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>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index f9b30c6..10ade3c 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -180,9 +180,10 @@
}
#ifdef CONFIG_PPC64
-static unsigned long get_user_dscr(struct task_struct *task)
+static int get_user_dscr(struct task_struct *task, unsigned long *data)
{
- return task->thread.dscr;
+ *data = task->thread.dscr;
+ return 0;
}
static int set_user_dscr(struct task_struct *task, unsigned long dscr)
@@ -192,7 +193,7 @@
return 0;
}
#else
-static unsigned long get_user_dscr(struct task_struct *task)
+static int get_user_dscr(struct task_struct *task, unsigned long *data)
{
return -EIO;
}
@@ -216,19 +217,23 @@
/*
* Get contents of register REGNO in task TASK.
*/
-unsigned long ptrace_get_reg(struct task_struct *task, int regno)
+int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data)
{
- if (task->thread.regs == NULL)
+ if ((task->thread.regs == NULL) || !data)
return -EIO;
- if (regno == PT_MSR)
- return get_user_msr(task);
+ if (regno == PT_MSR) {
+ *data = get_user_msr(task);
+ return 0;
+ }
if (regno == PT_DSCR)
- return get_user_dscr(task);
+ return get_user_dscr(task, data);
- if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
- return ((unsigned long *)task->thread.regs)[regno];
+ if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) {
+ *data = ((unsigned long *)task->thread.regs)[regno];
+ return 0;
+ }
return -EIO;
}
@@ -1560,7 +1565,9 @@
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
- tmp = ptrace_get_reg(child, (int) index);
+ ret = ptrace_get_reg(child, (int) index, &tmp);
+ if (ret)
+ break;
} else {
unsigned int fpidx = index - PT_FPR0;