1 files changed, 23 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c
index bc77834dbf43..59f419b935f2 100644
--- a/arch/powerpc/kernel/uprobes.c
+++ b/arch/powerpc/kernel/uprobes.c
@@ -31,6 +31,16 @@
 #define UPROBE_TRAP_NR  UINT_MAX
 
 /**
+ * is_trap_insn - check if the instruction is a trap variant
+ * @insn: instruction to be checked.
+ * Returns true if @insn is a trap variant.
+ */
+bool is_trap_insn(uprobe_opcode_t *insn)
+{
+        return (is_trap(*insn));
+}
+
+/**
  * arch_uprobe_analyze_insn
  * @mm: the probed address space.
  * @arch_uprobe: the probepoint information.
@@ -43,12 +53,6 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
         if (addr & 0x03)
                 return -EINVAL;
 
-        /*
-         * We currently don't support a uprobe on an already
-         * existing breakpoint instruction underneath
-         */
-        if (is_trap(auprobe->ainsn))
-                return -ENOTSUPP;
         return 0;
 }
 
@@ -188,3 +192,16 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
 
         return false;
 }
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
+{
+        unsigned long orig_ret_vaddr;
+
+        orig_ret_vaddr = regs->link;
+
+        /* Replace the return addr with trampoline addr */
+        regs->link = trampoline_vaddr;
+
+        return orig_ret_vaddr;
+}