1 files changed, 10 insertions, 1 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 142d70c74b02..725ef4d17cd5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -526,6 +526,7 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 {
         struct task_struct *tsk = current;
+        int user_icebp = 0;
         unsigned long dr6;
         int si_code;
 
@@ -534,6 +535,14 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
         /* Filter out all the reserved bits which are preset to 1 */
         dr6 &= ~DR6_RESERVED;
 
+        /*
+         * If dr6 has no reason to give us about the origin of this trap,
+         * then it's very likely the result of an icebp/int01 trap.
+         * User wants a sigtrap for that.
+         */
+        if (!dr6 && user_mode(regs))
+                user_icebp = 1;
+
         /* Catch kmemcheck conditions first of all! */
         if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
                 return;
@@ -575,7 +584,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
                 regs->flags &= ~X86_EFLAGS_TF;
         }
         si_code = get_si_code(tsk->thread.debugreg6);
-        if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS))
+        if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
                 send_sigtrap(tsk, regs, error_code, si_code);
         preempt_conditional_cli(regs);