1 files changed, 11 insertions, 11 deletions

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 3e581865c8e2..d185bdd95a4b 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -630,7 +630,8 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 static void
 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
-        bool failed;
+        bool stepping, failed;
+
         /* Are we from a system call? */
         if (syscall_get_nr(current, regs) >= 0) {
                 /* If so, check system call restarting.. */
@@ -654,12 +655,13 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
         }
 
         /*
-         * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
-         * flag so that register information in the sigcontext is correct.
+         * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now
+         * so that register information in the sigcontext is correct and
+         * then notify the tracer before entering the signal handler.
          */
-        if (unlikely(regs->flags & X86_EFLAGS_TF) &&
-            likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
-                regs->flags &= ~X86_EFLAGS_TF;
+        stepping = test_thread_flag(TIF_SINGLESTEP);
+        if (stepping)
+                user_disable_single_step(current);
 
         failed = (setup_rt_frame(ksig, regs) < 0);
         if (!failed) {
@@ -670,10 +672,8 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
                  * it might disable possible debug exception from the
                  * signal handler.
                  *
-                 * Clear TF when entering the signal handler, but
-                 * notify any tracer that was single-stepping it.
-                 * The tracer may want to single-step inside the
-                 * handler too.
+                 * Clear TF for the case when it wasn't set by debugger to
+                 * avoid the recursive send_sigtrap() in SIGTRAP handler.
                  */
                 regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
                 /*
@@ -682,7 +682,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
                 if (used_math())
                         fpu_reset_state(current);
         }
-        signal_setup_done(failed, ksig, test_thread_flag(TIF_SINGLESTEP));
+        signal_setup_done(failed, ksig, stepping);
 }
 
 #ifdef CONFIG_X86_32