1 files changed, 45 insertions, 0 deletions

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 82a41ac29386..4b1bd539ec47 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -554,6 +554,38 @@ static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
         ia64_psr(regs)->ss = 1;
 }
 
+static int __kprobes is_ia64_break_inst(struct pt_regs *regs)
+{
+        unsigned int slot = ia64_psr(regs)->ri;
+        unsigned int template, major_opcode;
+        unsigned long kprobe_inst;
+        unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip;
+        bundle_t bundle;
+
+        memcpy(&bundle, kprobe_addr, sizeof(bundle_t));
+        template = bundle.quad0.template;
+
+        /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
+        if (slot == 1 && bundle_encoding[template][1] == L)
+                slot++;
+
+        /* Get Kprobe probe instruction at given slot*/
+        get_kprobe_inst(&bundle, slot, &kprobe_inst, &major_opcode);
+
+        /* For break instruction,
+         * Bits 37:40 Major opcode to be zero
+         * Bits 27:32 X6 to be zero
+         * Bits 32:35 X3 to be zero
+         */
+        if (major_opcode || ((kprobe_inst >> 27) & 0x1FF) ) {
+                /* Not a break instruction */
+                return 0;
+        }
+
+        /* Is a break instruction */
+        return 1;
+}
+
 static int __kprobes pre_kprobes_handler(struct die_args *args)
 {
         struct kprobe *p;
@@ -601,6 +633,19 @@ static int __kprobes pre_kprobes_handler(struct die_args *args)
         p = get_kprobe(addr);
         if (!p) {
                 unlock_kprobes();
+                if (!is_ia64_break_inst(regs)) {
+                        /*
+                         * The breakpoint instruction was removed right
+                         * after we hit it.  Another cpu has removed
+                         * either a probepoint or a debugger breakpoint
+                         * at this address.  In either case, no further
+                         * handling of this interrupt is appropriate.
+                         */
+                        ret = 1;
+
+                }
+
+                /* Not one of our break, let kernel handle it */
                 goto no_kprobe;
         }