[POWERPC] Allow ptrace write to pt_regs trap and orig_r3

[firefly-linux-kernel-4.4.55.git] / arch / powerpc / kernel / ptrace.c

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index c9c330d35c17486b27d594041b2e29198c67670e..dd4837c4a68ab23baab922b1d1ba937f3db7617a 100644 (file)
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -75,10 +75,15 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
        if (task->thread.regs == NULL)
                return -EIO;
 
-       if (regno <= PT_MAX_PUT_REG) {
+       if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
                if (regno == PT_MSR)
                        data = (data & MSR_DEBUGCHANGE)
                                | (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
+               /* We prevent mucking around with the reserved area of trap
+                * which are used internally by the kernel
+                */
+               if (regno == PT_TRAP)
+                       data &= 0xfff0;
                ((unsigned long *)task->thread.regs)[regno] = data;
                return 0;
        }
@@ -409,8 +414,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                        break;
 
                CHECK_FULL_REGS(child->thread.regs);
-               if (index == PT_ORIG_R3)
-                       break;
                if (index < PT_FPR0) {
                        ret = ptrace_put_reg(child, index, data);
                } else {