
 void arch_uprobe_enable_step(struct arch_uprobe *auprobe)
 {
         struct task_struct *task = current;
         struct arch_uprobe_task *autask = &task->utask->autask;
         struct pt_regs *regs = task_pt_regs(task);
 
-        autask->restore_flags = 0;
-        if (!(regs->flags & X86_EFLAGS_TF) &&
-            !(auprobe->fixups & UPROBE_FIX_SETF))
-                autask->restore_flags |= UPROBE_CLEAR_TF;
+        autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
 
         regs->flags |= X86_EFLAGS_TF;
         if (test_tsk_thread_flag(task, TIF_BLOCKSTEP))
@@ -707,6 +712,8 @@ void arch_uprobe_disable_step(struct arch_uprobe *auprobe)
          * SIGTRAP if we do not clear TF. We need to examine the opcode to
          * make it right.
          */
-        if (autask->restore_flags & UPROBE_CLEAR_TF)
+        if (autask->saved_tf)
+                send_sig(SIGTRAP, task, 0);
+        else if (!(auprobe->fixups & UPROBE_FIX_SETF))
                 regs->flags &= ~X86_EFLAGS_TF;
 }