diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-07-09 15:22:45 +0100 |
|---|---|---|
| committer | Jason Liu <jason.hui.liu@nxp.com> | 2018-08-29 16:11:02 +0800 |
| commit | 824f531fc8f1023634304f08209b2622d2727e21 (patch) | |
| tree | 57716910abd98280c20aa03ccd4d2fa3bc079488 | |
| parent | 451340447893d6b08bc4ae18c3d2934e339623a0 (diff) | |
ARM: use __inttype() in get_user()
Borrow the x86 implementation of __inttype() to use in get_user() to
select an integer type suitable to temporarily hold the result value.
This is necessary to avoid propagating the volatile nature of the
result argument, which can cause the following warning:
lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
(cherry picked from commit d09fbb327d670737ab40fd8bbb0765ae06b8b739)
(cherry picked from commit 65bb2baffe6dde557abd138282024e2f3e0fa987)
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index b7e0125c0bbf..4a61f36c7397 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -115,6 +115,13 @@ static inline void set_fs(mm_segment_t fs) flag; }) /* + * This is a type: either unsigned long, if the argument fits into + * that type, or otherwise unsigned long long. + */ +#define __inttype(x) \ + __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) + +/* * Single-value transfer routines. They automatically use the right * size if we just have the right pointer type. Note that the functions * which read from user space (*get_*) need to take care not to leak @@ -183,7 +190,7 @@ extern int __get_user_64t_4(void *); ({ \ unsigned long __limit = current_thread_info()->addr_limit - 1; \ register const typeof(*(p)) __user *__p asm("r0") = (p);\ - register typeof(x) __r2 asm("r2"); \ + register __inttype(x) __r2 asm("r2"); \ register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ unsigned int __ua_flags = uaccess_save_and_enable(); \ |