powerpc: fixing ptrace_get_reg to return an error

Currently ptrace_get_reg returns error as a value
what make impossible to tell whether it is a correct value or error code.

The patch adds a parameter which points to the real return data and
returns an error code.

As get_user_msr() never fails and it is used in multiple places so it has not
been changed by this patch.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 5f995681bc1d..becc08e6a65c 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -92,7 +92,8 @@ static inline long regs_return_value(struct pt_regs *regs)
         } while(0)
 
 struct task_struct;
-extern unsigned long ptrace_get_reg(struct task_struct *task, int regno);
+extern int ptrace_get_reg(struct task_struct *task, int regno,
+                          unsigned long *data);
 extern int ptrace_put_reg(struct task_struct *task, int regno,
                           unsigned long data);