[PATCH 4.14 44/52] powerpc: Always initialize input array when calling epapr_hypercall()

From: Greg Kroah-Hartman
Date: Mon Mar 04 2019 - 03:27:56 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>

commit 186b8f1587c79c2fa04bfa392fdf084443e398c1 upstream.

Several callers to epapr_hypercall() pass an uninitialized stack
allocated array for the input arguments, presumably because they
have no input arguments. However this can produce errors like
this one

arch/powerpc/include/asm/epapr_hcalls.h:470:42: error: 'in' may be used uninitialized in this function [-Werror=maybe-uninitialized]
unsigned long register r3 asm("r3") = in[0];
~~^~~

Fix callers to this function to always zero-initialize the input
arguments array to prevent this.

Signed-off-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: "A. Wilcox" <awilfox@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/include/asm/epapr_hcalls.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/powerpc/include/asm/epapr_hcalls.h
+++ b/arch/powerpc/include/asm/epapr_hcalls.h
@@ -508,7 +508,7 @@ static unsigned long epapr_hypercall(uns

static inline long epapr_hypercall0_1(unsigned int nr, unsigned long *r2)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];
unsigned long r;

@@ -520,7 +520,7 @@ static inline long epapr_hypercall0_1(un

static inline long epapr_hypercall0(unsigned int nr)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];

return epapr_hypercall(in, out, nr);
@@ -528,7 +528,7 @@ static inline long epapr_hypercall0(unsi

static inline long epapr_hypercall1(unsigned int nr, unsigned long p1)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];

in[0] = p1;
@@ -538,7 +538,7 @@ static inline long epapr_hypercall1(unsi
static inline long epapr_hypercall2(unsigned int nr, unsigned long p1,
unsigned long p2)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];

in[0] = p1;
@@ -549,7 +549,7 @@ static inline long epapr_hypercall2(unsi
static inline long epapr_hypercall3(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];

in[0] = p1;
@@ -562,7 +562,7 @@ static inline long epapr_hypercall4(unsi
unsigned long p2, unsigned long p3,
unsigned long p4)
{
- unsigned long in[8];
+ unsigned long in[8] = {0};
unsigned long out[8];

in[0] = p1;