[PATCH] powerpc/uaccess: fix warning/error with access_ok()

From: Christophe Leroy
Date: Thu Oct 18 2018 - 04:48:48 EST


With the following peace of code, the following compilation warning
is encountered:

if (_IOC_DIR(ioc) != _IOC_NONE) {
int verify = _IOC_DIR(ioc) & _IOC_READ ? VERIFY_WRITE : VERIFY_READ;

if (!access_ok(verify, ioarg, _IOC_SIZE(ioc))) {

drivers/platform/test/dev.c: In function âmy_ioctlâ:
drivers/platform/test/dev.c:219:7: warning: unused variable âverifyâ [-Wunused-variable]
int verify = _IOC_DIR(ioc) & _IOC_READ ? VERIFY_WRITE : VERIFY_READ;

This patch fixes it by handing the type to __access_ok(), changing it
to an inline function for PPC64 as already done for PPC32

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/uaccess.h | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 15bea9a0f260..97faf0353919 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -47,13 +47,16 @@ static inline void set_fs(mm_segment_t fs)
* This check is sufficient because there is a large enough
* gap between user addresses and the kernel addresses
*/
-#define __access_ok(addr, size, segment) \
- (((addr) <= (segment).seg) && ((size) <= (segment).seg))
+static inline int __access_ok(int type, unsigned long addr, unsigned long size,
+ mm_segment_t seg)
+{
+ return addr <= seg.seg && size <= seg.seg;
+}

#else

-static inline int __access_ok(unsigned long addr, unsigned long size,
- mm_segment_t seg)
+static inline int __access_ok(int type, unsigned long addr, unsigned long size,
+ mm_segment_t seg)
{
if (addr > seg.seg)
return 0;
@@ -64,7 +67,7 @@ static inline int __access_ok(unsigned long addr, unsigned long size,

#define access_ok(type, addr, size) \
(__chk_user_ptr(addr), \
- __access_ok((__force unsigned long)(addr), (size), get_fs()))
+ __access_ok((type), (__force unsigned long)(addr), (size), get_fs()))

/*
* These are the main single-value transfer routines. They automatically
--
2.13.3