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/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 5f99568..becc08e 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -92,7 +92,8 @@
} 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);
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;
diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c
index c0244e7..f51599e 100644
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -95,7 +95,9 @@
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
- tmp = ptrace_get_reg(child, index);
+ ret = ptrace_get_reg(child, index, &tmp);
+ if (ret)
+ break;
} else {
flush_fp_to_thread(child);
/*
@@ -148,7 +150,11 @@
tmp = ((u64 *)child->thread.fpr)
[FPRINDEX_3264(numReg)];
} else { /* register within PT_REGS struct */
- tmp = ptrace_get_reg(child, numReg);
+ unsigned long tmp2;
+ ret = ptrace_get_reg(child, numReg, &tmp2);
+ if (ret)
+ break;
+ tmp = tmp2;
}
reg32bits = ((u32*)&tmp)[part];
ret = put_user(reg32bits, (u32 __user *)data);
@@ -232,7 +238,10 @@
break;
CHECK_FULL_REGS(child->thread.regs);
if (numReg < PT_FPR0) {
- unsigned long freg = ptrace_get_reg(child, numReg);
+ unsigned long freg;
+ ret = ptrace_get_reg(child, numReg, &freg);
+ if (ret)
+ break;
if (index % 2)
freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
else